PlayerSocket.java

// PlayerSocket.java
// Copyright (c) 2012 Andrew Downing
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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

/** encapsulates Socket-related classes for a single player */
public class PlayerSocket {
  private Socket socket; /**< client socket that is endpoint for network communication */
  private ObjectInputStream in; /**< reads messages related to this player over the network */
  private ObjectOutputStream out; /**< writes messages related to this player over the network */
  private String playerName; /**< name of player associated with this socket */

  /** constructor for player socket */
  public PlayerSocket(Socket newSocket) throws IOException {
    if (newSocket == null) {
      throw new NullPointerException("Socket cannot be null");
    }
    socket = newSocket;
    try {
      out = new ObjectOutputStream(socket.getOutputStream()); // always add before input stream, see http://stackoverflow.com/questions/8088557/getinputstream-blocks
      in = new ObjectInputStream(socket.getInputStream());
      socket.setSoTimeout(50); // this practically makes reads non-blocking
    }
    // pass exceptions onto caller
    catch (IOException ex) {
      throw ex;
    }
  }

  /** read an object from input stream, returning null if no new message */
  public final Object read() {
    try {
      return in.readObject();
    }
    // exceptions below are thrown when no new messages
    catch (SocketTimeoutException ex) {
      return null;
    }
    catch (OptionalDataException ex) {
      return null;
    }
    // exceptions below are thrown when client disconnected
    catch (EOFException ex) {
      return new CloseConnectionMsg();
    }
    catch (SocketException ex) {
      return new CloseConnectionMsg();
    }
    catch (StreamCorruptedException ex) {
      System.out.println("Input stream corrupted: " + ex.getMessage());
      return new CloseConnectionMsg();
    }
    // print stack trace and return null if unknown error
    // (if I don't know what causes the error then I can't write code to handle it)
    catch (Exception ex) {
      System.out.println("Network read error:");
      ex.printStackTrace();
      return null;
    }
  }

  /** write specified object to output stream */
  public final void write(Object obj) {
    try {
      out.writeObject(obj);
      out.flush();
    }
    // print error message if unknown error
    // (if I don't know what causes the error then I can't write code to handle it)
    catch (IOException ex) {
      System.out.println("Network write error: " + ex.toString());
    }
  }

  /** close connection */
  public void close() {
    try {
      out.writeObject(new CloseConnectionMsg());
      out.flush();
    }
    catch (Exception ex) {
      // ignore exceptions
    }
  }

  /** setter for player name
      (does not throw exception for invalid name
       because no player in player list would have such a name) */
  public void setPlayerName(String name) {
    playerName = name;
  }

  /** getter for player name */
  public final String getPlayerName() {
    return playerName;
  }
}