com.google.gdata.client.http

Class HttpGDataRequest

java.lang.Object

com.google.gdata.client.http.HttpGDataRequest

All Implemented Interfaces:

Service.GDataRequest

Direct Known Subclasses:

GoogleGDataRequest

public class HttpGDataRequest
extends Object
implements Service.GDataRequest

The HttpGDataRequest class provides a basic implementation of the GDataRequest interface over HTTP.

See Also:

Service.GDataRequest

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HttpGDataRequest.Factory The HttpGDataRequest.Factory class is a factory class for constructing new HttpGDataRequest instances.

Nested classes/interfaces inherited from interface com.google.gdata.client.Service.GDataRequest

Service.GDataRequest.RequestType

Field Summary

Fields

Modifier and Type	Field and Description
protected HttpAuthToken	authToken The auth token used for this request, may be null.
protected HttpUrlConnectionSource	connectionSource Source of HttpURLConnection instances.
protected int	connectTimeout The connection timeout for this request.
protected boolean	executed Indicates whether request execution has taken place.
protected boolean	expectsInput True if the request type expects input from the client.
protected boolean	hasOutput True if the request type returns output to the client.
protected HttpURLConnection	httpConn Underlying HTTP connection to the GData service.
protected ContentType	inputType Contains the content type of the request data
static String	METHOD_OVERRIDE_HEADER Deprecated. Use GDataProtocol.Header#METHOD_OVERRIDE instead
static String	METHOD_OVERRIDE_PROPERTY If this system property is set to true, the GData HTTP client library will use POST to send data to the associated GData service and will specify the actual method using the METHOD_OVERRIDE_HEADER HTTP header.
protected int	readTimeout The read timeout for this request.
protected URL	requestUrl The request URL provided by the client.
protected Service.GDataRequest.RequestType	type The GData request type.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HttpGDataRequest() Protected default constructor for testing.
protected	HttpGDataRequest(Service.GDataRequest.RequestType type, URL requestUrl, ContentType inputType, HttpAuthToken authToken, Map<String,String> headerMap, Map<String,String> privateHeaderMap, HttpUrlConnectionSource connectionSource) Constructs a new HttpGDataRequest instance of the specified RequestType, targeting the specified URL.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	checkResponse() Called after a request is executed to process the response and generate an appropriate exception (on failure).
void	end() Ends all processing associated with this request and releases any transient resources (such as open data streams) required for execution.
void	execute() Executes the GData service request.
HttpURLConnection	getConnection() Returns the URLConnection instance that represents the underlying connection to the GData service that will be used by this request.
ParseSource	getParseSource() Returns a parse source that can be used to read response data from the GData service.
protected HttpURLConnection	getRequestConnection(URL requestUrl) Obtains a connection to the GData service.
ContentType	getRequestContentType() Returns the ContentType of the data that will be written to the service by this request or null if no data is written to the server by the request.
OutputStream	getRequestStream() Returns a stream that can be used to write request data to the GData service.
URL	getRequestUrl() Returns the URL that is the target of the GData request
XmlWriter	getRequestWriter()
ContentType	getResponseContentType() Returns the content type of the GData response.
DateTime	getResponseDateHeader(String headerName) Returns the value of a header containing a header or null if no response header of this type exists or it could not be parsed as a valid date.
String	getResponseHeader(String headerName) Returns the value of the specified response header name or null if no response header of this type exists.
InputStream	getResponseStream() Returns an input stream that can be used to read response data from the GData service.
protected void	handleErrorResponse() Handles an error response received while executing a GData service request.
void	setConnectTimeout(int timeout) Sets the number of milliseconds to wait for a connection to the remote GData service before timing out.
void	setEtag(String etag) Sets the entity tag value that will be used to conditionalize the request if not null.
void	setHeader(String name, String value) Sets a request header (and logs it, if logging is enabled)
void	setIfModifiedSince(DateTime conditionDate) Sets the If-Modified-Since date precondition to be applied to the request.
void	setMethod(String method)
void	setPrivateHeader(String name, String value) Sets request header (and log just the name but not the value, if logging is enabled)
void	setReadTimeout(int timeout) Sets the number of milliseconds to wait for a response from the remote GData service before timing out.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

METHOD_OVERRIDE_PROPERTY

public static final String METHOD_OVERRIDE_PROPERTY

If this system property is set to true, the GData HTTP client library will use POST to send data to the associated GData service and will specify the actual method using the METHOD_OVERRIDE_HEADER HTTP header. This can be used as a workaround for HTTP proxies or gateways that do not handle PUT or DELETE HTTP methods properly. If the system property is false, the regular PUT and DELETE HTTP verbs will be used.

