/*
 * #%L
 * HAPI FHIR - Server Framework
 * %%
 * Copyright (C) 2014 - 2024 Smile CDR, Inc.
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package ca.uhn.fhir.rest.server;

import ca.uhn.fhir.context.ConfigurationException;
import ca.uhn.fhir.context.FhirContext;
import ca.uhn.fhir.context.RuntimeResourceDefinition;
import ca.uhn.fhir.context.api.AddProfileTagEnum;
import ca.uhn.fhir.context.api.BundleInclusionRule;
import ca.uhn.fhir.i18n.Msg;
import ca.uhn.fhir.interceptor.api.HookParams;
import ca.uhn.fhir.interceptor.api.IInterceptorService;
import ca.uhn.fhir.interceptor.api.Pointcut;
import ca.uhn.fhir.interceptor.executor.InterceptorService;
import ca.uhn.fhir.model.primitive.InstantDt;
import ca.uhn.fhir.parser.IParser;
import ca.uhn.fhir.rest.annotation.Destroy;
import ca.uhn.fhir.rest.annotation.IdParam;
import ca.uhn.fhir.rest.annotation.Initialize;
import ca.uhn.fhir.rest.api.Constants;
import ca.uhn.fhir.rest.api.EncodingEnum;
import ca.uhn.fhir.rest.api.MethodOutcome;
import ca.uhn.fhir.rest.api.PreferReturnEnum;
import ca.uhn.fhir.rest.api.RequestTypeEnum;
import ca.uhn.fhir.rest.api.RestOperationTypeEnum;
import ca.uhn.fhir.rest.api.server.BaseParseAction;
import ca.uhn.fhir.rest.api.server.IFhirVersionServer;
import ca.uhn.fhir.rest.api.server.IRestfulServer;
import ca.uhn.fhir.rest.api.server.RequestDetails;
import ca.uhn.fhir.rest.server.RestfulServerUtils.ResponseEncoding;
import ca.uhn.fhir.rest.server.exceptions.AuthenticationException;
import ca.uhn.fhir.rest.server.exceptions.BaseServerResponseException;
import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException;
import ca.uhn.fhir.rest.server.exceptions.NotModifiedException;
import ca.uhn.fhir.rest.server.exceptions.ResourceGoneException;
import ca.uhn.fhir.rest.server.exceptions.ResourceNotFoundException;
import ca.uhn.fhir.rest.server.interceptor.ExceptionHandlingInterceptor;
import ca.uhn.fhir.rest.server.interceptor.IServerInterceptor;
import ca.uhn.fhir.rest.server.method.BaseMethodBinding;
import ca.uhn.fhir.rest.server.method.ConformanceMethodBinding;
import ca.uhn.fhir.rest.server.method.MethodMatchEnum;
import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
import ca.uhn.fhir.rest.server.tenant.ITenantIdentificationStrategy;
import ca.uhn.fhir.util.CoverageIgnore;
import ca.uhn.fhir.util.OperationOutcomeUtil;
import ca.uhn.fhir.util.ReflectionUtil;
import ca.uhn.fhir.util.UrlPathTokenizer;
import ca.uhn.fhir.util.UrlUtil;
import ca.uhn.fhir.util.VersionUtil;
import com.google.common.collect.Lists;
import jakarta.annotation.Nonnull;
import jakarta.annotation.Nullable;
import jakarta.servlet.ServletException;
import jakarta.servlet.UnavailableException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.RandomStringUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;
import org.hl7.fhir.instance.model.api.IBaseConformance;
import org.hl7.fhir.instance.model.api.IBaseOperationOutcome;
import org.hl7.fhir.instance.model.api.IBaseResource;
import org.hl7.fhir.instance.model.api.IIdType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.io.Writer;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.jar.Manifest;

import static ca.uhn.fhir.util.StringUtil.toUtf8String;
import static java.util.stream.Collectors.toList;
import static org.apache.commons.lang3.StringUtils.isBlank;
import static org.apache.commons.lang3.StringUtils.isNotBlank;

/**
 * This class is the central class for the HAPI FHIR Plain Server framework.
 * <p>
 * See <a href="https://hapifhir.io/hapi-fhir/docs/server_plain/">HAPI FHIR Plain Server</a>
 * for information on how to use this framework.
 */
@SuppressWarnings("WeakerAccess")
public class RestfulServer extends HttpServlet implements IRestfulServer<ServletRequestDetails> {

        /**
         * All incoming requests will have an attribute added to {@link HttpServletRequest#getAttribute(String)}
         * with this key. The value will be a Java {@link Date} with the time that request processing began.
         */
        public static final String REQUEST_START_TIME = RestfulServer.class.getName() + "REQUEST_START_TIME";
        /**
         * Default setting for {@link #setETagSupport(ETagSupportEnum) ETag Support}: {@link ETagSupportEnum#ENABLED}
         */
        public static final ETagSupportEnum DEFAULT_ETAG_SUPPORT = ETagSupportEnum.ENABLED;
        /**
         * Requests will have an HttpServletRequest attribute set with this name, containing the servlet
         * context, in order to avoid a dependency on Servlet-API 3.0+
         */
        public static final String SERVLET_CONTEXT_ATTRIBUTE = "ca.uhn.fhir.rest.server.RestfulServer.servlet_context";
        /**
         * Default value for {@link #setDefaultPreferReturn(PreferReturnEnum)}
         */
        public static final PreferReturnEnum DEFAULT_PREFER_RETURN = PreferReturnEnum.REPRESENTATION;

        private static final ExceptionHandlingInterceptor DEFAULT_EXCEPTION_HANDLER = new ExceptionHandlingInterceptor();
        private static final Logger ourLog = LoggerFactory.getLogger(RestfulServer.class);
        private static final long serialVersionUID = 1L;
        private final List<Object> myPlainProviders = new ArrayList<>();
        private final List<IResourceProvider> myResourceProviders = new ArrayList<>();
        private IInterceptorService myInterceptorService;
        private BundleInclusionRule myBundleInclusionRule = BundleInclusionRule.BASED_ON_INCLUDES;
        private boolean myDefaultPrettyPrint = false;
        private EncodingEnum myDefaultResponseEncoding = EncodingEnum.JSON;
        private ETagSupportEnum myETagSupport = DEFAULT_ETAG_SUPPORT;
        private FhirContext myFhirContext;
        private boolean myIgnoreServerParsedRequestParameters = true;
        private String myImplementationDescription;
        private String myCopyright;
        private IPagingProvider myPagingProvider;
        private Integer myDefaultPageSize;
        private Integer myMaximumPageSize;
        private boolean myStatelessPagingDefault = false;
        private Lock myProviderRegistrationMutex = new ReentrantLock();
        private Map<String, ResourceBinding> myResourceNameToBinding = new HashMap<>();
        private IServerAddressStrategy myServerAddressStrategy = new IncomingRequestAddressStrategy();
        private ResourceBinding myServerBinding = new ResourceBinding();
        private ResourceBinding myGlobalBinding = new ResourceBinding();
        private ConformanceMethodBinding myServerConformanceMethod;
        private Object myServerConformanceProvider;
        private String myServerName = "HAPI FHIR Server";
        /**
         * This is configurable but by default we just use HAPI version
         */
        private String myServerVersion = createPoweredByHeaderProductVersion();

        private boolean myStarted;
        private boolean myUncompressIncomingContents = true;
        private ITenantIdentificationStrategy myTenantIdentificationStrategy;
        private PreferReturnEnum myDefaultPreferReturn = DEFAULT_PREFER_RETURN;
        private ElementsSupportEnum myElementsSupport = ElementsSupportEnum.EXTENDED;

        /**
         * Constructor. Note that if no {@link FhirContext} is passed in to the server (either through the constructor, or
         * through {@link #setFhirContext(FhirContext)}) the server will determine which
         * version of FHIR to support through classpath scanning. This is brittle, and it is highly recommended to explicitly
         * specify a FHIR version.
         */
        public RestfulServer() {
                this(null);
        }

        /**
         * Constructor
         */
        public RestfulServer(FhirContext theCtx) {
                this(theCtx, new InterceptorService("RestfulServer"));
        }

        public RestfulServer(FhirContext theCtx, IInterceptorService theInterceptorService) {
                myFhirContext = theCtx;
                setInterceptorService(theInterceptorService);
        }

        /**
         * @since 5.5.0
         */
        public ConformanceMethodBinding getServerConformanceMethod() {
                return myServerConformanceMethod;
        }

        private void addContentLocationHeaders(
                        RequestDetails theRequest,
                        HttpServletResponse servletResponse,
                        MethodOutcome response,
                        String resourceName) {
                if (response != null && response.getId() != null) {
                        addLocationHeader(theRequest, servletResponse, response, Constants.HEADER_LOCATION, resourceName);
                        addLocationHeader(theRequest, servletResponse, response, Constants.HEADER_CONTENT_LOCATION, resourceName);
                }
        }

        /**
         * This method is called prior to sending a response to incoming requests. It is used to add custom headers.
         * <p>
         * Use caution if overriding this method: it is recommended to call <code>super.addHeadersToResponse</code> to avoid
         * inadvertently disabling functionality.
         * </p>
         */
        public void addHeadersToResponse(HttpServletResponse theHttpResponse) {
                String poweredByHeader = createPoweredByHeader();
                if (isNotBlank(poweredByHeader)) {
                        theHttpResponse.addHeader(Constants.POWERED_BY_HEADER, poweredByHeader);
                }
        }

        private void addLocationHeader(
                        RequestDetails theRequest,
                        HttpServletResponse theResponse,
                        MethodOutcome response,
                        String headerLocation,
                        String resourceName) {
                StringBuilder b = new StringBuilder();
                b.append(theRequest.getFhirServerBase());
                b.append('/');
                b.append(resourceName);
                b.append('/');
                b.append(response.getId().getIdPart());
                if (response.getId().hasVersionIdPart()) {
                        b.append("/" + Constants.PARAM_HISTORY + "/");
                        b.append(response.getId().getVersionIdPart());
                }
                theResponse.addHeader(headerLocation, b.toString());
        }

        public RestfulServerConfiguration createConfiguration() {
                RestfulServerConfiguration result = new RestfulServerConfiguration();
                result.setResourceBindings(getResourceBindings());
                result.setServerBindings(getServerBindings());
                result.setGlobalBindings(getGlobalBindings());
                result.setImplementationDescription(getImplementationDescription());
                result.setServerVersion(getServerVersion());
                result.setServerName(getServerName());
                result.setFhirContext(getFhirContext());
                result.setServerAddressStrategy(myServerAddressStrategy);
                try (InputStream inputStream = getClass().getResourceAsStream("/META-INF/MANIFEST.MF")) {
                        if (inputStream != null) {
                                Manifest manifest = new Manifest(inputStream);
                                String value = manifest.getMainAttributes().getValue("Build-Time");
                                result.setConformanceDate(new InstantDt(value));
                        }
                } catch (Exception e) {
                        // fall through
                }
                result.computeSharedSupertypeForResourcePerName(getResourceProviders());
                return result;
        }

        private List<BaseMethodBinding> getGlobalBindings() {
                return myGlobalBinding.getMethodBindings();
        }

        protected List<String> createPoweredByAttributes() {
                return Lists.newArrayList(
                                "FHIR Server",
                                "FHIR " + myFhirContext.getVersion().getVersion().getFhirVersionString() + "/"
                                                + myFhirContext.getVersion().getVersion().name());
        }

