001 //======================================================================== 002 //Copyright 2006 Mort Bay Consulting Pty. Ltd. 003 //------------------------------------------------------------------------ 004 //Licensed under the Apache License, Version 2.0 (the "License"); 005 //you may not use this file except in compliance with the License. 006 //You may obtain a copy of the License at 007 //http://www.apache.org/licenses/LICENSE-2.0 008 //Unless required by applicable law or agreed to in writing, software 009 //distributed under the License is distributed on an "AS IS" BASIS, 010 //WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 011 //See the License for the specific language governing permissions and 012 //limitations under the License. 013 //======================================================================== 014 015 package org.apache.activemq.web; 016 017 import java.io.ByteArrayOutputStream; 018 import java.io.IOException; 019 import java.io.InputStream; 020 import java.net.URL; 021 import java.util.HashMap; 022 import java.util.Map; 023 024 import javax.servlet.ServletException; 025 import javax.servlet.http.HttpServletRequest; 026 import javax.servlet.http.HttpServletResponse; 027 028 /* ------------------------------------------------------------ */ 029 /** 030 * AjaxServlet. The AjaxServlet extends the {@link MessageListenerServlet} with 031 * the capability to server the <code>amq.js</code> script and associated 032 * scripts from resources within the activemq-web jar. The amq.js script is the 033 * client side companion to the MessageListenerServlet and supports sending 034 * messages and long polling for receiving messages (Also called Comet style 035 * Ajax). 036 */ 037 public class AjaxServlet extends MessageListenerServlet { 038 039 private Map<String, byte[]> jsCache = new HashMap<String, byte[]>(); 040 private long jsLastModified = 1000 * (System.currentTimeMillis() / 1000); 041 042 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 043 if (request.getPathInfo() != null && request.getPathInfo().endsWith(".js")) { 044 doJavaScript(request, response); 045 } else { 046 super.doGet(request, response); 047 } 048 } 049 050 protected void doJavaScript(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { 051 052 // Look for a local resource first. 053 String js = request.getServletPath() + request.getPathInfo(); 054 URL url = getServletContext().getResource(js); 055 if (url != null) { 056 getServletContext().getNamedDispatcher("default").forward(request, response); 057 return; 058 } 059 060 // Serve from the classpath resources 061 String resource = "org/apache/activemq/web" + request.getPathInfo(); 062 synchronized (jsCache) { 063 064 byte[] data = jsCache.get(resource); 065 if (data == null) { 066 InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource); 067 if (in != null) { 068 ByteArrayOutputStream out = new ByteArrayOutputStream(); 069 byte[] buf = new byte[4096]; 070 int len = in.read(buf); 071 while (len >= 0) { 072 out.write(buf, 0, len); 073 len = in.read(buf); 074 } 075 in.close(); 076 out.close(); 077 data = out.toByteArray(); 078 jsCache.put(resource, data); 079 } 080 } 081 082 if (data != null) { 083 084 long ifModified = request.getDateHeader("If-Modified-Since"); 085 086 if (ifModified == jsLastModified) { 087 response.sendError(HttpServletResponse.SC_NOT_MODIFIED); 088 } else { 089 response.setContentType("application/x-javascript"); 090 response.setContentLength(data.length); 091 response.setDateHeader("Last-Modified", jsLastModified); 092 response.getOutputStream().write(data); 093 } 094 } else { 095 response.sendError(HttpServletResponse.SC_NOT_FOUND); 096 } 097 } 098 } 099 }