See Also:

Constant Field Values

METHOD_OVERRIDE_HEADER

@Deprecated
public static final String METHOD_OVERRIDE_HEADER

Deprecated. Use GDataProtocol.Header#METHOD_OVERRIDE instead

Name of HTTP header containing the method name that overrides the normal HTTP method.

See Also:

Constant Field Values

connectionSource

protected final HttpUrlConnectionSource connectionSource

Source of HttpURLConnection instances.

httpConn

protected HttpURLConnection httpConn

Underlying HTTP connection to the GData service.

requestUrl

protected URL requestUrl

The request URL provided by the client.

type

protected Service.GDataRequest.RequestType type

The GData request type.

executed

protected boolean executed

Indicates whether request execution has taken place. Set to true if executed, false otherwise.

expectsInput

protected boolean expectsInput

True if the request type expects input from the client.

inputType

protected ContentType inputType

Contains the content type of the request data

hasOutput

protected boolean hasOutput

True if the request type returns output to the client.

connectTimeout

protected int connectTimeout

The connection timeout for this request. A value of -1 means no value has been configured (use JDK default timeout behavior).

readTimeout

protected int readTimeout

The read timeout for this request. A value of -1 means no value has been configured (use JDK default timeout behavior).

authToken

protected final HttpAuthToken authToken

The auth token used for this request, may be null.

Constructor Detail

HttpGDataRequest

protected HttpGDataRequest(Service.GDataRequest.RequestType type,
                URL requestUrl,
                ContentType inputType,
                HttpAuthToken authToken,
                Map<String,String> headerMap,
                Map<String,String> privateHeaderMap,
                HttpUrlConnectionSource connectionSource)
                    throws IOException

Constructs a new HttpGDataRequest instance of the specified RequestType, targeting the specified URL.

Parameters:

type - type of GDataRequest.

requestUrl - request target URL.

inputType - the content type of request data (or null).

authToken - the auth token used for this request (or null).

headerMap - a set of headers to be included in each request

privateHeaderMap - a set of headers to be included in each request

connectionSource - source of HttpURLConnections

Throws:

IOException - on error initializating service connection.

HttpGDataRequest

protected HttpGDataRequest()

Protected default constructor for testing.

Method Detail

getRequestUrl

public URL getRequestUrl()

Description copied from interface: Service.GDataRequest

Returns the URL that is the target of the GData request

Specified by:

getRequestUrl in interface Service.GDataRequest

getRequestContentType

public ContentType getRequestContentType()

Description copied from interface: Service.GDataRequest

Returns the ContentType of the data that will be written to the service by this request or null if no data is written to the server by the request.

Specified by:

getRequestContentType in interface Service.GDataRequest

getRequestConnection

protected HttpURLConnection getRequestConnection(URL requestUrl)
                                          throws IOException

Obtains a connection to the GData service.

Throws:

IOException

setConnectTimeout

public void setConnectTimeout(int timeout)

Description copied from interface: Service.GDataRequest

Sets the number of milliseconds to wait for a connection to the remote GData service before timing out.

Specified by:

setConnectTimeout in interface Service.GDataRequest

Parameters:

timeout - the read timeout. A value of zero indicates an infinite timeout.

See Also:

URLConnection.setConnectTimeout(int)

setReadTimeout

public void setReadTimeout(int timeout)

Description copied from interface: Service.GDataRequest

Sets the number of milliseconds to wait for a response from the remote GData service before timing out.

Specified by:

setReadTimeout in interface Service.GDataRequest

Parameters:

timeout - the read timeout. A value of zero indicates an infinite timeout.

See Also:

URLConnection.setReadTimeout(int)

setIfModifiedSince

public void setIfModifiedSince(DateTime conditionDate)

Description copied from interface: Service.GDataRequest

Sets the If-Modified-Since date precondition to be applied to the request. If this precondition is set, then the request will be performed only if the target resource has been modified since the specified date; otherwise, a NotModifiedException will be thrown. The default value is null, indicating no precondition.

Specified by:

setIfModifiedSince in interface Service.GDataRequest

Parameters:

conditionDate - the date that should be used to limit the operation on the target resource. The operation will only be performed if the resource has been modified later than the specified date.

setEtag

public void setEtag(String etag)

Description copied from interface: Service.GDataRequest

Sets the entity tag value that will be used to conditionalize the request if not null. For a query requests, the tag will cause the target resource to be returned if the resource entity tag does not match the specified value (i.e. if the resource has not changed). For update or delete request types, the entity tag value is used to indicate that the requested operation should occur only if the specified etag value does match the specified value (i.e. if the resource has changed). A request entity tag value may not be associated with other request types.