        /**
         * Subclasses may override to provide their own powered by
         * header. Note that if you want to be nice and still credit HAPI
         * FHIR you could consider overriding
         * {@link #createPoweredByAttributes()} instead and adding your own
         * fragments to the list.
         */
        protected String createPoweredByHeader() {
                StringBuilder b = new StringBuilder();
                b.append(createPoweredByHeaderProductName());
                b.append(" ");
                b.append(createPoweredByHeaderProductVersion());
                b.append(" ");
                b.append(createPoweredByHeaderComponentName());
                b.append(" (");

                List<String> poweredByAttributes = createPoweredByAttributes();
                for (ListIterator<String> iter = poweredByAttributes.listIterator(); iter.hasNext(); ) {
                        if (iter.nextIndex() > 0) {
                                b.append("; ");
                        }
                        b.append(iter.next());
                }

                b.append(")");
                return b.toString();
        }

        /**
         * Subclasses my override
         *
         * @see #createPoweredByHeader()
         */
        protected String createPoweredByHeaderComponentName() {
                return "REST Server";
        }

        /**
         * Subclasses my override
         *
         * @see #createPoweredByHeader()
         */
        protected String createPoweredByHeaderProductName() {
                return "HAPI FHIR";
        }

        /**
         * Subclasses my override
         *
         * @see #createPoweredByHeader()
         */
        protected String createPoweredByHeaderProductVersion() {
                String version = VersionUtil.getVersion();
                if (VersionUtil.isSnapshot()) {
                        version = version + "/" + VersionUtil.getBuildNumber() + "/" + VersionUtil.getBuildDate();
                }
                return version;
        }

        @Override
        public void destroy() {
                if (getResourceProviders() != null) {
                        for (IResourceProvider iResourceProvider : getResourceProviders()) {
                                invokeDestroy(iResourceProvider);
                        }
                }

                if (myServerConformanceProvider != null) {
                        invokeDestroy(myServerConformanceProvider);
                }

                if (getPlainProviders() != null) {
                        for (Object next : getPlainProviders()) {
                                invokeDestroy(next);
                        }
                }

                if (myServerConformanceMethod != null) {
                        myServerConformanceMethod.close();
                }
                myResourceNameToBinding.values().stream()
                                .flatMap(t -> t.getMethodBindings().stream())
                                .forEach(t -> t.close());
                myGlobalBinding.getMethodBindings().forEach(t -> t.close());
                myServerBinding.getMethodBindings().forEach(t -> t.close());

                myResourceNameToBinding.clear();
                myGlobalBinding.getMethodBindings().clear();
                myServerBinding.getMethodBindings().clear();
        }

        /**
         * Figure out and return whichever method binding is appropriate for
         * the given request
         */
        public BaseMethodBinding determineResourceMethod(RequestDetails requestDetails, String requestPath) {
                RequestTypeEnum requestType = requestDetails.getRequestType();

                ResourceBinding resourceBinding = null;
                BaseMethodBinding resourceMethod = null;
                String resourceName = requestDetails.getResourceName();
                if (myServerConformanceMethod.incomingServerRequestMatchesMethod(requestDetails) != MethodMatchEnum.NONE) {
                        resourceMethod = myServerConformanceMethod;
                } else if (resourceName == null) {
                        resourceBinding = myServerBinding;
                } else {
                        resourceBinding = myResourceNameToBinding.get(resourceName);
                        if (resourceBinding == null) {
                                throwUnknownResourceTypeException(resourceName);
                        }
                }

                if (resourceMethod == null) {
                        if (resourceBinding != null) {
                                resourceMethod = resourceBinding.getMethod(requestDetails);
                        }
                        if (resourceMethod == null) {
                                resourceMethod = myGlobalBinding.getMethod(requestDetails);
                        }
                }
                if (resourceMethod == null) {
                        if (isBlank(requestPath)) {
                                throw new InvalidRequestException(
                                                Msg.code(287) + myFhirContext.getLocalizer().getMessage(RestfulServer.class, "rootRequest"));
                        }
                        throwUnknownFhirOperationException(requestDetails, requestPath, requestType);
                }
                return resourceMethod;
        }

        @Override
        protected void doDelete(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                handleRequest(RequestTypeEnum.DELETE, request, response);
        }

        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                handleRequest(RequestTypeEnum.GET, request, response);
        }

        @Override
        protected void doOptions(HttpServletRequest theReq, HttpServletResponse theResp)
                        throws ServletException, IOException {
                handleRequest(RequestTypeEnum.OPTIONS, theReq, theResp);
        }

        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                handleRequest(RequestTypeEnum.POST, request, response);
        }

        @Override
        protected void doPut(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException {
                handleRequest(RequestTypeEnum.PUT, request, response);
        }

        private void findResourceMethods(Object theProvider) {

                ourLog.debug("Scanning type for RESTful methods: {}", theProvider.getClass());
                int count = 0;

                Class<?> clazz = theProvider.getClass();
                Class<?> supertype = clazz.getSuperclass();
                while (!Object.class.equals(supertype)) {
                        count += findResourceMethodsOnInterfaces(theProvider, supertype.getInterfaces());
                        count += findResourceMethods(theProvider, supertype);
                        supertype = supertype.getSuperclass();
                }

                try {
                        count += findResourceMethodsOnInterfaces(theProvider, clazz.getInterfaces());
                        count += findResourceMethods(theProvider, clazz);
                } catch (ConfigurationException e) {
                        throw new ConfigurationException(
                                        Msg.code(288) + "Failure scanning class " + clazz.getSimpleName() + ": " + e.getMessage(), e);
                }
                if (count == 0) {
                        throw new ConfigurationException(
                                        Msg.code(289) + "Did not find any annotated RESTful methods on provider class "
                                                        + theProvider.getClass().getName());
                }
        }

        private int findResourceMethodsOnInterfaces(Object theProvider, Class<?>[] interfaces) {
                int count = 0;
                for (Class<?> anInterface : interfaces) {
                        count += findResourceMethodsOnInterfaces(theProvider, anInterface.getInterfaces());
                        count += findResourceMethods(theProvider, anInterface);
                }
                return count;
        }

        private int findResourceMethods(Object theProvider, Class<?> clazz) throws ConfigurationException {
                int count = 0;

                for (Method m : ReflectionUtil.getDeclaredMethods(clazz)) {
                        BaseMethodBinding foundMethodBinding = BaseMethodBinding.bindMethod(m, getFhirContext(), theProvider);
                        if (foundMethodBinding == null) {
                                continue;
                        }

                        count++;

                        if (foundMethodBinding instanceof ConformanceMethodBinding) {
                                myServerConformanceMethod = (ConformanceMethodBinding) foundMethodBinding;
                                if (myServerConformanceProvider == null) {
                                        myServerConformanceProvider = theProvider;
                                }
                                continue;
                        }

                        if (!Modifier.isPublic(m.getModifiers())) {
                                throw new ConfigurationException(Msg.code(290) + "Method '" + m.getName()
                                                + "' is not public, FHIR RESTful methods must be public");
                        }
                        if (Modifier.isStatic(m.getModifiers())) {
                                throw new ConfigurationException(Msg.code(291) + "Method '" + m.getName()
                                                + "' is static, FHIR RESTful methods must not be static");
                        }
                        ourLog.trace("Scanning public method: {}#{}", theProvider.getClass(), m.getName());

                        // Interceptor call: SERVER_PROVIDER_METHOD_BOUND
                        if (myInterceptorService.hasHooks(Pointcut.SERVER_PROVIDER_METHOD_BOUND)) {
                                HookParams params = new HookParams().add(BaseMethodBinding.class, foundMethodBinding);
                                BaseMethodBinding newMethodBinding = (BaseMethodBinding)
                                                myInterceptorService.callHooksAndReturnObject(Pointcut.SERVER_PROVIDER_METHOD_BOUND, params);
                                if (newMethodBinding == null) {
                                        ourLog.info(
                                                        "Method binding {} was discarded by interceptor and will not be registered",
                                                        foundMethodBinding);
                                        continue;
                                }
                                foundMethodBinding = newMethodBinding;
                        }

                        String resourceName = foundMethodBinding.getResourceName();
                        ResourceBinding resourceBinding;
                        if (resourceName == null) {
                                if (foundMethodBinding.isGlobalMethod()) {
                                        resourceBinding = myGlobalBinding;
                                } else {
                                        resourceBinding = myServerBinding;
                                }
                        } else {
                                RuntimeResourceDefinition definition = getFhirContext().getResourceDefinition(resourceName);
                                if (myResourceNameToBinding.containsKey(definition.getName())) {
                                        resourceBinding = myResourceNameToBinding.get(definition.getName());
                                } else {
                                        resourceBinding = new ResourceBinding();
                                        resourceBinding.setResourceName(resourceName);
                                        myResourceNameToBinding.put(resourceName, resourceBinding);
                                }
                        }

