Module org.omnifaces

Package org.omnifaces.filter

Class OnDemandResponseBufferFilter

java.lang.Object

org.omnifaces.filter.HttpFilter

org.omnifaces.filter.OnDemandResponseBufferFilter

All Implemented Interfaces:

Filter

public class OnDemandResponseBufferFilter
extends HttpFilter

Filter that wraps the response with one capable of buffering on command.

The response wrapper is additionally make available as a request attribute, so it's always obtainable even if a following filter wraps the response again. By default the response wrapper is in "pass-through" mode, meaning it will do no buffering. Anywhere during the request it can be switched to buffer by setting its passThrough argument to false.

The next call to obtain the response's writer will then provide one that buffers. Do note that any existing writer that has been obtained before passThrough was set to false and is used afterwards, will not automatically start buffering. Only newly obtained writers will buffer from that point on.

If at the end of the request, when this filter resumes control again, the response is still buffering (passThrough is false) its buffer will be automatically flushed to the underlying response. If however the buffer is not empty, but passThrough is true, no such flushing will be done and it's assumed the application has taken care of this.

Since:

1.2

Author:

Arjan Tijms

See Also:

• Cache

Field Summary

Fields

Modifier and Type	Field	Description
static final String	BUFFERED_RESPONSE	The request attribute name under which the buffered response is stored.

Constructor Summary

Constructors

Constructor	Description
OnDemandResponseBufferFilter()

Method Summary

Modifier and Type	Method	Description
void	doFilter(HttpServletRequest request, HttpServletResponse response, HttpSession session, FilterChain chain)	Filter the HTTP request.

Methods inherited from class org.omnifaces.filter.HttpFilter

destroy, doFilter, getFilterConfig, getInitParameter, getServletContext, init, init

Methods inherited from class java.lang.Object

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

Field Details

BUFFERED_RESPONSE

public static final String BUFFERED_RESPONSE

The request attribute name under which the buffered response is stored.

See Also:

• Constant Field Values

Constructor Details

OnDemandResponseBufferFilter

public OnDemandResponseBufferFilter()

Method Details

doFilter

public void doFilter(HttpServletRequest request,
 HttpServletResponse response,
 HttpSession session,
 FilterChain chain)
              throws ServletException,
IOException

Description copied from class: HttpFilter

Filter the HTTP request. The session argument is null if there is no session.

Specified by:

doFilter in class HttpFilter

Parameters:

request - The HTTP request.

response - The HTTP response.

session - The HTTP session, if any, else null.

chain - The filter chain to continue.

Throws:

ServletException - As wrapper exception when something fails in the request processing.

IOException - Whenever something fails at I/O level.

See Also:

• Filter.doFilter(ServletRequest, ServletResponse, FilterChain)