edu.gmu.isa681.server.Server.java Source code

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Here is the source code for edu.gmu.isa681.server.Server.java

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/*
** Copyright 2013 Mohamed Elsabagh <melsabag@gmu.edu>
**
** This file is part of GoForward. See LICENSE for more details.
*/

package edu.gmu.isa681.server;

import java.io.FileInputStream;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.KeyStore;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLServerSocket;
import javax.net.ssl.SSLServerSocketFactory;
import javax.net.ssl.SSLSocket;

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

import edu.gmu.isa681.server.core.SessionHandler;
import edu.gmu.isa681.util.Utils;

final class Server implements Runnable {
    private Log log = LogFactory.getLog(Server.class);

    private int port;
    private SSLServerSocket sslServerSocket = null;

    private Object shutdownLock = new Object();
    private boolean shuttingDown = false;

    /**
     * Constructs and initializes a server instance. 
     * Note: the server will not run until the {@link #run()} method is called.
     * @param port Port number where the server should listen on for incoming connections.
     */
    public Server(int port) {
        this.port = port;
    }

    /**
     * Establishes the SSL server socket and listens for incoming connections. A stand-alone <code>SessionHandler</code> 
     * is spawned for each connection.
     */
    public void run() {
        try {
            SSLServerSocketFactory ssf = (SSLServerSocketFactory) getSSLServerSocketFactory();

            try {
                sslServerSocket = (SSLServerSocket) ssf.createServerSocket(port);
                log.info("Server started.");

                while (true) {
                    synchronized (shutdownLock) {
                        if (shuttingDown)
                            break;
                    }

                    try {
                        SSLSocket sslSocket = (SSLSocket) sslServerSocket.accept();
                        handleRequest(sslSocket);

                    } catch (IOException ex) {
                        log.error("Exception while handling request.", ex);
                    }
                }
            } catch (IOException ex) {
                log.error(ex.getMessage(), ex);
            }

        } catch (GeneralSecurityException | IOException ex) {
            log.fatal(ex.getMessage(), ex);
        }

        shutdown();
    }

    /**
     * Creates a TLS server socket factory using the key store and key store password provided to the JVM at runtime.
     * @return
     * @throws GeneralSecurityException If an error occurs while creating the TLS factory.
     * @throws IOException If an error occurs while reading the key store.
     * 
     * Adapted from Oracle JSSE docs.
     */
    private static SSLServerSocketFactory getSSLServerSocketFactory() throws GeneralSecurityException, IOException {
        FileInputStream fis = null;
        try {
            SSLServerSocketFactory ssf = null;
            // set up key manager to do server authentication
            SSLContext ctx = SSLContext.getInstance("TLS");
            KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
            KeyStore ks = KeyStore.getInstance("JKS");

            String keyStore = System.getProperty("javax.net.ssl.keyStore");
            String keyStorePassword = System.getProperty("javax.net.ssl.keyStorePassword");

            fis = new FileInputStream(keyStore);
            ks.load(fis, keyStorePassword.toCharArray());

            kmf.init(ks, keyStorePassword.toCharArray());
            ctx.init(kmf.getKeyManagers(), null, null);

            ssf = ctx.getServerSocketFactory();
            return ssf;

        } finally {
            Utils.closeQuitely(fis);
        }
    }

    /**
     * Shuts the server down and closes the server SSL socket. Calling <code>shutdown()</code> more than 
     * once has no effect.
     */
    public void shutdown() {
        synchronized (shutdownLock) {
            if (shuttingDown)
                return;

            log.info("Shutting down...");
            shuttingDown = true;
            Utils.closeQuitely(sslServerSocket);
        }
    }

    /**
     * Spawns a <code>SessionHandler</code> for the given SSL connection.
     * @param sslSocket
     */
    private void handleRequest(SSLSocket sslSocket) {
        SessionHandler handler = new SessionHandler(sslSocket);
        Thread thread = new Thread(handler, "RequestHandler[" + sslSocket.getInetAddress().toString() + "]");
        thread.setDaemon(true);
        thread.start();
    }
}