                        List<Class<?>> allowableParams = foundMethodBinding.getAllowableParamAnnotations();
                        if (allowableParams != null) {
                                for (Annotation[] nextParamAnnotations : m.getParameterAnnotations()) {
                                        for (Annotation annotation : nextParamAnnotations) {
                                                Package pack = annotation.annotationType().getPackage();
                                                if (pack.equals(IdParam.class.getPackage())) {
                                                        if (!allowableParams.contains(annotation.annotationType())) {
                                                                throw new ConfigurationException(Msg.code(292) + "Method[" + m
                                                                                + "] is not allowed to have a parameter annotated with " + annotation);
                                                        }
                                                }
                                        }
                                }
                        }

                        resourceBinding.addMethod(foundMethodBinding);
                        ourLog.trace(" * Method: {}#{} is a handler", theProvider.getClass(), m.getName());
                }

                return count;
        }

        /**
         * @deprecated As of HAPI FHIR 1.5, this property has been moved to
         * {@link FhirContext#setAddProfileTagWhenEncoding(AddProfileTagEnum)}
         */
        @Override
        @Deprecated
        public AddProfileTagEnum getAddProfileTag() {
                return myFhirContext.getAddProfileTagWhenEncoding();
        }

        /**
         * Sets the profile tagging behaviour for the server. When set to a value other than {@link AddProfileTagEnum#NEVER}
         * (which is the default), the server will automatically add a profile tag based on
         * the class of the resource(s) being returned.
         *
         * @param theAddProfileTag The behaviour enum (must not be null)
         * @deprecated As of HAPI FHIR 1.5, this property has been moved to
         * {@link FhirContext#setAddProfileTagWhenEncoding(AddProfileTagEnum)}
         */
        @Deprecated
        @CoverageIgnore
        public void setAddProfileTag(AddProfileTagEnum theAddProfileTag) {
                Validate.notNull(theAddProfileTag, "theAddProfileTag must not be null");
                myFhirContext.setAddProfileTagWhenEncoding(theAddProfileTag);
        }

        @Override
        public BundleInclusionRule getBundleInclusionRule() {
                return myBundleInclusionRule;
        }

        /**
         * Set how bundle factory should decide whether referenced resources should be included in bundles
         *
         * @param theBundleInclusionRule - inclusion rule (@see BundleInclusionRule for behaviors)
         */
        public void setBundleInclusionRule(BundleInclusionRule theBundleInclusionRule) {
                myBundleInclusionRule = theBundleInclusionRule;
        }

        /**
         * Returns the default encoding to return (XML/JSON) if an incoming request does not specify a preference (either
         * with the <code>_format</code> URL parameter, or with an <code>Accept</code> header
         * in the request. The default is {@link EncodingEnum#XML}. Will not return null.
         */
        @Override
        public EncodingEnum getDefaultResponseEncoding() {
                return myDefaultResponseEncoding;
        }

        /**
         * Sets the default encoding to return (XML/JSON) if an incoming request does not specify a preference (either with
         * the <code>_format</code> URL parameter, or with an <code>Accept</code> header in
         * the request. The default is {@link EncodingEnum#XML}.
         * <p>
         * Note when testing this feature: Some browsers will include "application/xml" in their Accept header, which means
         * that the
         * </p>
         */
        public void setDefaultResponseEncoding(EncodingEnum theDefaultResponseEncoding) {
                Validate.notNull(theDefaultResponseEncoding, "theDefaultResponseEncoding can not be null");
                myDefaultResponseEncoding = theDefaultResponseEncoding;
        }

        @Override
        public ETagSupportEnum getETagSupport() {
                return myETagSupport;
        }

        /**
         * Sets (enables/disables) the server support for ETags. Must not be <code>null</code>. Default is
         * {@link #DEFAULT_ETAG_SUPPORT}
         *
         * @param theETagSupport The ETag support mode
         */
        public void setETagSupport(ETagSupportEnum theETagSupport) {
                if (theETagSupport == null) {
                        throw new NullPointerException(Msg.code(293) + "theETagSupport can not be null");
                }
                myETagSupport = theETagSupport;
        }

        @Override
        public ElementsSupportEnum getElementsSupport() {
                return myElementsSupport;
        }

        /**
         * Sets the elements support mode.
         *
         * @see <a href="http://hapifhir.io/doc_rest_server.html#extended_elements_support">Extended Elements Support</a>
         */
        public void setElementsSupport(ElementsSupportEnum theElementsSupport) {
                Validate.notNull(theElementsSupport, "theElementsSupport must not be null");
                myElementsSupport = theElementsSupport;
        }

        /**
         * Gets the {@link FhirContext} associated with this server. For efficient processing, resource providers and plain
         * providers should generally use this context if one is needed, as opposed to
         * creating their own.
         */
        @Override
        public FhirContext getFhirContext() {
                if (myFhirContext == null) {
                        // TODO: Use of a deprecated method should be resolved.
                        myFhirContext = new FhirContext();
                }
                return myFhirContext;
        }

        public void setFhirContext(FhirContext theFhirContext) {
                Validate.notNull(theFhirContext, "FhirContext must not be null");
                myFhirContext = theFhirContext;
        }

        public String getImplementationDescription() {
                return myImplementationDescription;
        }

        public void setImplementationDescription(String theImplementationDescription) {
                myImplementationDescription = theImplementationDescription;
        }

        /**
         * Returns the server copyright (will be added to the CapabilityStatement). Note that FHIR allows Markdown in this string.
         */
        public String getCopyright() {
                return myCopyright;
        }

        /**
         * Sets the server copyright (will be added to the CapabilityStatement). Note that FHIR allows Markdown in this string.
         */
        public void setCopyright(String theCopyright) {
                myCopyright = theCopyright;
        }

        /**
         * Returns a list of all registered server interceptors
         *
         * @deprecated As of HAPI FHIR 3.8.0, use {@link #getInterceptorService()} to access the interceptor service. You can register and unregister interceptors using this service.
         */
        @Deprecated
        @Override
        public List<IServerInterceptor> getInterceptors_() {
                List<IServerInterceptor> retVal = getInterceptorService().getAllRegisteredInterceptors().stream()
                                .filter(t -> t instanceof IServerInterceptor)
                                .map(t -> (IServerInterceptor) t)
                                .collect(toList());
                return Collections.unmodifiableList(retVal);
        }

        /**
         * Returns the interceptor registry for this service. Use this registry to register and unregister
         *
         * @since 3.8.0
         */
        @Override
        public IInterceptorService getInterceptorService() {
                return myInterceptorService;
        }

        /**
         * Sets the interceptor registry for this service. Use this registry to register and unregister
         *
         * @since 3.8.0
         */
        public void setInterceptorService(@Nonnull IInterceptorService theInterceptorService) {
                Validate.notNull(theInterceptorService, "theInterceptorService must not be null");
                myInterceptorService = theInterceptorService;
        }

        /**
         * Sets (or clears) the list of interceptors
         *
         * @param theList The list of interceptors (may be null)
         * @deprecated As of HAPI FHIR 3.8.0, use {@link #getInterceptorService()} to access the interceptor service. You can register and unregister interceptors using this service.
         */
        @Deprecated
        public void setInterceptors(@Nonnull List<?> theList) {
                myInterceptorService.unregisterAllInterceptors();
                myInterceptorService.registerInterceptors(theList);
        }

        /**
         * Sets (or clears) the list of interceptors
         *
         * @param theInterceptors The list of interceptors (may be null)
         * @deprecated As of HAPI FHIR 3.8.0, use {@link #getInterceptorService()} to access the interceptor service. You can register and unregister interceptors using this service.
         */
        @Deprecated
        public void setInterceptors(IServerInterceptor... theInterceptors) {
                Validate.noNullElements(theInterceptors, "theInterceptors must not contain any null elements");
                setInterceptors(Arrays.asList(theInterceptors));
        }

        @Override
        public IPagingProvider getPagingProvider() {
                return myPagingProvider;
        }

        /**
         * Sets the paging provider to use, or <code>null</code> to use no paging (which is the default).
         * This will set defaultPageSize and maximumPageSize from the paging provider.
         */
        public void setPagingProvider(IPagingProvider thePagingProvider) {
                myPagingProvider = thePagingProvider;
                if (myPagingProvider != null) {
                        setDefaultPageSize(myPagingProvider.getDefaultPageSize());
                        setMaximumPageSize(myPagingProvider.getMaximumPageSize());
                }
        }

        @Override
        public Integer getDefaultPageSize() {
                return myDefaultPageSize;
        }

        /**
         * Sets the default page size to use, or <code>null</code> if no default page size
         */
        public void setDefaultPageSize(Integer thePageSize) {
                myDefaultPageSize = thePageSize;
        }

        @Override
        public Integer getMaximumPageSize() {
                return myMaximumPageSize;
        }

        /**
         * Sets the maximum page size to use, or <code>null</code> if no maximum page size
         */
        public void setMaximumPageSize(Integer theMaximumPageSize) {
                myMaximumPageSize = theMaximumPageSize;
        }

        /**
         * Provides the non-resource specific providers which implement method calls on this server
         *
         * @see #getResourceProviders()
         */
        public Collection<Object> getPlainProviders() {
                return myPlainProviders;
        }

        /**
         * Sets the non-resource specific providers which implement method calls on this server.
         *
         * @see #setResourceProviders(Collection)
         * @deprecated This method causes inconsistent behaviour depending on the order it is called in. Use {@link #registerProviders(Object...)} instead.
         */
        @Deprecated
        public void setPlainProviders(Object... theProv) {
                setPlainProviders(Arrays.asList(theProv));
        }

        /**
         * Sets the non-resource specific providers which implement method calls on this server.
         *
         * @see #setResourceProviders(Collection)
         * @deprecated This method causes inconsistent behaviour depending on the order it is called in. Use {@link #registerProviders(Object...)} instead.
         */
        @Deprecated
        public void setPlainProviders(Collection<Object> theProviders) {
                Validate.noNullElements(theProviders, "theProviders must not contain any null elements");

                myPlainProviders.clear();
                myPlainProviders.addAll(theProviders);
        }

