permutationsfilter.java

ajax patterns 这是关于ajax设计模式方面的原代码

/*
    Copyright 2006 Christian Gross http://www.devspace.com
    From the book Ajax Patterns and Best Practices

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
package devspace.ajax.permutations;

import devspace.ajax.permutations.implementations.*;
import devspace.testDrivenDevelopment.tracer.*;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

class ResourceFactory {
    public static Collection< ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain>> createRewriters() {
        Collection< ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain>> collection =
            new ArrayList< ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain>>();
        collection.add( new PreConfiguredResource());
        collection.add( new SlashPeriodResource());
        return collection;
    }
}

public class PermutationsFilter implements Filter {
    private FilterConfig _filterConfig;

    Collection< ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain>> _urlRewriters;
    
    public void init(FilterConfig filterConfig) throws ServletException {
        _filterConfig = filterConfig;
        _urlRewriters = ResourceFactory.createRewriters();
        for( ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain> urlrewriter : _urlRewriters) {
            ResourceInitialization< FilterConfig> filter = (ResourceInitialization< FilterConfig>)urlrewriter;
            filter.initialize( filterConfig);
        }
        GenerateOutput.Write( "PermutationsModule.init", "Initialized permutations");
    }
    
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httprequest = (HttpServletRequest)request;
        HttpServletResponse httpresponse = (HttpServletResponse)response;
        GenerateOutput.Write( "PermutationsModule.doFilter",  ">>>> Start");
        for( ResourceRewriter<HttpServletRequest, HttpServletResponse, FilterChain> urlrewriter : _urlRewriters) {
            if( urlrewriter.isResource( httprequest)) {
                GenerateOutput.Write( "PermutationsModule.doFilter", "Is resource and URL will be rewritten");
                urlrewriter.writeRepresentation( httprequest, httpresponse, chain);
                GenerateOutput.Write( "PermutationsModule.doFilter", "<<<< End");
                return;
            }
            else {
                GenerateOutput.Write( "PermutationsModule.doFilter", "Is not resource and URL will not be rewritten");
            }
        }
        GenerateOutput.Write( "PermutationsModule.doFilter", "<<<< End");
        chain.doFilter( request, response);
    }

    public void destroy() {
        // TODO Auto-generated method stub
        
    }

}