org.acegisecurity.util
Class FilterToBeanProxy

java.lang.Object
  org.acegisecurity.util.FilterToBeanProxy

All Implemented Interfaces:

javax.servlet.Filter

public class FilterToBeanProxy
extends Object
implements javax.servlet.Filter

Delegates Filter requests to a Spring-managed bean.

This class acts as a proxy on behalf of a target Filter that is defined in the Spring bean context. It is necessary to specify which target Filter should be proxied as a filter initialization parameter.

On filter initialisation, the class will use Spring's WebApplicationContextUtils.getWebApplicationContext(ServletContext sc) method to obtain an ApplicationContext instance. It will expect to find the target Filter in this ApplicationContext.

To use this filter, it is necessary to specify one of the following filter initialization parameters:

• targetClass indicates the class of the target Filter defined in the bean context. The only requirements are that this target class implements the javax.servlet.Filter interface and at least one instance is available in the ApplicationContext.
• targetBean indicates the bean name of the target class.

If both initialization parameters are specified, targetBean takes priority.

An additional initialization parameter, init, is also supported. If set to "lazy" the initialization will take place on the first HTTP request, rather than at filter creation time. This makes it possible to use FilterToBeanProxy with the Spring ContextLoaderServlet. Where possible you should not use this initialization parameter, instead using ContextLoaderListener.

A final optional initialization parameter, lifecycle, determines whether the servlet container or the IoC container manages the lifecycle of the proxied filter. When possible you should write your filters to be managed via the IoC container interfaces such as InitializingBean and DisposableBean. If you cannot control the filters you wish to proxy (eg you do not have their source code) you might need to allow the servlet container to manage lifecycle via the Filter.init(javax.servlet.FilterConfig) and Filter.destroy() methods. If this case, set the lifecycle initialization parameter to servlet-container-managed. If the parameter is any other value, servlet container lifecycle methods will not be delegated through to the proxy.

Version:

$Id: FilterToBeanProxy.java,v 1.9 2005/11/17 00:56:09 benalex Exp $

Author:

Ben Alex

Constructor Summary

FilterToBeanProxy()

Method Summary

void	destroy()
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)
protected ApplicationContext	getContext(javax.servlet.FilterConfig filterConfig) Allows test cases to override where application context obtained from.
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

FilterToBeanProxy

public FilterToBeanProxy()

Method Detail

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter

doFilter

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

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

init

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

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

getContext

protected ApplicationContext getContext(javax.servlet.FilterConfig filterConfig)

Allows test cases to override where application context obtained from.

Parameters:

filterConfig - which can be used to find the ServletContext

Returns:

the Spring application context