com.pagecrumb.proxy.ProxyFilter.java Source code

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Here is the source code for com.pagecrumb.proxy.ProxyFilter.java

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/**
 *    
 * Copyright 2013
 *
 * 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 com.pagecrumb.proxy;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.pagecrumb.proxy.util.filter.GenericResponseWrapper;

/**
 * 
 * Filter to identify whether the response needs to be "transformed"
 * i.e., whether to parse and modify URLs from the HTML that is 
 * returned
 * 
 * @author Kerby Martino
 *
 */
public class ProxyFilter implements Filter {

    // TODO: must pass the requested domain URL and pass 
    // down to the re-write parser
    protected final Log log = LogFactory.getLog(getClass());
    private FilterConfig config = null;

    @Override
    public void destroy() {
        this.config = null;
    }

    /**
     * TODO Add hander for null baseURL 
     * @param ServletRequest servletrequest - request from client
     * @param ervletResponse servletresponse - response from server
     */
    @Override
    public void doFilter(ServletRequest servletrequest, final ServletResponse servletresponse, FilterChain chain)
            throws IOException, ServletException {
        log.info("Before invoking chain");
        try {
            String baseURL = ((HttpServletRequest) servletrequest).getQueryString();
            if (baseURL != null) {
                log.info(this.getClass().toString() + " " + "Requested URL: " + baseURL);

                // TODO Must not pass request to .css or .ico etc. to the GenericResponseWrapper
                // Must use regex here, every thing that ends with ".*" must not be passed except

                //if (baseURL.matches(".*?\\.css.*")) {
                //   GenericResponseWrapper responseWrapper 
                //      = new GenericResponseWrapper((HttpServletResponse) servletresponse, baseURL, "css");   
                //   chain.doFilter(servletrequest, responseWrapper);
                //}
                if (baseURL.matches(".*?\\.png.*") || baseURL.matches(".*?\\.ico.*")
                        || baseURL.matches(".*?\\.gif.*") || baseURL.matches(".*?\\.jpeg.*")
                        || baseURL.matches(".*?\\.jpg.*") || baseURL.matches(".*?\\.js.*")) { // Do not process Javascript for now 
                    // Pass the wrapper on to the next filter or servlet
                    log.info("Bypassing Parser - Just do Filter");
                    chain.doFilter(servletrequest, servletresponse);
                } else {
                    String gwtModuleBase = (String) servletrequest.getAttribute("X-GWT-Module-Base");
                    log.info("Module-Base: " + gwtModuleBase);
                    GenericResponseWrapper responseWrapper = new GenericResponseWrapper(
                            (HttpServletResponse) servletresponse, baseURL);
                    chain.doFilter(servletrequest, responseWrapper);
                    log.info("Content type was " + responseWrapper.getContentType());
                }
            } else {
                PrintWriter pw = servletresponse.getWriter();
                pw.println("<html><body><p>Oops, query URL is missing.</p></body></html>");
            }
        } catch (ServletException e) {
            log.error("Caught Servlet Exception");
            Throwable rootCause = e.getRootCause();
            log.error("Root cause is " + rootCause.toString());
            if (rootCause instanceof RuntimeException) { // This is true for any FacesException.
                log.error("Rethrowing exception as RuntimeException" + rootCause.toString());
                throw (RuntimeException) rootCause; // Throw wrapped RuntimeException instead of ServletException.
            } else {
                throw e;
            }
        }
        log.info("After invoking chain");
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        this.config = filterConfig;
        log.info("Logger initiated in " + log.getClass().getName());
    }
}