ActiveMQ example source code file (RssMessageRenderer.java)

This example ActiveMQ source code file (RssMessageRenderer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

http, httpservletrequest, httpservletrequest, io, ioexception, jmsexception, jmsexception, message, queuebrowser, request, response, servlet, servletexception, string, string, syndcontent, syndentry, syndfeed, syndfeed, util

The ActiveMQ RssMessageRenderer.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.activemq.web.view;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.List;

import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.QueueBrowser;
import javax.jms.TextMessage;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.sun.syndication.feed.synd.SyndContent;
import com.sun.syndication.feed.synd.SyndContentImpl;
import com.sun.syndication.feed.synd.SyndEntry;
import com.sun.syndication.feed.synd.SyndEntryImpl;
import com.sun.syndication.feed.synd.SyndFeed;
import com.sun.syndication.feed.synd.SyndFeedImpl;
import com.sun.syndication.io.FeedException;
import com.sun.syndication.io.SyndFeedOutput;

/**
 * This renderer uses XStream to render messages on a queue as full XML elements
 * 
 * 
 */
public class RssMessageRenderer extends SimpleMessageRenderer {

    // private String feedType = "atom_0.3";
    private String feedType = "rss_2.0";
    private SyndFeed feed;
    private String description = "This feed is auto-generated by Apache ActiveMQ";
    private String entryContentType = "text/plain";

    public void renderMessage(PrintWriter writer, HttpServletRequest request, HttpServletResponse response, QueueBrowser browser, Message message) throws JMSException {
        SyndFeed feed = getFeed(browser, request);

        List<SyndEntry> entries = feed.getEntries();
        SyndEntry entry = createEntry(browser, message, request);
        SyndContent description = createEntryContent(browser, message, request);
        entry.setDescription(description);
        entries.add(entry);
    }

    // Properties
    // -------------------------------------------------------------------------
    public String getDescription() {
        return description;
    }

    public void setDescription(String feedDescription) {
        this.description = feedDescription;
    }

    public String getFeedType() {
        return feedType;
    }

    public void setFeedType(String feedType) {
        this.feedType = feedType;
    }

    public String getEntryContentType() {
        return entryContentType;
    }

    public void setEntryContentType(String entryContentType) {
        this.entryContentType = entryContentType;
    }

    // Implementation methods
    // -------------------------------------------------------------------------

    protected void printFooter(PrintWriter writer, QueueBrowser browser, HttpServletRequest request) throws IOException, JMSException, ServletException {
        // now lets actually write out the content
        SyndFeed feed = getFeed(browser, request);
        SyndFeedOutput output = new SyndFeedOutput();
        try {
            output.output(feed, writer);
        } catch (FeedException e) {
            throw new ServletException(e);
        }
    }

    protected void printHeader(PrintWriter writer, QueueBrowser browser, HttpServletRequest request) throws IOException, JMSException {
    }

    public SyndFeed getFeed(QueueBrowser browser, HttpServletRequest request) throws JMSException {
        if (feed == null) {
            feed = createFeed(browser, request);
        }
        return feed;
    }

    protected SyndEntry createEntry(QueueBrowser browser, Message message, HttpServletRequest request) throws JMSException {
        SyndEntry entry = new SyndEntryImpl();
        String title = message.getJMSMessageID();
        entry.setTitle(title);
        String link = request.getRequestURI() + "?msgId=" + title;
        entry.setLink(link);
        entry.setPublishedDate(new Date());
        return entry;
    }

    protected SyndContent createEntryContent(QueueBrowser browser, Message message, HttpServletRequest request) throws JMSException {
        SyndContent description = new SyndContentImpl();
        description.setType(entryContentType);

        if (message instanceof TextMessage) {
            String text = ((TextMessage)message).getText();
            description.setValue(text);
        }
        return description;
    }

    protected SyndFeed createFeed(QueueBrowser browser, HttpServletRequest request) throws JMSException {
        SyndFeed feed = new SyndFeedImpl();
        feed.setFeedType(feedType);

        String title = browser.getQueue().toString();
        String selector = browser.getMessageSelector();
        if (selector != null) {
            title += " with selector: " + selector;
        }
        feed.setTitle(title);
        feed.setLink(request.getRequestURI());
        feed.setDescription(getDescription());
        return feed;
    }

}