Specified by:

setEtag in interface Service.GDataRequest

getRequestStream

public OutputStream getRequestStream()
                              throws IOException

Description copied from interface: Service.GDataRequest

Returns a stream that can be used to write request data to the GData service.

Specified by:

getRequestStream in interface Service.GDataRequest

Returns:

OutputStream that can be used to write GData request data.

Throws:

IOException - error obtaining the request output stream.

getRequestWriter

public XmlWriter getRequestWriter()
                           throws IOException

Throws:

IOException

setMethod

public void setMethod(String method)
               throws ProtocolException

Throws:

ProtocolException

setHeader

public void setHeader(String name,
             String value)

Description copied from interface: Service.GDataRequest

Sets a request header (and logs it, if logging is enabled)

Specified by:

setHeader in interface Service.GDataRequest

Parameters:

name - the header name

value - the header value

setPrivateHeader

public void setPrivateHeader(String name,
                    String value)

Description copied from interface: Service.GDataRequest

Sets request header (and log just the name but not the value, if logging is enabled)

Specified by:

setPrivateHeader in interface Service.GDataRequest

Parameters:

name - the header name

value - the header value

execute

public void execute()
             throws IOException,
                    ServiceException

Description copied from interface: Service.GDataRequest

Executes the GData service request.

Specified by:

execute in interface Service.GDataRequest

Throws:

IOException - error writing to or reading from GData service.

ResourceNotFoundException - invalid request target resource.

ServiceException - system error executing request.

checkResponse

protected void checkResponse()
                      throws IOException,
                             ServiceException

Called after a request is executed to process the response and generate an appropriate exception (on failure).

Throws:

IOException

ServiceException

handleErrorResponse

protected void handleErrorResponse()
                            throws ServiceException,
                                   IOException

Handles an error response received while executing a GData service request. Throws a ServiceException or one of its subclasses, depending on the failure conditions.

Throws:

ServiceException - exception describing the failure.

IOException - error reading the error response from the GData service.

getResponseContentType

public ContentType getResponseContentType()

Description copied from interface: Service.GDataRequest

Returns the content type of the GData response.

Specified by:

getResponseContentType in interface Service.GDataRequest

Returns:

ContentType the GData response content type or null if no response content.

getResponseHeader

public String getResponseHeader(String headerName)

Description copied from interface: Service.GDataRequest

Returns the value of the specified response header name or null if no response header of this type exists.

Specified by:

getResponseHeader in interface Service.GDataRequest

Parameters:

headerName - name of header

Returns:

header value.

getResponseDateHeader

public DateTime getResponseDateHeader(String headerName)

Description copied from interface: Service.GDataRequest

Returns the value of a header containing a header or null if no response header of this type exists or it could not be parsed as a valid date.

Specified by:

getResponseDateHeader in interface Service.GDataRequest

Parameters:

headerName - name of header

Returns:

header value.

getResponseStream

public InputStream getResponseStream()
                              throws IOException

Description copied from interface: Service.GDataRequest

Returns an input stream that can be used to read response data from the GData service. Returns null if response data cannot be read as an input stream. Use Service.GDataRequest.getParseSource() instead.

The caller is responsible for ensuring that the input stream is properly closed after the response has been read.

Specified by:

getResponseStream in interface Service.GDataRequest

Returns:

InputStream providing access to GData response input stream.

Throws:

IOException - error obtaining the response input stream.

getParseSource

public ParseSource getParseSource()
                           throws IOException

Description copied from interface: Service.GDataRequest

Returns a parse source that can be used to read response data from the GData service. Parse source is an abstraction over input streams, readers, and other forms of input.

The caller is responsible for ensuring that input streams and readers contained in the parse source are properly closed after the response has been read.

Specified by:

getParseSource in interface Service.GDataRequest

Returns:

ParseSource providing access to GData response data.

Throws:

IOException - error obtaining the response data.

getConnection

public HttpURLConnection getConnection()

Returns the URLConnection instance that represents the underlying connection to the GData service that will be used by this request.

Returns:

connection to GData service.

end

public void end()

Description copied from interface: Service.GDataRequest

Ends all processing associated with this request and releases any transient resources (such as open data streams) required for execution.

Specified by:

end in interface Service.GDataRequest