        /**
         * Allows users of RestfulServer to override the getRequestPath method to let them build their custom request path
         * implementation
         *
         * @param requestFullPath    the full request path
         * @param servletContextPath the servelet context path
         * @param servletPath        the servelet path
         * @return created resource path
         */
        // NOTE: Don't make this a static method!! People want to override it
        protected String getRequestPath(String requestFullPath, String servletContextPath, String servletPath) {
                return requestFullPath.substring(escapedLength(servletContextPath) + escapedLength(servletPath));
        }

        public Collection<ResourceBinding> getResourceBindings() {
                return myResourceNameToBinding.values();
        }

        public Collection<BaseMethodBinding> getProviderMethodBindings(Object theProvider) {
                Set<BaseMethodBinding> retVal = new HashSet<>();
                for (ResourceBinding resourceBinding : getResourceBindings()) {
                        for (BaseMethodBinding methodBinding : resourceBinding.getMethodBindings()) {
                                if (theProvider.equals(methodBinding.getProvider())) {
                                        retVal.add(methodBinding);
                                }
                        }
                }

                return retVal;
        }

        /**
         * Provides the resource providers for this server
         */
        public List<IResourceProvider> getResourceProviders() {
                return Collections.unmodifiableList(myResourceProviders);
        }

        /**
         * Sets the resource providers for this server
         */
        public void setResourceProviders(IResourceProvider... theResourceProviders) {
                myResourceProviders.clear();
                if (theResourceProviders != null) {
                        myResourceProviders.addAll(Arrays.asList(theResourceProviders));
                }
        }

        /**
         * Sets the resource providers for this server
         */
        public void setResourceProviders(Collection<IResourceProvider> theProviders) {
                Validate.noNullElements(theProviders, "theProviders must not contain any null elements");

                myResourceProviders.clear();
                myResourceProviders.addAll(theProviders);
        }

        /**
         * Get the server address strategy, which is used to determine what base URL to provide clients to refer to this
         * server. Defaults to an instance of {@link IncomingRequestAddressStrategy}
         */
        public IServerAddressStrategy getServerAddressStrategy() {
                return myServerAddressStrategy;
        }

        /**
         * Provide a server address strategy, which is used to determine what base URL to provide clients to refer to this
         * server. Defaults to an instance of {@link IncomingRequestAddressStrategy}
         */
        public void setServerAddressStrategy(IServerAddressStrategy theServerAddressStrategy) {
                Validate.notNull(theServerAddressStrategy, "Server address strategy can not be null");
                myServerAddressStrategy = theServerAddressStrategy;
        }

        /**
         * Returns the server base URL (with no trailing '/') for a given request
         */
        public String getServerBaseForRequest(ServletRequestDetails theRequest) {
                String fhirServerBase;
                fhirServerBase =
                                myServerAddressStrategy.determineServerBase(getServletContext(), theRequest.getServletRequest());
                assert isNotBlank(fhirServerBase) : "Server Address Strategy did not return a value";

                if (fhirServerBase.endsWith("/")) {
                        fhirServerBase = fhirServerBase.substring(0, fhirServerBase.length() - 1);
                }

                if (myTenantIdentificationStrategy != null) {
                        fhirServerBase = myTenantIdentificationStrategy.massageServerBaseUrl(fhirServerBase, theRequest);
                }

                return fhirServerBase;
        }

        /**
         * Returns the method bindings for this server which are not specific to any particular resource type. This method is
         * internal to HAPI and developers generally do not need to interact with it. Use
         * with caution, as it may change.
         */
        public List<BaseMethodBinding> getServerBindings() {
                return myServerBinding.getMethodBindings();
        }

        /**
         * Returns the server conformance provider, which is the provider that is used to generate the server's conformance
         * (metadata) statement if one has been explicitly defined.
         * <p>
         * By default, the ServerConformanceProvider for the declared version of FHIR is used, but this can be changed, or
         * set to <code>null</code> to use the appropriate one for the given FHIR version.
         * </p>
         */
        public Object getServerConformanceProvider() {
                return myServerConformanceProvider;
        }

        /**
         * Returns the server conformance provider, which is the provider that is used to generate the server's conformance
         * (metadata) statement.
         * <p>
         * By default, the ServerConformanceProvider implementation for the declared version of FHIR is used, but this can be
         * changed, or set to <code>null</code> if you do not wish to export a conformance
         * statement.
         * </p>
         * This method should only be called before the server is initialized.
         * Calling it after the server has started is allowed, but you should be
         * very careful in this case that you only call it while no traffic is
         * hitting the server.
         *
         * @throws IllegalStateException Note that this method can only be called prior to {@link #init() initialization} and will throw an
         *                               {@link IllegalStateException} if called after that.
         */
        public void setServerConformanceProvider(@Nonnull Object theServerConformanceProvider) {
                Validate.notNull(theServerConformanceProvider, "theServerConformanceProvider must not be null");

                if (myServerConformanceProvider != null) {
                        unregisterProvider(myServerConformanceProvider);
                }

                // call the setRestfulServer() method to point the Conformance
                // Provider to this server instance. This is done to avoid
                // passing the server into the constructor. Having that sort
                // of cross linkage causes reference cycles in Spring wiring
                try {
                        Method setRestfulServer =
                                        theServerConformanceProvider.getClass().getMethod("setRestfulServer", RestfulServer.class);
                        if (setRestfulServer != null) {
                                setRestfulServer.invoke(theServerConformanceProvider, this);
                        }
                } catch (Exception e) {
                        ourLog.warn("Error calling IServerConformanceProvider.setRestfulServer", e);
                }
                myServerConformanceProvider = theServerConformanceProvider;

                findResourceMethods(myServerConformanceProvider);
        }

        /**
         * Gets the server's name, as exported in conformance profiles exported by the server. This is informational only,
         * but can be helpful to set with something appropriate.
         *
         * @see RestfulServer#setServerName(String)
         */
        public String getServerName() {
                return myServerName;
        }

        /**
         * Sets the server's name, as exported in conformance profiles exported by the server. This is informational only,
         * but can be helpful to set with something appropriate.
         */
        public void setServerName(String theServerName) {
                myServerName = theServerName;
        }

        /**
         * Gets the server's version, as exported in conformance profiles exported by the server. This is informational only,
         * but can be helpful to set with something appropriate.
         */
        public String getServerVersion() {
                return myServerVersion;
        }

        /**
         * Gets the server's version, as exported in conformance profiles exported by the server. This is informational only,
         * but can be helpful to set with something appropriate.
         */
        public void setServerVersion(String theServerVersion) {
                myServerVersion = theServerVersion;
        }

        @SuppressWarnings("WeakerAccess")
        protected void handleRequest(
                        RequestTypeEnum theRequestType, HttpServletRequest theRequest, HttpServletResponse theResponse)
                        throws ServletException, IOException {
                String fhirServerBase;
                ServletRequestDetails requestDetails = newRequestDetails(theRequestType, theRequest, theResponse);

                String requestId = getOrCreateRequestId(theRequest);
                requestDetails.setRequestId(requestId);
                addRequestIdToResponse(requestDetails, requestId);

                theRequest.setAttribute(SERVLET_CONTEXT_ATTRIBUTE, getServletContext());

                try {

                        /* ***********************************
                         * Parse out the request parameters
                         * ***********************************/

                        String requestFullPath = StringUtils.defaultString(theRequest.getRequestURI());
                        String servletPath = StringUtils.defaultString(theRequest.getServletPath());
                        StringBuffer requestUrl = theRequest.getRequestURL();
                        String servletContextPath = IncomingRequestAddressStrategy.determineServletContextPath(theRequest, this);

                        /*
                         * Just for debugging..
                         */
                        if (ourLog.isTraceEnabled()) {
                                ourLog.trace("Request FullPath: {}", requestFullPath);
                                ourLog.trace("Servlet Path: {}", servletPath);
                                ourLog.trace("Request Url: {}", requestUrl);
                                ourLog.trace("Context Path: {}", servletContextPath);
                        }

                        String completeUrl;
                        Map<String, String[]> params = null;
                        if (isNotBlank(theRequest.getQueryString())) {
                                completeUrl = requestUrl + "?" + theRequest.getQueryString();
                                /*
                                 * By default, we manually parse the request params (the URL params, or the body for
                                 * POST form queries) since Java containers can't be trusted to use UTF-8 encoding
                                 * when parsing. Specifically Tomcat 7 and Glassfish 4.0 use 8859-1 for some dumb
                                 * reason.... grr.....
                                 */
                                if (isIgnoreServerParsedRequestParameters()) {
                                        String contentType = theRequest.getHeader(Constants.HEADER_CONTENT_TYPE);
                                        if (theRequestType == RequestTypeEnum.POST
                                                        && isNotBlank(contentType)
                                                        && contentType.startsWith(Constants.CT_X_FORM_URLENCODED)) {
                                                String requestBody = toUtf8String(requestDetails.loadRequestContents());
                                                params = UrlUtil.parseQueryStrings(theRequest.getQueryString(), requestBody);
                                        } else if (theRequestType == RequestTypeEnum.GET) {
                                                params = UrlUtil.parseQueryString(theRequest.getQueryString());
                                        }
                                }
                        } else {
                                completeUrl = requestUrl.toString();
                        }

                        if (params == null) {

                                // If the request is coming in with a content-encoding, don't try to
                                // load the params from the content.
                                if (isNotBlank(theRequest.getHeader(Constants.HEADER_CONTENT_ENCODING))) {
                                        if (isNotBlank(theRequest.getQueryString())) {
                                                params = UrlUtil.parseQueryString(theRequest.getQueryString());
                                        } else {
                                                params = Collections.emptyMap();
                                        }
                                }

                                if (params == null) {
                                        params = new HashMap<>(theRequest.getParameterMap());
                                }
                        }

                        requestDetails.setParameters(params);

                        /* *************************
                         * Notify interceptors about the incoming request
                         * *************************/

                        // Interceptor: SERVER_INCOMING_REQUEST_PRE_PROCESSED
                        if (myInterceptorService.hasHooks(Pointcut.SERVER_INCOMING_REQUEST_PRE_PROCESSED)) {
                                HookParams preProcessedParams = new HookParams();
                                preProcessedParams.add(HttpServletRequest.class, theRequest);
                                preProcessedParams.add(HttpServletResponse.class, theResponse);
                                if (!myInterceptorService.callHooks(
                                                Pointcut.SERVER_INCOMING_REQUEST_PRE_PROCESSED, preProcessedParams)) {
                                        return;
                                }
                        }

                        String requestPath = getRequestPath(requestFullPath, servletContextPath, servletPath);

                        if (requestPath.length() > 0 && requestPath.charAt(0) == '/') {
                                requestPath = requestPath.substring(1);
                        }

                        IIdType id;
                        populateRequestDetailsFromRequestPath(requestDetails, requestPath);

                        fhirServerBase = getServerBaseForRequest(requestDetails);

                        if (theRequestType == RequestTypeEnum.PUT) {
                                String contentLocation = theRequest.getHeader(Constants.HEADER_CONTENT_LOCATION);
                                if (contentLocation != null) {
                                        id = myFhirContext.getVersion().newIdType();
                                        id.setValue(contentLocation);
                                        requestDetails.setId(id);
                                }
                        }

                        String acceptEncoding = theRequest.getHeader(Constants.HEADER_ACCEPT_ENCODING);
                        boolean respondGzip = false;
                        if (acceptEncoding != null) {
                                String[] parts = acceptEncoding.trim().split("\\s*,\\s*");
                                for (String string : parts) {
                                        if (string.equals("gzip")) {
                                                respondGzip = true;
                                                break;
                                        }
                                }
                        }
                        requestDetails.setRespondGzip(respondGzip);
                        requestDetails.setRequestPath(requestPath);
                        requestDetails.setFhirServerBase(fhirServerBase);
                        requestDetails.setCompleteUrl(completeUrl);

                        // Interceptor: SERVER_INCOMING_REQUEST_PRE_HANDLER_SELECTED
                        if (myInterceptorService.hasHooks(Pointcut.SERVER_INCOMING_REQUEST_PRE_HANDLER_SELECTED)) {
                                HookParams preProcessedParams = new HookParams();
                                preProcessedParams.add(HttpServletRequest.class, theRequest);
                                preProcessedParams.add(HttpServletResponse.class, theResponse);
                                preProcessedParams.add(RequestDetails.class, requestDetails);
                                preProcessedParams.add(ServletRequestDetails.class, requestDetails);
                                if (!myInterceptorService.callHooks(
                                                Pointcut.SERVER_INCOMING_REQUEST_PRE_HANDLER_SELECTED, preProcessedParams)) {
                                        return;
                                }
                        }

                        validateRequest(requestDetails);

                        BaseMethodBinding resourceMethod = determineResourceMethod(requestDetails, requestPath);

                        RestOperationTypeEnum operation = resourceMethod.getRestOperationType(requestDetails);
                        requestDetails.setRestOperationType(operation);

                        // Interceptor: SERVER_INCOMING_REQUEST_POST_PROCESSED
                        if (myInterceptorService.hasHooks(Pointcut.SERVER_INCOMING_REQUEST_POST_PROCESSED)) {
                                HookParams postProcessedParams = new HookParams();
                                postProcessedParams.add(RequestDetails.class, requestDetails);
                                postProcessedParams.add(ServletRequestDetails.class, requestDetails);
                                postProcessedParams.add(HttpServletRequest.class, theRequest);
                                postProcessedParams.add(HttpServletResponse.class, theResponse);
                                if (!myInterceptorService.callHooks(
                                                Pointcut.SERVER_INCOMING_REQUEST_POST_PROCESSED, postProcessedParams)) {
                                        return;
                                }
                        }

                        /*
                         * Actually invoke the server method. This call is to a HAPI method binding, which
                         * is an object that wraps a specific implementing (user-supplied) method, but
                         * handles its input and provides its output back to the client.
                         *
                         * This is basically the end of processing for a successful request, since the
                         * method binding replies to the client and closes the response.
                         */
                        resourceMethod.invokeServer(this, requestDetails);

                        // Invoke interceptors
                        HookParams hookParams = new HookParams();
                        hookParams.add(RequestDetails.class, requestDetails);
                        hookParams.add(ServletRequestDetails.class, requestDetails);
                        myInterceptorService.callHooks(Pointcut.SERVER_PROCESSING_COMPLETED_NORMALLY, hookParams);

                } catch (NotModifiedException | AuthenticationException e) {

                        HookParams handleExceptionParams = new HookParams();
                        handleExceptionParams.add(RequestDetails.class, requestDetails);
                        handleExceptionParams.add(ServletRequestDetails.class, requestDetails);
                        handleExceptionParams.add(HttpServletRequest.class, theRequest);
                        handleExceptionParams.add(HttpServletResponse.class, theResponse);
                        handleExceptionParams.add(BaseServerResponseException.class, e);
                        if (!myInterceptorService.callHooks(Pointcut.SERVER_HANDLE_EXCEPTION, handleExceptionParams)) {
                                return;
                        }

                        writeExceptionToResponse(theResponse, e);

                } catch (Throwable e) {

                        /*
                         * We have caught an exception during request processing. This might be because a handling method threw
                         * something they wanted to throw (e.g. UnprocessableEntityException because the request
                         * had business requirement problems) or it could be due to bugs (e.g. NullPointerException).
                         *
                         * First we let the interceptors have a crack at converting the exception into something HAPI can use
                         * (BaseServerResponseException)
                         */
                        HookParams preProcessParams = new HookParams();
                        preProcessParams.add(RequestDetails.class, requestDetails);
                        preProcessParams.add(ServletRequestDetails.class, requestDetails);
                        preProcessParams.add(HttpServletRequest.class, theRequest);
                        preProcessParams.add(HttpServletResponse.class, theResponse);
                        preProcessParams.add(Throwable.class, e);
                        BaseServerResponseException exception =
                                        (BaseServerResponseException) myInterceptorService.callHooksAndReturnObject(
                                                        Pointcut.SERVER_PRE_PROCESS_OUTGOING_EXCEPTION, preProcessParams);

                        /*
                         * If none of the interceptors converted the exception, default behaviour is to keep the exception as-is if it
                         * extends BaseServerResponseException, otherwise wrap it in an
                         * InternalErrorException.
                         */
                        if (exception == null) {
                                exception = DEFAULT_EXCEPTION_HANDLER.preProcessOutgoingException(requestDetails, e, theRequest);
                        }

                        /*
                         * If it's a 410 Gone, we want to include a location header in the response
                         * if we can, since that can include the resource version which is nice
                         * for the user.
                         */
                        if (exception instanceof ResourceGoneException) {
                                IIdType resourceId = ((ResourceGoneException) exception).getResourceId();
                                if (resourceId != null && resourceId.hasResourceType() && resourceId.hasIdPart()) {
                                        String baseUrl =
                                                        myServerAddressStrategy.determineServerBase(theRequest.getServletContext(), theRequest);
                                        resourceId = resourceId.withServerBase(baseUrl, resourceId.getResourceType());
                                        requestDetails.getResponse().addHeader(Constants.HEADER_LOCATION, resourceId.getValue());
                                }
                        }

                        /*
                         * Next, interceptors get a shot at handling the exception
                         */
                        HookParams handleExceptionParams = new HookParams();
                        handleExceptionParams.add(RequestDetails.class, requestDetails);
                        handleExceptionParams.add(ServletRequestDetails.class, requestDetails);
                        handleExceptionParams.add(HttpServletRequest.class, theRequest);
                        handleExceptionParams.add(HttpServletResponse.class, theResponse);
                        handleExceptionParams.add(BaseServerResponseException.class, exception);
                        if (!myInterceptorService.callHooks(Pointcut.SERVER_HANDLE_EXCEPTION, handleExceptionParams)) {
                                return;
                        }

                        /*
                         * If we're handling an exception, no summary mode should be applied
                         */
                        requestDetails.removeParameter(Constants.PARAM_SUMMARY);
                        requestDetails.removeParameter(Constants.PARAM_ELEMENTS);
                        requestDetails.removeParameter(Constants.PARAM_ELEMENTS + Constants.PARAM_ELEMENTS_EXCLUDE_MODIFIER);

                        /*
                         * If nobody handles it, default behaviour is to stream back the OperationOutcome to the client.
                         */
                        DEFAULT_EXCEPTION_HANDLER.handleException(requestDetails, exception, theRequest, theResponse);

                } finally {

                        HookParams params = new HookParams();
                        params.add(RequestDetails.class, requestDetails);
                        params.addIfMatchesType(ServletRequestDetails.class, requestDetails);
                        myInterceptorService.callHooks(Pointcut.SERVER_PROCESSING_COMPLETED, params);
                }
        }

        /**
         * Subclasses may override this to customize the way that the RequestDetails object is created. Generally speaking, the
         * right way to do this is to override this method, but call the super-implementation (<code>super.newRequestDetails</code>)
         * and then customize the returned object before returning it.
         *
         * @param theRequestType The HTTP request verb
         * @param theRequest     The servlet request
         * @param theResponse    The servlet response
         * @return A ServletRequestDetails instance to be passed to any resource providers, interceptors, etc. that are invoked as a part of serving this request.
         */
        @Nonnull
        protected ServletRequestDetails newRequestDetails(
                        RequestTypeEnum theRequestType, HttpServletRequest theRequest, HttpServletResponse theResponse) {
                ServletRequestDetails requestDetails = newRequestDetails();
                requestDetails.setServer(this);
                requestDetails.setRequestType(theRequestType);
                requestDetails.setServletRequest(theRequest);
                requestDetails.setServletResponse(theResponse);
                return requestDetails;
        }

        /**
         * @deprecated Deprecated in HAPI FHIR 4.1.0 - Users wishing to override this method should override {@link #newRequestDetails(RequestTypeEnum, HttpServletRequest, HttpServletResponse)} instead
         */
        @Deprecated
        protected ServletRequestDetails newRequestDetails() {
                return new ServletRequestDetails(getInterceptorService());
        }

        protected void addRequestIdToResponse(ServletRequestDetails theRequestDetails, String theRequestId) {
                theRequestDetails.getResponse().addHeader(Constants.HEADER_REQUEST_ID, theRequestId);
        }

