org.mortbay.servlet
Class GzipFilter

java.lang.Object
  org.mortbay.servlet.UserAgentFilter
      org.mortbay.servlet.GzipFilter

All Implemented Interfaces:

Filter

Direct Known Subclasses:

IncludableGzipFilter

public class GzipFilter
extends UserAgentFilter

GZIP Filter This filter will gzip the content of a response iff:

• The filter is mapped to a matching path
• The response status code is >=200 and <300
• The content length is unknown or more than the minGzipSize initParameter or the minGzipSize is 0(default)
• The content-type is in the coma separated list of mimeTypes set in the mimeTypes initParameter or if no mimeTypes are defined the content-type is not "application/gzip"
• No content-encoding is specified by the resource

Compressing the content can greatly improve the network bandwidth usage, but at a cost of memory and CPU cycles. If this filter is mapped for static content, then use of efficient direct NIO may be prevented, thus use of the gzip mechanism of the DefaultServlet is advised instead.

This filter extends UserAgentFilter and if the the initParameter excludedAgents is set to a comma separated list of user agents, then these agents will be excluded from gzip content.

Author:

gregw

Nested Class Summary

class	GzipFilter.GZIPResponseWrapper
static class	GzipFilter.GzipStream

Field Summary

protected int	_bufferSize
protected Set	_excluded
protected Set	_mimeTypes
protected int	_minGzipSize

Constructor Summary

GzipFilter()

Method Summary

void	destroy()
void	doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
void	init(FilterConfig filterConfig)
protected GzipFilter.GZIPResponseWrapper	newGZIPResponseWrapper(HttpServletRequest request, HttpServletResponse response)

Methods inherited from class org.mortbay.servlet.UserAgentFilter

getUserAgent, getUserAgent

Methods inherited from class java.lang.Object

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

Field Detail

_mimeTypes

protected Set _mimeTypes

_bufferSize

protected int _bufferSize

_minGzipSize

protected int _minGzipSize

_excluded

protected Set _excluded

Constructor Detail

GzipFilter

public GzipFilter()

Method Detail

init

public void init(FilterConfig filterConfig)
          throws ServletException

Specified by:

init in interface Filter

Overrides:

init in class UserAgentFilter

Throws:

ServletException

destroy

public void destroy()

Specified by:

destroy in interface Filter

Overrides:

destroy in class UserAgentFilter

doFilter

public void doFilter(ServletRequest req,
                     ServletResponse res,
                     FilterChain chain)
              throws IOException,
                     ServletException

Specified by:

doFilter in interface Filter

Overrides:

doFilter in class UserAgentFilter

Throws:

IOException

ServletException

newGZIPResponseWrapper

protected GzipFilter.GZIPResponseWrapper newGZIPResponseWrapper(HttpServletRequest request,
                                                                HttpServletResponse response)