ca.flop.jpublish.dwr.DWRUrlProcessor.java Source code

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Here is the source code for ca.flop.jpublish.dwr.DWRUrlProcessor.java

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/*
 *
 * Copyright 2007 Florin T.PATRASCU
 *
 * 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 ca.flop.jpublish.dwr;

import com.anthonyeden.lib.config.Configuration;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.Container;
import org.directwebremoting.util.LocalUtil;
import org.directwebremoting.extend.Handler;
import org.directwebremoting.extend.InitializingBean;
import org.directwebremoting.servlet.ExceptionHandler;
import org.directwebremoting.servlet.NotFoundHandler;
import org.directwebremoting.servlet.PathConstants;
import org.jpublish.JPublishContext;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * This is the main servlet that handles all the requests to DWR.
 * <p>It is on the large side because it can't use technologies like JSPs etc
 * since it all needs to be deployed in a single jar file, and while it might be
 * possible to integrate Velocity or similar I think simplicity is more
 * important, and there are only 2 real pages both script heavy in this servlet
 * anyway.</p>
 * <p>There are 5 things to do, in the order that you come across them:</p>
 * <ul>
 * <li>The index test page that points at the classes</li>
 * <li>The class test page that lets you execute methods</li>
 * <li>The interface javascript that uses the engine to send requests</li>
 * <li>The engine javascript to form the iframe request and process replies</li>
 * <li>The exec 'page' that executes the method and returns data to the iframe</li>
 * </ul>
 *
 * @author Joe Walker [joe at getahead dot ltd dot uk]
 * @author <a href="mailto:florin.patrascu@gmail.com">Florin T.PATRASCU</a>
 * @since $Revision$ (created: January 19, 2007)
 */
public class DWRUrlProcessor implements Handler, InitializingBean {
    protected static final Log log = LogFactory.getLog(DWRUrlProcessor.class);

    /**
     * The URL for the {@link org.directwebremoting.servlet.IndexHandler}
     *
     * @param indexHandlerUrl the indexHandlerUrl to set
     */
    public void setIndexHandlerUrl(String indexHandlerUrl) {
        this.indexHandlerUrl = indexHandlerUrl;
    }

    /**
     * The URL for the {@link org.directwebremoting.servlet.IndexHandler}
     */
    private String indexHandlerUrl;

    /**
     * The mapping of URLs to {@link Handler}s
     */
    private Map urlMapping = new HashMap();

    /**
     * The default if we have no other action (HTTP-404)
     */
    private Handler notFoundHandler = new NotFoundHandler();

    /**
     * If execution fails, we do this (HTTP-501)
     */
    private ExceptionHandler exceptionHandler = new ExceptionHandler();

    /* (non-Javadoc)
    * @see org.directwebremoting.InitializingBean#afterPropertiesSet(Container)
    */
    public void afterContainerSetup(Container container) {
        Collection beanNames = container.getBeanNames();
        for (Iterator it = beanNames.iterator(); it.hasNext();) {
            String name = (String) it.next();
            if (name.startsWith(PathConstants.URL_PREFIX)) {
                Object bean = container.getBean(name);

                if (bean instanceof Handler) {
                    urlMapping.put(name.substring(PathConstants.URL_PREFIX.length()), bean);
                } else {
                    log.error("Discarding non Handler for " + name);
                }
            }
        }
    }

    public void handle(HttpServletRequest request, HttpServletResponse response) throws IOException {
        log.info("-Why are you calling me? " + request.getPathInfo());
    }

    /* (non-Javadoc)
    * @see org.directwebremoting.Handler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
    */
    //public void handle(HttpServletRequest request, HttpServletResponse response) throws IOException {
    public void handle(JPublishContext context) throws IOException {
        HttpServletRequest request = context.getRequest();
        HttpServletResponse response = context.getResponse();
        try {
            String pathInfo = LocalUtil.replace(request.getPathInfo(), (String) context.get("dwrPathPrefix"), "");
            //String pathInfo = request.getPathInfo();

            if (pathInfo == null || pathInfo.length() == 0 || pathInfo.equals("/")) {
                response.sendRedirect(request.getContextPath() + request.getServletPath() + indexHandlerUrl);
            } else {
                // Loop through all the known URLs
                for (Iterator it = urlMapping.entrySet().iterator(); it.hasNext();) {
                    Map.Entry entry = (Map.Entry) it.next();
                    String url = (String) entry.getKey();

                    // If this URL matches, call the handler
                    if (pathInfo.startsWith(url)) {
                        Handler handler = (Handler) entry.getValue();
                        handler.handle(request, response);
                        context.setStopProcessing();
                        return;
                    }
                }

                notFoundHandler.handle(request, response);
            }
        } catch (Exception ex) {
            exceptionHandler.setException(ex);
            exceptionHandler.handle(request, response);
        }
    }

    public void handle(JPublishContext context, Configuration configuration) throws IOException {
        this.handle(context);
    }
}