        /**
         * Reads a request ID from the request headers via the {@link Constants#HEADER_REQUEST_ID}
         * header, or generates one if none is supplied.
         * <p>
         * Note that the generated request ID is a random 64-bit long integer encoded as
         * hexadecimal. It is not generated using any cryptographic algorithms or a secure
         * PRNG, so it should not be used for anything other than troubleshooting purposes.
         * </p>
         */
        protected String getOrCreateRequestId(HttpServletRequest theRequest) {
                String requestId = ServletRequestTracing.maybeGetRequestId(theRequest);

                // TODO can we delete this and newRequestId()
                //  and use ServletRequestTracing.getOrGenerateRequestId() instead?
                //  newRequestId() is protected.  Do you think anyone actually overrode it?
                if (isBlank(requestId)) {
                        int requestIdLength = Constants.REQUEST_ID_LENGTH;
                        requestId = newRequestId(requestIdLength);
                }

                return requestId;
        }

        /**
         * Generate a new request ID string. Subclasses may ovrride.
         */
        protected String newRequestId(int theRequestIdLength) {
                String requestId;
                requestId = RandomStringUtils.randomAlphanumeric(theRequestIdLength);
                return requestId;
        }

        protected void validateRequest(ServletRequestDetails theRequestDetails) {
                String[] elements = theRequestDetails.getParameters().get(Constants.PARAM_ELEMENTS);
                if (elements != null) {
                        for (String next : elements) {
                                if (next.indexOf(':') != -1) {
                                        throw new InvalidRequestException(Msg.code(295) + "Invalid _elements value: \"" + next + "\"");
                                }
                        }
                }

                elements = theRequestDetails
                                .getParameters()
                                .get(Constants.PARAM_ELEMENTS + Constants.PARAM_ELEMENTS_EXCLUDE_MODIFIER);
                if (elements != null) {
                        for (String next : elements) {
                                if (next.indexOf(':') != -1) {
                                        throw new InvalidRequestException(Msg.code(296) + "Invalid _elements value: \"" + next + "\"");
                                }
                        }
                }
        }

        /**
         * Initializes the server. Note that this method is final to avoid accidentally introducing bugs in implementations,
         * but subclasses may put initialization code in {@link #initialize()}, which is
         * called immediately before beginning initialization of the restful server's internal init.
         */
        @Override
        public final void init() throws ServletException {
                myProviderRegistrationMutex.lock();
                try {
                        initialize();

                        Object confProvider;
                        try {
                                ourLog.info("Initializing HAPI FHIR restful server running in "
                                                + getFhirContext().getVersion().getVersion().name() + " mode");

                                Collection<IResourceProvider> resourceProvider = getResourceProviders();
                                // 'true' tells registerProviders() that
                                // this call is part of initialization
                                registerProviders(resourceProvider, true);

                                Collection<Object> providers = getPlainProviders();
                                // 'true' tells registerProviders() that
                                // this call is part of initialization
                                registerProviders(providers, true);

                                confProvider = getServerConformanceProvider();
                                if (confProvider == null) {
                                        IFhirVersionServer versionServer =
                                                        (IFhirVersionServer) getFhirContext().getVersion().getServerVersion();
                                        confProvider = versionServer.createServerConformanceProvider(this);
                                }
                                setServerConformanceProvider(confProvider);

                                ourLog.trace("Invoking provider initialize methods");
                                if (getResourceProviders() != null) {
                                        for (IResourceProvider iResourceProvider : getResourceProviders()) {
                                                invokeInitialize(iResourceProvider);
                                        }
                                }

                                invokeInitialize(confProvider);
                                if (getPlainProviders() != null) {
                                        for (Object next : getPlainProviders()) {
                                                invokeInitialize(next);
                                        }
                                }

                                /*
                                 * This is a bit odd, but we have a placeholder @GetPage method for now
                                 * that gets the server to bind for the paging request. At some point
                                 * it would be nice to set things up so that client code could provide
                                 * an alternate implementation, but this isn't currently possible..
                                 */
                                findResourceMethods(new PageProvider());

                        } catch (Exception e) {
                                ourLog.error("An error occurred while loading request handlers!", e);
                                throw new ServletException(
                                                Msg.code(297) + "Failed to initialize FHIR Restful server: " + e.getMessage(), e);
                        }

                        myStarted = true;
                        ourLog.info("A FHIR has been lit on this server");
                } finally {
                        myProviderRegistrationMutex.unlock();
                }
        }

        /**
         * This method may be overridden by subclasses to do perform initialization that needs to be performed prior to the
         * server being used.
         *
         * @throws ServletException If the initialization failed. Note that you should consider throwing {@link UnavailableException}
         *                          (which extends {@link ServletException}), as this is a flag to the servlet container
         *                          that the servlet is not usable.
         */
        protected void initialize() throws ServletException {
                // nothing by default
        }

        private void invokeDestroy(Object theProvider) {
                invokeDestroy(theProvider, theProvider.getClass());
        }

        private void invokeDestroy(Object theProvider, Class<?> clazz) {
                for (Method m : ReflectionUtil.getDeclaredMethods(clazz)) {
                        Destroy destroy = m.getAnnotation(Destroy.class);
                        if (destroy != null) {
                                invokeInitializeOrDestroyMethod(theProvider, m, "destroy");
                        }
                }

                Class<?> supertype = clazz.getSuperclass();
                if (!Object.class.equals(supertype)) {
                        invokeDestroy(theProvider, supertype);
                }
        }

        private void invokeInitialize(Object theProvider) {
                invokeInitialize(theProvider, theProvider.getClass());
        }

        private void invokeInitialize(Object theProvider, Class<?> clazz) {
                for (Method m : ReflectionUtil.getDeclaredMethods(clazz)) {
                        Initialize initialize = m.getAnnotation(Initialize.class);
                        if (initialize != null) {
                                invokeInitializeOrDestroyMethod(theProvider, m, "initialize");
                        }
                }

                Class<?> supertype = clazz.getSuperclass();
                if (!Object.class.equals(supertype)) {
                        invokeInitialize(theProvider, supertype);
                }
        }

        private void invokeInitializeOrDestroyMethod(Object theProvider, Method m, String theMethodDescription) {

                Class<?>[] paramTypes = m.getParameterTypes();
                Object[] params = new Object[paramTypes.length];

                int index = 0;
                for (Class<?> nextParamType : paramTypes) {

                        if (RestfulServer.class.equals(nextParamType) || IRestfulServerDefaults.class.equals(nextParamType)) {
                                params[index] = this;
                        }

                        index++;
                }

                try {
                        m.invoke(theProvider, params);
                } catch (Exception e) {
                        ourLog.error("Exception occurred in " + theMethodDescription + " method '" + m.getName() + "'", e);
                }
        }

        /**
         * Should the server "pretty print" responses by default (requesting clients can always override this default by
         * supplying an <code>Accept</code> header in the request, or a <code>_pretty</code>
         * parameter in the request URL.
         * <p>
         * The default is <code>false</code>
         * </p>
         * <p>
         * Note that this setting is ignored by {@link ca.uhn.fhir.rest.server.interceptor.ResponseHighlighterInterceptor}
         * when streaming HTML, although even when that interceptor it used this setting will
         * still be honoured when streaming raw FHIR.
         * </p>
         *
         * @return Returns the default pretty print setting
         */
        @Override
        public boolean isDefaultPrettyPrint() {
                return myDefaultPrettyPrint;
        }

        /**
         * Should the server "pretty print" responses by default (requesting clients can always override this default by
         * supplying an <code>Accept</code> header in the request, or a <code>_pretty</code>
         * parameter in the request URL.
         * <p>
         * The default is <code>false</code>
         * </p>
         * <p>
         * Note that this setting is ignored by {@link ca.uhn.fhir.rest.server.interceptor.ResponseHighlighterInterceptor}
         * when streaming HTML, although even when that interceptor it used this setting will
         * still be honoured when streaming raw FHIR.
         * </p>
         *
         * @param theDefaultPrettyPrint The default pretty print setting
         */
        public void setDefaultPrettyPrint(boolean theDefaultPrettyPrint) {
                myDefaultPrettyPrint = theDefaultPrettyPrint;
        }

        /**
         * If set to <code>true</code> (the default is <code>true</code>) this server will not
         * use the parsed request parameters (URL parameters and HTTP POST form contents) but
         * will instead parse these values manually from the request URL and request body.
         * <p>
         * This is useful because many servlet containers (e.g. Tomcat, Glassfish) will use
         * ISO-8859-1 encoding to parse escaped URL characters instead of using UTF-8
         * as is specified by FHIR.
         * </p>
         */
        public boolean isIgnoreServerParsedRequestParameters() {
                return myIgnoreServerParsedRequestParameters;
        }

        /**
         * If set to <code>true</code> (the default is <code>true</code>) this server will not
         * use the parsed request parameters (URL parameters and HTTP POST form contents) but
         * will instead parse these values manually from the request URL and request body.
         * <p>
         * This is useful because many servlet containers (e.g. Tomcat, Glassfish) will use
         * ISO-8859-1 encoding to parse escaped URL characters instead of using UTF-8
         * as is specified by FHIR.
         * </p>
         */
        public void setIgnoreServerParsedRequestParameters(boolean theIgnoreServerParsedRequestParameters) {
                myIgnoreServerParsedRequestParameters = theIgnoreServerParsedRequestParameters;
        }

        /**
         * Should the server attempt to decompress incoming request contents (default is <code>true</code>). Typically this
         * should be set to <code>true</code> unless the server has other configuration to
         * deal with decompressing request bodies (e.g. a filter applied to the whole server).
         */
        public boolean isUncompressIncomingContents() {
                return myUncompressIncomingContents;
        }

        /**
         * Should the server attempt to decompress incoming request contents (default is <code>true</code>). Typically this
         * should be set to <code>true</code> unless the server has other configuration to
         * deal with decompressing request bodies (e.g. a filter applied to the whole server).
         */
        public void setUncompressIncomingContents(boolean theUncompressIncomingContents) {
                myUncompressIncomingContents = theUncompressIncomingContents;
        }

        private String resolveRequestPath(RequestDetails theRequestDetails, String theRequestPath) {
                if (myTenantIdentificationStrategy != null) {
                        theRequestPath = myTenantIdentificationStrategy.resolveRelativeUrl(theRequestPath, theRequestDetails);
                }
                return theRequestPath;
        }

        public void populateRequestDetailsFromRequestPath(RequestDetails theRequestDetails, String theRequestPath) {
                String resolvedRequestPath = resolveRequestPath(theRequestDetails, theRequestPath);
                UrlPathTokenizer tok = new UrlPathTokenizer(resolvedRequestPath);

                if (myTenantIdentificationStrategy != null) {
                        myTenantIdentificationStrategy.extractTenant(tok, theRequestDetails);
                }

                IIdType id = null;
                String operation = null;
                String compartment = null;
                String resourceName = null;
                if (tok.hasMoreTokens()) {
                        resourceName = tok.nextTokenUnescapedAndSanitized();
                        if (partIsOperation(resourceName)) {
                                operation = resourceName;
                                resourceName = null;
                        }
                }
                theRequestDetails.setResourceName(resourceName);

                if (tok.hasMoreTokens()) {
                        String nextString = tok.nextTokenUnescapedAndSanitized();
                        if (partIsOperation(nextString)) {
                                operation = nextString;
                        } else {
                                id = myFhirContext.getVersion().newIdType();
                                id.setParts(null, resourceName, UrlUtil.unescape(nextString), null);
                        }
                }

                if (tok.hasMoreTokens()) {
                        String nextString = tok.nextTokenUnescapedAndSanitized();
                        if (nextString.equals(Constants.PARAM_HISTORY)) {
                                if (tok.hasMoreTokens()) {
                                        String versionString = tok.nextTokenUnescapedAndSanitized();
                                        if (id == null) {
                                                throw new InvalidRequestException(
                                                                Msg.code(298) + "Don't know how to handle request path: " + resolvedRequestPath);
                                        }
                                        id.setParts(null, resourceName, id.getIdPart(), UrlUtil.unescape(versionString));
                                } else {
                                        operation = Constants.PARAM_HISTORY;
                                }
                        } else if (partIsOperation(nextString)) {
                                if (operation != null) {
                                        throw new InvalidRequestException(
                                                        Msg.code(299) + "URL Path contains two operations: " + resolvedRequestPath);
                                }
                                operation = nextString;
                        } else {
                                compartment = nextString;
                        }
                }

                // Secondary is for things like ..../_tags/_delete
                String secondaryOperation = null;

                while (tok.hasMoreTokens()) {
                        String nextString = tok.nextTokenUnescapedAndSanitized();
                        if (operation == null) {
                                operation = nextString;
                        } else if (secondaryOperation == null) {
                                secondaryOperation = nextString;
                        } else {
                                throw new InvalidRequestException(Msg.code(300) + "URL path has unexpected token '" + nextString
                                                + "' at the end: " + resolvedRequestPath);
                        }
                }

                theRequestDetails.setId(id);
                theRequestDetails.setOperation(operation);
                theRequestDetails.setSecondaryOperation(secondaryOperation);
                theRequestDetails.setCompartmentName(compartment);
        }

        /**
         * Registers an interceptor. This method is a convenience method which calls
         * <code>getInterceptorService().registerInterceptor(theInterceptor);</code>
         *
         * @param theInterceptor The interceptor, must not be null
         */
        public void registerInterceptor(Object theInterceptor) {
                Validate.notNull(theInterceptor, "Interceptor can not be null");
                getInterceptorService().registerInterceptor(theInterceptor);
        }

        /**
         * Register a single provider. This could be a Resource Provider or a "plain" provider not associated with any
         * resource.
         */
        public void registerProvider(Object provider) {
                if (provider != null) {
                        Collection<Object> providerList = new ArrayList<>(1);
                        providerList.add(provider);
                        registerProviders(providerList);
                }
        }

        /**
         * Register a group of providers. These could be Resource Providers (classes implementing {@link IResourceProvider}) or "plain" providers, or a mixture of the two.
         *
         * @param theProviders a {@code Collection} of theProviders. The parameter could be null or an empty {@code Collection}
         */
        public void registerProviders(Object... theProviders) {
                Validate.noNullElements(theProviders);
                registerProviders(Arrays.asList(theProviders));
        }

        /**
         * Register a group of theProviders. These could be Resource Providers, "plain" theProviders or a mixture of the two.
         *
         * @param theProviders a {@code Collection} of theProviders. The parameter could be null or an empty {@code Collection}
         */
        public void registerProviders(Collection<?> theProviders) {
                Validate.noNullElements(theProviders, "theProviders must not contain any null elements");

                myProviderRegistrationMutex.lock();
                try {
                        if (!myStarted) {
                                for (Object provider : theProviders) {
                                        ourLog.debug("Registration of provider ["
                                                        + provider.getClass().getName() + "] will be delayed until FHIR server startup");
                                        if (provider instanceof IResourceProvider) {
                                                myResourceProviders.add((IResourceProvider) provider);
                                        } else {
                                                myPlainProviders.add(provider);
                                        }
                                }
                                return;
                        }
                } finally {
                        myProviderRegistrationMutex.unlock();
                }
                registerProviders(theProviders, false);
        }

        /*
         * Inner method to actually register theProviders
         */
        protected void registerProviders(@Nullable Collection<?> theProviders, boolean inInit) {
                Validate.noNullElements(theProviders, "theProviders must not contain any null elements");

                List<IResourceProvider> newResourceProviders = new ArrayList<>();
                List<Object> newPlainProviders = new ArrayList<>();

                if (theProviders != null) {
                        for (Object provider : theProviders) {
                                if (provider instanceof IResourceProvider) {
                                        IResourceProvider rsrcProvider = (IResourceProvider) provider;
                                        Class<? extends IBaseResource> resourceType = rsrcProvider.getResourceType();
                                        if (resourceType == null) {
                                                throw new NullPointerException(Msg.code(301) + "getResourceType() on class '"
                                                                + rsrcProvider.getClass().getCanonicalName() + "' returned null");
                                        }
                                        if (!inInit) {
                                                myResourceProviders.add(rsrcProvider);
                                        }
                                        newResourceProviders.add(rsrcProvider);
                                } else {
                                        if (!inInit) {
                                                myPlainProviders.add(provider);
                                        }
                                        newPlainProviders.add(provider);
                                }
                        }
                        if (!newResourceProviders.isEmpty()) {
                                ourLog.info(
                                                "Added {} resource provider(s). Total {}",
                                                newResourceProviders.size(),
                                                myResourceProviders.size());
                                for (IResourceProvider provider : newResourceProviders) {
                                        findResourceMethods(provider);
                                }
                        }
                        if (!newPlainProviders.isEmpty()) {
                                ourLog.info("Added {} plain provider(s). Total {}", newPlainProviders.size(), myPlainProviders.size());
                                for (Object provider : newPlainProviders) {
                                        findResourceMethods(provider);
                                }
                        }
                        if (!inInit) {
                                ourLog.trace("Invoking provider initialize methods");
                                if (!newResourceProviders.isEmpty()) {
                                        for (IResourceProvider provider : newResourceProviders) {
                                                invokeInitialize(provider);
                                        }
                                }
                                if (!newPlainProviders.isEmpty()) {
                                        for (Object provider : newPlainProviders) {
                                                invokeInitialize(provider);
                                        }
                                }
                        }
                }
        }

        /*
         * Remove registered RESTful methods for a Provider (and all superclasses) when it is being unregistered
         */
        private void removeResourceMethods(Object theProvider) {
                ourLog.info("Removing RESTful methods for: {}", theProvider.getClass());
                Class<?> clazz = theProvider.getClass();
                Class<?> supertype = clazz.getSuperclass();
                Collection<String> resourceNames = new ArrayList<>();
                while (!Object.class.equals(supertype)) {
                        removeResourceMethods(theProvider, supertype, resourceNames);
                        removeResourceMethodsOnInterfaces(theProvider, supertype.getInterfaces(), resourceNames);
                        supertype = supertype.getSuperclass();
                }
                removeResourceMethods(theProvider, clazz, resourceNames);
                removeResourceMethodsOnInterfaces(theProvider, clazz.getInterfaces(), resourceNames);
                removeResourceNameBindings(resourceNames, theProvider);
        }

        private void removeResourceNameBindings(Collection<String> resourceNames, Object theProvider) {
                for (String resourceName : resourceNames) {
                        ResourceBinding resourceBinding = myResourceNameToBinding.get(resourceName);
                        if (resourceBinding == null) {
                                continue;
                        }

                        for (Iterator<BaseMethodBinding> it =
                                                        resourceBinding.getMethodBindings().iterator();
                                        it.hasNext(); ) {
                                BaseMethodBinding binding = it.next();
                                if (theProvider.equals(binding.getProvider())) {
                                        it.remove();
                                        ourLog.info("{} binding of {} was removed", resourceName, binding);
                                }
                        }

                        if (resourceBinding.getMethodBindings().isEmpty()) {
                                myResourceNameToBinding.remove(resourceName);
                        }
                }
        }

        private void removeResourceMethodsOnInterfaces(
                        Object theProvider, Class<?>[] interfaces, Collection<String> resourceNames) {
                for (Class<?> anInterface : interfaces) {
                        removeResourceMethods(theProvider, anInterface, resourceNames);
                        removeResourceMethodsOnInterfaces(theProvider, anInterface.getInterfaces(), resourceNames);
                }
        }

