001 /*****************************************************************************
002 * Copyright (C) PicoContainer Organization. All rights reserved. *
003 * ------------------------------------------------------------------------- *
004 * The software in this package is published under the terms of the BSD *
005 * style license a copy of which has been included with this distribution in *
006 * the LICENSE.txt file. *
007 * *
008 * Original code by *
009 *****************************************************************************/
010 package org.picocontainer.injectors;
011
012 import org.picocontainer.ComponentMonitor;
013 import org.picocontainer.NameBinding;
014 import org.picocontainer.Parameter;
015 import org.picocontainer.PicoContainer;
016 import org.picocontainer.annotations.Bind;
017
018 import java.lang.annotation.Annotation;
019 import java.lang.reflect.AccessibleObject;
020 import java.lang.reflect.Field;
021 import java.lang.reflect.InvocationTargetException;
022 import java.lang.reflect.Type;
023 import java.security.AccessController;
024 import java.security.PrivilegedAction;
025 import java.util.ArrayList;
026 import java.util.Arrays;
027 import java.util.Collections;
028 import java.util.List;
029 import java.util.Set;
030
031 /**
032 * Injection happens after instantiation, and fields are marked as
033 * injection points via a named field.
034 */
035 @SuppressWarnings("serial")
036 public class NamedFieldInjector<T> extends AbstractFieldInjector<T> {
037
038 private final List<String> fieldNames;
039
040 public NamedFieldInjector(Object key,
041 Class<?> impl,
042 Parameter[] parameters,
043 ComponentMonitor componentMonitor,
044 String fieldNames) {
045
046 super(key, impl, parameters, componentMonitor, true);
047 this.fieldNames = Arrays.asList(fieldNames.trim().split(" "));
048 }
049
050 @Override
051 protected void initializeInjectionMembersAndTypeLists() {
052 injectionMembers = new ArrayList<AccessibleObject>();
053 List<Annotation> bindingIds = new ArrayList<Annotation>();
054 final List<Type> typeList = new ArrayList<Type>();
055 final Field[] fields = getFields();
056 for (final Field field : fields) {
057 if (isNamedForInjection(field)) {
058 injectionMembers.add(field);
059 typeList.add(box(field.getType()));
060 bindingIds.add(getBinding(field));
061 }
062 }
063 injectionTypes = typeList.toArray(new Type[0]);
064 bindings = bindingIds.toArray(new Annotation[0]);
065 }
066
067 private Annotation getBinding(Field field) {
068 Annotation[] annotations = field.getAnnotations();
069 for (Annotation annotation : annotations) {
070 if (annotation.annotationType().isAnnotationPresent(Bind.class)) {
071 return annotation;
072 }
073 }
074 return null;
075 }
076
077 protected boolean isNamedForInjection(Field field) {
078 return fieldNames.contains(field.getName());
079 }
080
081 private Field[] getFields() {
082 return AccessController.doPrivileged(new PrivilegedAction<Field[]>() {
083 public Field[] run() {
084 return getComponentImplementation().getDeclaredFields();
085 }
086 });
087 }
088
089
090 protected Object injectIntoMember(AccessibleObject member, Object componentInstance, Object toInject)
091 throws IllegalAccessException, InvocationTargetException {
092 Field field = (Field) member;
093 field.setAccessible(true);
094 field.set(componentInstance, toInject);
095 return null;
096 }
097
098 @Override
099 public String getDescriptor() {
100 return "NamedFieldInjector-";
101 }
102
103 @Override
104 protected NameBinding makeParameterNameImpl(final AccessibleObject member) {
105 return new NameBinding() {
106 public String getName() {
107 return ((Field) member).getName();
108 }
109 };
110 }
111
112 protected Object memberInvocationReturn(Object lastReturn, AccessibleObject member, Object instance) {
113 return instance;
114 }
115
116 List<String> getInjectionFieldNames() {
117 return Collections.unmodifiableList(fieldNames);
118 }
119
120
121 }