org.chwf.servlet.engine
Class InvokerFilter

java.lang.Object
  |
  +--org.chwf.servlet.filter.FilterSupport
        |
        +--org.chwf.servlet.engine.InvokerFilter

All Implemented Interfaces:

javax.servlet.Filter

public class InvokerFilter

extends FilterSupport

A filter that invokes a controller, and stores the InvocationContext in the request for post-processing.

Author:

Paul Strack

Constructor Summary

InvokerFilter()

Method Summary

void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) Process filter.
static InvocationContext	getContext(javax.servlet.ServletRequest request) Retrieve the invocation context from the request.

Methods inherited from class org.chwf.servlet.filter.FilterSupport

destroy, doHttpFilter, getConfig, init

Methods inherited from class java.lang.Object

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

Constructor Detail

InvokerFilter

public InvokerFilter()

Method Detail

getContext

public static InvocationContext getContext(javax.servlet.ServletRequest request)

Retrieve the invocation context from the request. This method is only valid after the controller has been invoked. In particular, this method can only be used during post-processing in other filters:

 public void doFilter(...) {
   // Should not call getContext() for pre-processing.
   chain.doFilter(request, response);
   // Valid to call getContext() for post-processing.
   InvocationContext context = InvokerFilter.getContext(request);
   // Work with context ...
 }

Parameters:

request - The request.

Returns:

The context, or null if it has not been initialized.

doFilter

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

Process filter.

Overrides:

doFilter in class FilterSupport

Parameters:

request - The request.

response - The response.

chain - The filter chain.

Throws:

javax.servlet.ServletException - For servlet exceptions.

java.io.IOException - For IO exceptions.