        /*
         * Collect the set of RESTful methods for a single class when it is being unregistered
         */
        private void removeResourceMethods(Object theProvider, Class<?> clazz, Collection<String> resourceNames)
                        throws ConfigurationException {
                for (Method m : ReflectionUtil.getDeclaredMethods(clazz)) {
                        BaseMethodBinding foundMethodBinding = BaseMethodBinding.bindMethod(m, getFhirContext(), theProvider);
                        if (foundMethodBinding == null) {
                                continue; // not a bound method
                        }
                        if (foundMethodBinding instanceof ConformanceMethodBinding) {
                                myServerConformanceMethod = null;
                                continue;
                        }
                        String resourceName = foundMethodBinding.getResourceName();
                        if (!resourceNames.contains(resourceName)) {
                                resourceNames.add(resourceName);
                        }
                }
        }

        public Object returnResponse(
                        ServletRequestDetails theRequest,
                        BaseParseAction<?> outcome,
                        int operationStatus,
                        boolean allowPrefer,
                        MethodOutcome response,
                        String resourceName)
                        throws IOException {
                HttpServletResponse servletResponse = theRequest.getServletResponse();
                servletResponse.setStatus(operationStatus);
                servletResponse.setCharacterEncoding(Constants.CHARSET_NAME_UTF8);
                addHeadersToResponse(servletResponse);
                if (allowPrefer) {
                        addContentLocationHeaders(theRequest, servletResponse, response, resourceName);
                }
                Writer writer;
                if (outcome != null) {
                        ResponseEncoding encoding = RestfulServerUtils.determineResponseEncodingWithDefault(theRequest);
                        servletResponse.setContentType(encoding.getResourceContentType());
                        writer = servletResponse.getWriter();
                        IParser parser = encoding.getEncoding().newParser(getFhirContext());
                        parser.setPrettyPrint(RestfulServerUtils.prettyPrintResponse(this, theRequest));
                        outcome.execute(parser, writer);
                } else {
                        servletResponse.setContentType(Constants.CT_TEXT_WITH_UTF8);
                        writer = servletResponse.getWriter();
                }
                return writer;
        }

        @Override
        protected void service(HttpServletRequest theReq, HttpServletResponse theResp)
                        throws ServletException, IOException {
                theReq.setAttribute(REQUEST_START_TIME, new Date());

                RequestTypeEnum method;
                try {
                        method = RequestTypeEnum.valueOf(theReq.getMethod());
                } catch (IllegalArgumentException e) {
                        super.service(theReq, theResp);
                        return;
                }

                switch (method) {
                        case DELETE:
                                doDelete(theReq, theResp);
                                break;
                        case GET:
                                doGet(theReq, theResp);
                                break;
                        case OPTIONS:
                                doOptions(theReq, theResp);
                                break;
                        case POST:
                                doPost(theReq, theResp);
                                break;
                        case PUT:
                                doPut(theReq, theResp);
                                break;
                        case PATCH:
                        case TRACE:
                        case TRACK:
                        case HEAD:
                        case CONNECT:
                        default:
                                handleRequest(method, theReq, theResp);
                                break;
                }
        }

        /**
         * Sets the non-resource specific providers which implement method calls on this server
         *
         * @see #setResourceProviders(Collection)
         */
        public void setProviders(Object... theProviders) {
                Validate.noNullElements(theProviders, "theProviders must not contain any null elements");

                myPlainProviders.clear();
                if (theProviders != null) {
                        myPlainProviders.addAll(Arrays.asList(theProviders));
                }
        }

        /**
         * If provided (default is <code>null</code>), the tenant identification
         * strategy provides a mechanism for a multitenant server to identify which tenant
         * a given request corresponds to.
         */
        public void setTenantIdentificationStrategy(ITenantIdentificationStrategy theTenantIdentificationStrategy) {
                myTenantIdentificationStrategy = theTenantIdentificationStrategy;
        }

        protected void throwUnknownFhirOperationException(
                        RequestDetails requestDetails, String requestPath, RequestTypeEnum theRequestType) {
                FhirContext fhirContext = myFhirContext;
                throwUnknownFhirOperationException(requestDetails, requestPath, theRequestType, fhirContext);
        }

        protected void throwUnknownResourceTypeException(String theResourceName) {
                /* perform a 'distinct' in case there are multiple concrete IResourceProviders declared for the same FHIR-Resource. (A concrete IResourceProvider for Patient@Read and a separate concrete for Patient@Search for example */
                /* perform a 'sort' to provide an easier to read alphabetized list (vs how the different FHIR-resource IResourceProviders happened to be registered */
                List<String> knownDistinctAndSortedResourceTypes = myResourceProviders.stream()
                                .map(t -> t.getResourceType().getSimpleName())
                                .distinct()
                                .sorted()
                                .collect(toList());
                throw new ResourceNotFoundException(Msg.code(302) + "Unknown resource type '" + theResourceName
                                + "' - Server knows how to handle: " + knownDistinctAndSortedResourceTypes);
        }

        /**
         * Unregisters an interceptor. This method is a convenience method which calls
         * <code>getInterceptorService().unregisterInterceptor(theInterceptor);</code>
         *
         * @param theInterceptor The interceptor, must not be null
         */
        public void unregisterInterceptor(Object theInterceptor) {
                Validate.notNull(theInterceptor, "Interceptor can not be null");
                getInterceptorService().unregisterInterceptor(theInterceptor);
        }

        /**
         * Unregister one provider (either a Resource provider or a plain provider)
         */
        public void unregisterProvider(Object provider) {
                if (provider != null) {
                        Collection<Object> providerList = new ArrayList<>(1);
                        providerList.add(provider);
                        unregisterProviders(providerList);
                }
        }

        /**
         * Unregister a {@code Collection} of providers
         */
        public void unregisterProviders(Collection<?> providers) {
                if (providers != null) {
                        for (Object provider : providers) {
                                removeResourceMethods(provider);
                                if (provider instanceof IResourceProvider) {
                                        myResourceProviders.remove(provider);
                                } else {
                                        myPlainProviders.remove(provider);
                                }
                                invokeDestroy(provider);
                        }
                }
        }

        /**
         * Unregisters all plain and resource providers (but not the conformance provider).
         */
        public void unregisterAllProviders() {
                unregisterAllProviders(myPlainProviders);
                unregisterAllProviders(myResourceProviders);
        }

        private void unregisterAllProviders(List<?> theProviders) {
                while (theProviders.size() > 0) {
                        unregisterProvider(theProviders.get(0));
                }
        }

        private void writeExceptionToResponse(HttpServletResponse theResponse, BaseServerResponseException theException)
                        throws IOException {
                theResponse.setStatus(theException.getStatusCode());
                addHeadersToResponse(theResponse);
                if (theException.hasResponseHeaders()) {
                        for (Entry<String, List<String>> nextEntry :
                                        theException.getResponseHeaders().entrySet()) {
                                for (String nextValue : nextEntry.getValue()) {
                                        if (isNotBlank(nextValue)) {
                                                theResponse.addHeader(nextEntry.getKey(), nextValue);
                                        }
                                }
                        }
                }
                theResponse.setContentType("text/plain");
                theResponse.setCharacterEncoding("UTF-8");
                String message = UrlUtil.sanitizeUrlPart(theException.getMessage());
                theResponse.getWriter().write(message);
        }

        /**
         * By default, server create/update/patch/transaction methods return a copy of the resource
         * as it was stored. This may be overridden by the client using the
         * <code>Prefer</code> header.
         * <p>
         * This setting changes the default behaviour if no Prefer header is supplied by the client.
         * The default is {@link PreferReturnEnum#REPRESENTATION}
         * </p>
         *
         * @see <a href="http://hl7.org/fhir/http.html#ops">HL7 FHIR Specification</a> section on the Prefer header
         */
        @Override
        public PreferReturnEnum getDefaultPreferReturn() {
                return myDefaultPreferReturn;
        }

        /**
         * By default, server create/update/patch/transaction methods return a copy of the resource
         * as it was stored. This may be overridden by the client using the
         * <code>Prefer</code> header.
         * <p>
         * This setting changes the default behaviour if no Prefer header is supplied by the client.
         * The default is {@link PreferReturnEnum#REPRESENTATION}
         * </p>
         *
         * @see <a href="http://hl7.org/fhir/http.html#ops">HL7 FHIR Specification</a> section on the Prefer header
         */
        public void setDefaultPreferReturn(PreferReturnEnum theDefaultPreferReturn) {
                Validate.notNull(theDefaultPreferReturn, "theDefaultPreferReturn must not be null");
                myDefaultPreferReturn = theDefaultPreferReturn;
        }

        /**
         * Create a CapabilityStatement based on the given request
         */
        public IBaseConformance getCapabilityStatement(ServletRequestDetails theRequestDetails) {
                // Create a cloned request details so we can make it indicate that this is a capabilities request
                ServletRequestDetails requestDetails = new ServletRequestDetails(theRequestDetails);
                requestDetails.setRestOperationType(RestOperationTypeEnum.METADATA);

                return myServerConformanceMethod.provideCapabilityStatement(this, requestDetails);
        }

        /**
         * Count length of URL string, but treating unescaped sequences (e.g. ' ') as their unescaped equivalent (%20)
         */
        protected static int escapedLength(String theServletPath) {
                int delta = 0;
                for (int i = 0; i < theServletPath.length(); i++) {
                        char next = theServletPath.charAt(i);
                        if (next == ' ') {
                                delta = delta + 2;
                        }
                }
                return theServletPath.length() + delta;
        }

        public static void throwUnknownFhirOperationException(
                        RequestDetails requestDetails,
                        String requestPath,
                        RequestTypeEnum theRequestType,
                        FhirContext theFhirContext) {
                String message = theFhirContext
                                .getLocalizer()
                                .getMessage(
                                                RestfulServer.class,
                                                "unknownMethod",
                                                theRequestType.name(),
                                                requestPath,
                                                requestDetails.getParameters().keySet());

                IBaseOperationOutcome oo = OperationOutcomeUtil.newInstance(theFhirContext);
                OperationOutcomeUtil.addIssue(theFhirContext, oo, "error", message, null, "not-supported");

                throw new InvalidRequestException(Msg.code(303) + message, oo);
        }

        private static boolean partIsOperation(String nextString) {
                return nextString.length() > 0
                                && (nextString.charAt(0) == '_'
                                                || nextString.charAt(0) == '$'
                                                || nextString.equals(Constants.URL_TOKEN_METADATA));
        }

        //      /**
        //       * Returns the read method binding for the given resource type, or
        //       * returns <code>null</code> if not
        //       * @param theResourceType The resource type, e.g. "Patient"
        //       * @return The read method binding, or null
        //       */
        //      public ReadMethodBinding findReadMethodBinding(String theResourceType) {
        //              ReadMethodBinding retVal = null;
        //
        //              ResourceBinding type = myResourceNameToBinding.get(theResourceType);
        //              if (type != null) {
        //                      for (BaseMethodBinding<?> next : type.getMethodBindings()) {
        //                              if (next instanceof ReadMethodBinding) {
        //                                      retVal = (ReadMethodBinding) next;
        //                              }
        //                      }
        //              }
        //
        //              return retVal;
        //      }
}