hudson
Class ResponseHeaderFilter

java.lang.Object
  hudson.ResponseHeaderFilter

All Implemented Interfaces:

javax.servlet.Filter

public class ResponseHeaderFilter
extends Object
implements javax.servlet.Filter

This filter allows you to modify headers set by the container or other servlets that are out of your control. The particular headers you wish to change are configured in web.xml.

One particular header you you may wish to deal with is "Cache-Control: no-cache" This is a problem with Tomcat when security is used. Continue reading for further details.

If a web app has a <security-constraint> in its web.xml, Tomcat will add a Cache-Control header to every file it serves from that location. This header will prevent browsers from caching the file locally and this drastically slows down Hudson page load times.

To enable this filter, edit the web.xml file to include:

 <filter>
                <filter-name>change-headers-filter</filter-name>
                <filter-class>hudson.ResponseHeaderFilter</filter-class>
                <init-param>
                        <param-name>Pragma</param-name>
                        <param-value>public</param-value>
                </init-param>
                <init-param>
                        <param-name>Cache-Control</param-name>
                        <param-value>max-age=86400, public</param-value>
                </init-param>
 </filter>
 
 And down below that:
 
 <filter-mapping>
                <filter-name>Headers</filter-name>
                <url-pattern>/*</url-pattern>
 </filter-mapping>
 

In the case of the tomcat cache problem, it is important that the url-pattern for the filter matches the url-pattern set for the security-constraint.

Author:

Mike Wille

Constructor Summary

ResponseHeaderFilter()

Method Summary

void	destroy()
void	doFilter(javax.servlet.ServletRequest req, javax.servlet.ServletResponse resp, javax.servlet.FilterChain chain)
void	init(javax.servlet.FilterConfig filterConfig)

Methods inherited from class java.lang.Object

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

Constructor Detail

ResponseHeaderFilter

public ResponseHeaderFilter()

Method Detail

init

public void init(javax.servlet.FilterConfig filterConfig)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

doFilter

public void doFilter(javax.servlet.ServletRequest req,
                     javax.servlet.ServletResponse resp,
                     javax.servlet.FilterChain chain)
              throws IOException,
                     javax.servlet.ServletException

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter