//========================================================================
//Copyright 2006 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//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 org.apache.activemq.web;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/* ------------------------------------------------------------ */
/**
* AjaxServlet. The AjaxServlet extends the {@link MessageListenerServlet} with
* the capability to server the <code>amq.js</code> script and associated
* scripts from resources within the activemq-web jar. The amq.js script is the
* client side companion to the MessageListenerServlet and supports sending
* messages and long polling for receiving messages (Also called Comet style
* Ajax).
*/
public class AjaxServlet extends MessageListenerServlet {
private static final long serialVersionUID = -3875280764356406114L;
private Map<String, byte[]> jsCache = new HashMap<String, byte[]>();
private long jsLastModified = 1000 * (System.currentTimeMillis() / 1000);
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
if (request.getPathInfo() != null && request.getPathInfo().endsWith(".js")) {
doJavaScript(request, response);
} else {
super.doGet(request, response);
}
}
protected void doJavaScript(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
// Look for a local resource first.
String js = request.getServletPath() + request.getPathInfo();
URL url = getServletContext().getResource(js);
if (url != null) {
getServletContext().getNamedDispatcher("default").forward(request, response);
return;
}
// Serve from the classpath resources
String resource = "org/apache/activemq/web" + request.getPathInfo();
synchronized (jsCache) {
byte[] data = jsCache.get(resource);
if (data == null) {
try(InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource)) {
if (in != null) {
try(ByteArrayOutputStream out = new ByteArrayOutputStream()) {
byte[] buf = new byte[4096];
int len = in.read(buf);
while (len >= 0) {
out.write(buf, 0, len);
len = in.read(buf);
}
data = out.toByteArray();
jsCache.put(resource, data);
}
}
}
}
if (data != null) {
long ifModified = request.getDateHeader("If-Modified-Since");
if (ifModified == jsLastModified) {
response.sendError(HttpServletResponse.SC_NOT_MODIFIED);
} else {
response.setContentType("application/x-javascript");
response.setContentLength(data.length);
response.setDateHeader("Last-Modified", jsLastModified);
response.getOutputStream().write(data);
}
} else {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
}
}
}
}