org.onlab.stc.MonitorWebSocketServlet Maven / Gradle / Ivy
/*
* Copyright 2015-present Open Networking Laboratory
*
* 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.onlab.stc;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.common.io.ByteStreams;
import com.google.common.net.MediaType;
import org.eclipse.jetty.websocket.WebSocket;
import org.eclipse.jetty.websocket.WebSocketServlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.Timer;
import java.util.TimerTask;
/**
* Web socket servlet capable of creating web sockets for the STC monitor.
*/
public class MonitorWebSocketServlet extends WebSocketServlet
implements MonitorDelegate {
private static final long PING_DELAY_MS = 5000;
private static final String DOT = ".";
private static Monitor monitor;
private static MonitorWebSocketServlet instance;
private final Set sockets = new HashSet<>();
private final Timer timer = new Timer();
private final TimerTask pruner = new Pruner();
/**
* Binds the shared process flow monitor.
*
* @param m process monitor reference
*/
public static void setMonitor(Monitor m) {
monitor = m;
}
/**
* Closes all currently open monitor web-sockets.
*/
public static void closeAll() {
if (instance != null) {
instance.sockets.forEach(MonitorWebSocket::close);
instance.sockets.clear();
}
}
@Override
public void init() throws ServletException {
super.init();
instance = this;
monitor.setDelegate(this);
timer.schedule(pruner, PING_DELAY_MS, PING_DELAY_MS);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String uri = req.getRequestURI();
uri = uri.length() <= 1 ? "/index.html" : uri;
InputStream resource = getClass().getResourceAsStream(uri);
if (resource == null) {
resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
} else {
byte[] entity = ByteStreams.toByteArray(resource);
resp.setStatus(HttpServletResponse.SC_OK);
resp.setContentType(contentType(uri).toString());
resp.setContentLength(entity.length);
resp.getOutputStream().write(entity);
}
}
private MediaType contentType(String uri) {
int sep = uri.lastIndexOf(DOT);
String ext = sep > 0 ? uri.substring(sep + 1) : null;
return ext == null ? MediaType.APPLICATION_BINARY :
ext.equals("html") ? MediaType.HTML_UTF_8 :
ext.equals("js") ? MediaType.JAVASCRIPT_UTF_8 :
ext.equals("css") ? MediaType.CSS_UTF_8 :
MediaType.APPLICATION_BINARY;
}
@Override
public WebSocket doWebSocketConnect(HttpServletRequest request, String protocol) {
MonitorWebSocket socket = new MonitorWebSocket(monitor);
synchronized (sockets) {
sockets.add(socket);
}
return socket;
}
@Override
public void notify(ObjectNode event) {
if (instance != null) {
instance.sockets.forEach(ws -> ws.sendMessage(event));
}
}
// Task for pruning web-sockets that are idle.
private class Pruner extends TimerTask {
@Override
public void run() {
synchronized (sockets) {
Iterator it = sockets.iterator();
while (it.hasNext()) {
MonitorWebSocket socket = it.next();
if (socket.isIdle()) {
it.remove();
socket.close();
}
}
}
}
}
}