org.opennms.web
Class AddRefreshHeaderFilter

java.lang.Object
  org.opennms.web.AddRefreshHeaderFilter

All Implemented Interfaces:

javax.servlet.Filter

public class AddRefreshHeaderFilter

extends java.lang.Object

implements javax.servlet.Filter

A filter that adds an HTTP Refresh header to a servlet or JSP's response. The amount of time to wait before refresh is configurable.

Author:

Lawrence Karnowski, OpenNMS

Field Summary

protected javax.servlet.FilterConfig	filterConfig
protected java.lang.String	seconds

Constructor Summary

AddRefreshHeaderFilter()

Method Summary

void	destroy()
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) Adds a Refresh HTTP header before processing the request.
void	init(javax.servlet.FilterConfig config)

Methods inherited from class java.lang.Object

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

Field Detail

filterConfig

protected javax.servlet.FilterConfig filterConfig

seconds

protected java.lang.String seconds

Constructor Detail

AddRefreshHeaderFilter

public AddRefreshHeaderFilter()

Method Detail

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain chain)
              throws java.io.IOException,
                     javax.servlet.ServletException

Adds a Refresh HTTP header before processing the request.

This is a strange implementation, because intuitively, you would add the header after the content has been produced (in other words, after you had already called FilterChain.doFilter. However, the Servlet 2.3 spec (proposed final draft) states (albeitly in an off-handed fashion) that you can only "examine" the response headers after the doFilter call. Evidently this means that you cannot change the headers after the doFilter. If you call setHeader nothing happens.

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

java.io.IOException

javax.servlet.ServletException

init

public void init(javax.servlet.FilterConfig config)

Specified by:

init in interface javax.servlet.Filter

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter