clientconnection.java

Massively Multiplayer Space Trading and Combat game. This is an online strategy game, not a 3D space

/*
 * ClientConnection.java
 *
 * Copyright (C) 2000 Jason M. Hanley
 * Released under the GNU General Public License (GPL)
 * See license.txt for additional information.
 *
 * Created on July 23, 2000, 12:08 PM
 */
 
package fate.network;

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

import fate.messages.*;
import fate.util.*;

/** 
 * Attempts to create a network connection between client and server.
 * <br><br>
 * After calling {@link connect(LoginMessage)}, on sucessful connection with
 * the server, this will spawn a new ClientThread to handle incoming messages.
 * Messages will be stored in the {@link messageBuffer} and can be retrieved
 * sequentially using {@link messagesAvailable()} and {@link nextMessage()}.
 *
 * @author  [e-mail]
 * @version 0.1.0
 */
public class ClientConnection extends Object {
  
  LinkedList messageBuffer;
  Socket socket;
  ObjectInputStream in;
  ObjectOutputStream out;
  String host;
  int port;

  /** Creates new ClientConnection */
  public ClientConnection( String host, int port ) {
    this.host = host;
    this.port = port;
    messageBuffer = new LinkedList();
  }
  
  /** Opens a connection to the server */
  public boolean connect( LoginMessage loginMessage )
      throws UnknownHostException, IOException {
        
    // Open up the connection to the server using TCP/IP
    Debug.trace( "ClientConnection opening socket" );
    socket = new Socket( host, port );
    Debug.trace( "ClientConnection creating output stream" );
    out = new ObjectOutputStream( socket.getOutputStream() );
    
    // Send the username and password to the server
    Debug.trace( "ClientConnection sending username/password" );
    out.writeObject( loginMessage );
    
    Debug.trace( "ClientConnection creating input stream" );
    in = new ObjectInputStream( socket.getInputStream() );
    
    LoginMessage loginReturned;
    try {
      Debug.trace( "ClientConnection waiting for server response" );
      loginReturned = (LoginMessage) in.readObject();
    } catch (ClassNotFoundException e) {
      // This is not good
      Debug.trace( "ERROR: ClientConnection.connect(): Class not found" );      
      //@ TODO: error handling
      return false;
    }
    
    // If this was a new user request
    if (loginMessage.username.equals( "(newuser)" ) ) {
      loginMessage.username = loginReturned.username;
      loginMessage.password = loginReturned.password;

      return true;
    }
    
    if (loginReturned.bAccepted)
    {
      Debug.trace( "ClientConnection: Password was accepted" );
      // We're authenticated, so spawn off a client thread to start giving messages
      ClientThread thread = new ClientThread( this, in );
      thread.start();
      return true;
    }
    else
    {
      Debug.trace( "ClientConnection: Invalid password" );
      // No connection established -- bad username or password
      return false;
    }
  }
  
  /** Sends a message to the server */
  public void sendMessage( GameMessage msg ) {
    try {
      out.writeObject( msg );
    } catch( IOException e ) {
      Debug.trace( "ClientConnection.sendMessage: Exception" );
      e.printStackTrace();
    }
  }
  
  /** Called by the communications thread to receive a message */
  public synchronized void receiveMessage( Object msg ) throws IOException {
    Class c = msg.getClass();
    String strClass = c.getName();
    Debug.trace( "ClientConnection received a message: " + strClass );
    messageBuffer.addLast( msg );
  }
  
  /** Returns true if there are messages in the message buffer */
  public boolean messagesAvailable() {
    return ( messageBuffer.size() > 0 );
  }
  
  /** Returns the next message in the buffer, or NULL is there are none.
      Should check with messagesAvailable first to see if there are any */
  public synchronized Object nextMessage() {
    return ( messageBuffer.removeFirst() );
  }
}