threadedechoserver.java

servlet与jsp核心编程 书籍源码 部分

import java.net.*;
import java.io.*;

/** A multithreaded variation of EchoServer.
 *  <P>
 *  Taken from Core Servlets and JavaServer Pages
 *  from Prentice Hall and Sun Microsystems Press,
 *  http://www.coreservlets.com/.
 *  &copy; 2000 Marty Hall; may be freely used or adapted.
 */

public class ThreadedEchoServer extends EchoServer
                                implements Runnable {
  public static void main(String[] args) {
    int port = 8088;
    if (args.length > 0) {
      try {
        port = Integer.parseInt(args[0]);
      } catch(NumberFormatException nfe) {}
    }
    ThreadedEchoServer echoServer =
      new ThreadedEchoServer(port, 0);
    echoServer.serverName = "Threaded EchoServer";
  }

  public ThreadedEchoServer(int port, int connections) {
    super(port, connections);
  }

  /** The new version of handleConnection starts
   *  a thread. This new thread will call back to the
   *  <I>old</I> version of handleConnection, resulting
   *  in the same server behavior in a multithreaded
   *  version. The thread stores the Socket instance
   *  since run doesn't take any arguments, and since
   *  storing the socket in an instance variable risks
   *  having it overwritten if the next thread starts
   *  before the run method gets a chance to
   *  copy the socket reference.
   */
                                  
  public void handleConnection(Socket server) {
    Connection connectionThread = new Connection(this, server);
    connectionThread.start();
  }
    
  public void run() {
    Connection currentThread =
      (Connection)Thread.currentThread();
    try {
      super.handleConnection(currentThread.serverSocket);
    } catch(IOException ioe) {
      System.out.println("IOException: " + ioe);
      ioe.printStackTrace();
    }
  }
}

/** This is just a Thread with a field to store a
 *  Socket object. Used as a thread-safe means to pass
 *  the Socket from handleConnection to run.
 */

class Connection extends Thread {
  protected Socket serverSocket;

  public Connection(Runnable serverObject,
                    Socket serverSocket) {
    super(serverObject);
    this.serverSocket = serverSocket;
  }
}