com.googlecode.android_scripting.facade.EventServer.java Source code

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Here is the source code for com.googlecode.android_scripting.facade.EventServer.java

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/*
 * Copyright (C) 2001 Naranjo Manuel Francisco <manuel@aircable.net>
 *
 * 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 com.googlecode.android_scripting.facade;

import com.googlecode.android_scripting.Log;
import com.googlecode.android_scripting.SimpleServer;
import com.googlecode.android_scripting.event.Event;
import com.googlecode.android_scripting.jsonrpc.JsonBuilder;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.Vector;
import java.util.concurrent.CountDownLatch;

import org.json.JSONException;

/**
 * An Event Forwarding server that forwards events from the rpc queue in realtime to listener
 * clients.
 * 
 * @author Manuel Naranjo (manuel@aircable.net)
 * @see com.googlecode.android_scripting.SimpleServer
 */
public class EventServer extends SimpleServer implements EventFacade.EventObserver {
    private static final Vector<Listener> mListeners = new Vector<Listener>();
    private InetSocketAddress address = null;

    public EventServer() {
        this(0);
    }

    public EventServer(int port) {
        address = startAllInterfaces(port);
    }

    public InetSocketAddress getAddress() {
        return address;
    }

    @Override
    public void shutdown() {
        onEventReceived(new Event("sl4a", "{\"shutdown\": \"event-server\"}"));
        for (Listener listener : mListeners) {
            mListeners.remove(listener);
            listener.lock.countDown();
        }
        super.shutdown();
    }

    @Override
    protected void handleConnection(Socket socket) throws IOException {
        Listener l = new Listener(socket);
        Log.v("Adding EventServer listener " + socket.getPort());
        mListeners.add(l);
        // we are running in the socket accept thread
        // wait until the event dispatcher gets us the events
        // or we die, what ever happens first
        try {
            l.lock.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        try {
            l.sock.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.v("Ending EventServer listener " + socket.getPort());
    }

    public void onEventReceived(Event event) {
        Object result = null;
        try {
            result = JsonBuilder.build(event);
        } catch (JSONException e) {
            return;
        }

        Log.v("EventServer dispatching " + result);

        for (Listener listener : mListeners) {
            if (!listener.out.checkError()) {
                listener.out.write(result + "\n");
                listener.out.flush();
            } else {
                // let the socket accept thread we're done
                mListeners.remove(listener);
                listener.lock.countDown();
            }
        }
    }

    private class Listener {
        private Socket sock;
        private PrintWriter out;
        private CountDownLatch lock = new CountDownLatch(1);

        public Listener(Socket l) throws IOException {
            sock = l;
            out = new PrintWriter(l.getOutputStream(), true);
        }
    }
}