org.deegree.services.controller.utils
Class HttpResponseBuffer

java.lang.Object
  javax.servlet.ServletResponseWrapper
      javax.servlet.http.HttpServletResponseWrapper
          org.deegree.services.controller.utils.HttpResponseBuffer

All Implemented Interfaces:

javax.servlet.http.HttpServletResponse, javax.servlet.ServletResponse

public class HttpResponseBuffer
extends javax.servlet.http.HttpServletResponseWrapper

Custom HttpServletResponseWrapper that buffers all written data internally and will only send the result when flushBuffer() is called.

This allows for two things:

• The header can be changed after the response is generated.
• The whole response and the header can be discarded.

With the first the service is able to set the Content-length. The second allows to discard the generated response and start the response from scratch. This is useful if an exception occurred and an ExceptionReport should be returned and not the partial original result.

This wrapper allows the change between getWriter() and getOutputStream() after reset() was called. This is unlike the original servlet API that throws an IllegalStateException when getWriter is called after getOutputStream, or vice versa.

Version:

$Revision: 28744 $, $Date: 2010-12-10 19:53:56 +0100 (Fri, 10 Dec 2010) $

Author:

Rutger Bezema, Oliver Tonnhofer, Markus Schneider, last edited by: $Author: mschneider $

Field Summary

Fields inherited from interface javax.servlet.http.HttpServletResponse

SC_ACCEPTED, SC_BAD_GATEWAY, SC_BAD_REQUEST, SC_CONFLICT, SC_CONTINUE, SC_CREATED, SC_EXPECTATION_FAILED, SC_FORBIDDEN, SC_FOUND, SC_GATEWAY_TIMEOUT, SC_GONE, SC_HTTP_VERSION_NOT_SUPPORTED, SC_INTERNAL_SERVER_ERROR, SC_LENGTH_REQUIRED, SC_METHOD_NOT_ALLOWED, SC_MOVED_PERMANENTLY, SC_MOVED_TEMPORARILY, SC_MULTIPLE_CHOICES, SC_NO_CONTENT, SC_NON_AUTHORITATIVE_INFORMATION, SC_NOT_ACCEPTABLE, SC_NOT_FOUND, SC_NOT_IMPLEMENTED, SC_NOT_MODIFIED, SC_OK, SC_PARTIAL_CONTENT, SC_PAYMENT_REQUIRED, SC_PRECONDITION_FAILED, SC_PROXY_AUTHENTICATION_REQUIRED, SC_REQUEST_ENTITY_TOO_LARGE, SC_REQUEST_TIMEOUT, SC_REQUEST_URI_TOO_LONG, SC_REQUESTED_RANGE_NOT_SATISFIABLE, SC_RESET_CONTENT, SC_SEE_OTHER, SC_SERVICE_UNAVAILABLE, SC_SWITCHING_PROTOCOLS, SC_TEMPORARY_REDIRECT, SC_UNAUTHORIZED, SC_UNSUPPORTED_MEDIA_TYPE, SC_USE_PROXY

Constructor Summary

HttpResponseBuffer(javax.servlet.http.HttpServletResponse response)

Method Summary

void	disableBuffering() Disables the buffering of the output.
void	flushBuffer()
OutputStream	getBuffer()
int	getBufferSize()
javax.servlet.ServletOutputStream	getOutputStream()
javax.servlet.http.HttpServletResponse	getWrappee()
PrintWriter	getWriter()
XMLStreamWriter	getXMLWriter() Returns an XMLStreamWriter for writing a response with XML content.
XMLStreamWriter	getXMLWriter(boolean setCharacterEncoding) Returns an XMLStreamWriter for writing a response with XML content.
void	reset()
void	validate() Performs a schema-based validation of the response (only if the written output has been buffered and was XML).

Methods inherited from class javax.servlet.http.HttpServletResponseWrapper

addCookie, addDateHeader, addHeader, addIntHeader, containsHeader, encodeRedirectUrl, encodeRedirectURL, encodeUrl, encodeURL, sendError, sendError, sendRedirect, setDateHeader, setHeader, setIntHeader, setStatus, setStatus

Methods inherited from class javax.servlet.ServletResponseWrapper

getCharacterEncoding, getContentType, getLocale, getResponse, isCommitted, resetBuffer, setBufferSize, setCharacterEncoding, setContentLength, setContentType, setLocale, setResponse

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.ServletResponse

getCharacterEncoding, getContentType, getLocale, isCommitted, resetBuffer, setBufferSize, setCharacterEncoding, setContentLength, setContentType, setLocale

Constructor Detail

HttpResponseBuffer

public HttpResponseBuffer(javax.servlet.http.HttpServletResponse response)

Parameters:

response -

Method Detail

getWrappee

public javax.servlet.http.HttpServletResponse getWrappee()

Returns:

the underlying servlet response

disableBuffering

public void disableBuffering()

Disables the buffering of the output.

This method may only be called, if neither getWriter(), getOutputStream() nor getXMLWriter() has been called before.

getWriter

public PrintWriter getWriter()
                      throws IOException

Specified by:

getWriter in interface javax.servlet.ServletResponse

Overrides:

getWriter in class javax.servlet.ServletResponseWrapper

Throws:

IOException

getOutputStream

public javax.servlet.ServletOutputStream getOutputStream()
                                                  throws IOException

Specified by:

getOutputStream in interface javax.servlet.ServletResponse

Overrides:

getOutputStream in class javax.servlet.ServletResponseWrapper

Throws:

IOException

getXMLWriter

public XMLStreamWriter getXMLWriter()
                             throws IOException,
                                    XMLStreamException

Returns an XMLStreamWriter for writing a response with XML content.

NOTE: This method may be called more than once -- the first call will create an XMLStreamWriter object and subsequent calls return the same object. This provides a convenient means to produce plain XML responses and SOAP wrapped response bodies with the same code.

Returns:

XMLStreamWriter for writing the response, with XML preamble already written

Throws:

IOException

XMLStreamException

getXMLWriter

public XMLStreamWriter getXMLWriter(boolean setCharacterEncoding)
                             throws IOException,
                                    XMLStreamException

Returns an XMLStreamWriter for writing a response with XML content.

NOTE: This method may be called more than once -- the first call will create an XMLStreamWriter object and subsequent calls return the same object. This provides a convenient means to produce plain XML responses and SOAP wrapped response bodies with the same code.

Parameters:

setCharacterEncoding - true, if the response's character encoding should be set, false otherwise

Returns:

XMLStreamWriter for writing the response, with XML preamble already written

Throws:

IOException

XMLStreamException

validate

public void validate()

Performs a schema-based validation of the response (only if the written output has been buffered and was XML).

flushBuffer

public void flushBuffer()
                 throws IOException

Specified by:

flushBuffer in interface javax.servlet.ServletResponse

Overrides:

flushBuffer in class javax.servlet.ServletResponseWrapper

Throws:

IOException

reset

public void reset()

Specified by:

reset in interface javax.servlet.ServletResponse

Overrides:

reset in class javax.servlet.ServletResponseWrapper

getBufferSize

public int getBufferSize()

Specified by:

getBufferSize in interface javax.servlet.ServletResponse

Overrides:

getBufferSize in class javax.servlet.ServletResponseWrapper

getBuffer

public OutputStream getBuffer()

Returns:

the buffer