de.xwic.appkit.core.cluster.impl.ClientHandler.java Source code

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Here is the source code for de.xwic.appkit.core.cluster.impl.ClientHandler.java

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/*******************************************************************************
 * Copyright 2015 xWic group (http://www.xwic.de)
 *
 * 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 de.xwic.appkit.core.cluster.impl;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import de.xwic.appkit.core.cluster.ICommProtocol;
import de.xwic.appkit.core.cluster.Message;
import de.xwic.appkit.core.cluster.Response;

/**
 * Handles an incoming connection.
 * 
 * @author lippisch
 *
 */
public class ClientHandler implements Runnable {

    private final Log log = LogFactory.getLog(getClass());

    private Socket socket;
    private ICommProtocol protocol = null;

    private Cluster cluster;

    /**
     * @param socket
     */
    public ClientHandler(Cluster cluster, Socket socket) {
        super();
        this.cluster = cluster;
        this.socket = socket;
    }

    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
     */
    @Override
    public void run() {

        try {

            //socket.setSoTimeout(10000); // set the timeout to 10 seconds.

            ObjectInputStream oIn = new ObjectInputStream(socket.getInputStream());
            ObjectOutputStream oOut = new ObjectOutputStream(socket.getOutputStream());

            while (true) {
                Message msgIn;
                try {
                    msgIn = (Message) oIn.readObject();
                } catch (IOException e) {
                    // this occurs when the connection is closed
                    log.info("Client " + socket.getInetAddress() + " disconnected.");
                    break;
                } catch (ClassNotFoundException e) {
                    log.error("Can not handle incoming message - stream might be corrupted..", e);
                    break;
                }

                Response response = null;

                //System.out.println("Received: " + msgIn.getCommand() + " ('" + msgIn.getArgument() + "')");

                // as long as the client is not identified, no protocol is selected. 
                if (protocol == null) {
                    if (Message.CMD_IDENTIFY_CLIENT.equals(msgIn.getCommand())) {
                        // argument must contain client type, which causes the selection of the right protocol
                        // hard-coded here right now, but might get externalized into some configuration file
                        // later on...
                        if ("ClusterNode".equals(msgIn.getArgument())) {
                            protocol = new ClusterNodeClientProtocol(cluster);
                        } else if ("Console".equals(msgIn.getArgument())) {
                            protocol = new ConsoleClientProtocol(cluster);
                        } else {
                            log.debug("Invalid protocol selected.");
                            response = new Response(false, "Invalid protocol selected.");
                        }

                        if (protocol != null) {
                            log.info("Selected protocol " + protocol.getClass().getName());
                        }

                    } else {
                        log.debug("Invalid command received - awaiting client identification..");
                    }
                } else {
                    response = protocol.handleMessage(socket, msgIn);
                }

                if (response == null) {
                    response = new Response(true); // send success response
                }

                oOut.writeObject(response);

            }

        } catch (IOException e) {
            log.error("Communication error with client", e);
            // will cause an exit.. 
        }

        if (protocol != null) {
            protocol.onConnectionLost();
        }
        // close the socket.
        try {
            socket.close();
        } catch (IOException e) {
            log.warn("Error closing socket.", e);
        }

        // handle exiting properly (i.e. notify Cluster instance)

    }

}