org.cloudfoundry.caldecott.client.TunnelAcceptor.java Source code

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Here is the source code for org.cloudfoundry.caldecott.client.TunnelAcceptor.java

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/*
 * Copyright 2009-2012 the original author or authors.
 *
 * 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.cloudfoundry.caldecott.client;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.cloudfoundry.caldecott.TunnelException;
import org.springframework.core.task.TaskExecutor;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.util.Observable;
import java.util.Observer;
import java.util.concurrent.ConcurrentHashMap;

/**
 * The class responsible for listening for client connection attempts and handing off to
 * a TunnelHandler for handling the actual tunneling communications.
 *
 * @author Thomas Risberg
 */
public class TunnelAcceptor implements Runnable {

    public static final int SOCKET_TIMEOUT = 10000;

    protected final Log logger = LogFactory.getLog(getClass());

    // configuration options
    private final TunnelFactory tunnelFactory;
    private final ServerSocket serverSocket;
    private final TaskExecutor taskExecutor;

    // variable to keep acceptor active
    // this is volatile since it can we altered by another thread via stop()
    private volatile boolean keepGoing = true;

    // concurrent map to keep track of handlers, will be modified from handler threads
    private ConcurrentHashMap<TunnelHandler, Boolean> handlers = new ConcurrentHashMap<TunnelHandler, Boolean>();

    public TunnelAcceptor(ServerSocket serverSocket, TunnelFactory tunnelFactory, TaskExecutor taskExecutor) {
        this.serverSocket = serverSocket;
        this.tunnelFactory = tunnelFactory;
        this.taskExecutor = taskExecutor;
        try {
            this.serverSocket.setSoTimeout(SOCKET_TIMEOUT);
        } catch (SocketException ignore) {
        }
    }

    public void start() {
        logger.info("Starting new acceptor thread: " + this);
        taskExecutor.execute(this);
        logger.debug("Completed start of: " + taskExecutor);
    }

    public boolean isActive() {
        if (handlers.size() > 0) {
            return true;
        } else {
            return false;
        }
    }

    public void stop() {
        logger.info("Stop requested for: " + this);
        keepGoing = false;
    }

    public void run() {
        while (keepGoing) {
            try {
                logger.trace("Waiting for client connection");
                Socket sourceSocket = serverSocket.accept();
                logger.debug("Accepted client connection");
                TunnelHandler handler = new TunnelHandler(sourceSocket, tunnelFactory, taskExecutor);
                handler.addObserver(new Observer() {
                    public void update(Observable observable, Object o) {
                        if (logger.isDebugEnabled()) {
                            logger.debug("Notified that " + observable + " is now " + o);
                        }
                        handlers.remove(observable);
                    }
                });
                handlers.put(handler, true);
                handler.start();
            } catch (SocketTimeoutException ste) {
            } catch (IOException e) {
                if (!keepGoing && serverSocket.isClosed()) {
                    // time to quit so we can ignore this exception
                } else {
                    throw new TunnelException("Error while accepting connections", e);
                }
            }
        }
        if (!handlers.isEmpty()) {
            while (!handlers.isEmpty()) {
                logger.debug("Waiting for " + handlers.size() + " client connections to close");
                for (TunnelHandler handler : handlers.keySet()) {
                    logger.debug("Poking " + handler);
                    handler.poke();
                }
                try {
                    Thread.sleep(10000);
                } catch (InterruptedException ignore) {
                }
            }
        }
        logger.info("Completed acceptor thread for: " + this);
    }
}