tictactoeclient.java

此源码为机械工业出版社出版的《Java语言程序设计》第三版所配套的书中所有源代码。

// TicTacToeClient.java: Play the TicTacToe game
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.LineBorder;
import java.io.*;
import java.net.*;

public class TicTacToeClient extends JApplet
  implements Runnable, TicTacToeConstants
{
  // Indicate whether the player has the turn
  private boolean myTurn = false;

  // Indicate the token for the player
  private char myToken = ' ';

  // Indicate the token for the other player
  private char otherToken = ' ';

  // Create and initialize cells
  private Cell[][] cell =  new Cell[3][3];

  // Create and initialize a title label
  private JLabel jlblTitle = new JLabel();

  // Create and initialize a status label
  private JLabel jlblStatus = new JLabel();

  // Indicate selected row and column by the current move
  private int rowSelected;
  private int columnSelected;
  
  // Input and output streams from/to server
  private DataInputStream isFromServer;
  private DataOutputStream osToServer;

  // Continue to play?
  private boolean continueToPlay = true;

  // Wait for the player to mark a cell
  private boolean waiting = true;

  // Initialize UI
  public void init()
  {
    // Panel p to hold cells
    JPanel p = new JPanel();
    p.setLayout(new GridLayout(3, 3, 0, 0));
    for (int i=0; i<3; i++)
      for (int j=0; j<3; j++)
        p.add(cell[i][j] = new Cell(i, j));

    // Set properties for labels and borders for labels and panel
    p.setBorder(new LineBorder(Color.black, 1));
    jlblTitle.setHorizontalAlignment(JLabel.CENTER);
    jlblTitle.setFont(new Font("SansSerif", Font.BOLD, 16));
    jlblTitle.setBorder(new LineBorder(Color.black, 1));
    jlblStatus.setBorder(new LineBorder(Color.black, 1));

    // Place the panel and the labels to the applet
    this.getContentPane().add(jlblTitle, BorderLayout.NORTH);
    this.getContentPane().add(p, BorderLayout.CENTER);
    this.getContentPane().add(jlblStatus, BorderLayout.SOUTH);

    // Connect to the server
    connectToServer();
  }

  private void connectToServer()
  {
    try
    {
      // Create a socket to connect to the server
      Socket connectToServer = new Socket("localhost", 8000);

      // Create an input stream to receive data from the server
      isFromServer = new DataInputStream(
        connectToServer.getInputStream());

      // Create an output stream to send data to the server
      osToServer =
        new DataOutputStream(connectToServer.getOutputStream());
    }
    catch (Exception ex)
    {
      System.err.println(ex);
    }

    // Control the game on a separate thread
    Thread thread = new Thread(this);
    thread.start();
  }

  // This main method enables the applet to run as an application
  public static void main(String[] args)
  {
    // Create a frame
    JFrame frame = new JFrame("Tic Tac Toe Client");

    // Create an instance of the applet
    TicTacToeClient applet = new TicTacToeClient();

    // Add the applet instance to the frame
    frame.getContentPane().add(applet, BorderLayout.CENTER);

    // Invoke init() and start()
    applet.init();
    applet.start();

    // Display the frame
    frame.setSize(320, 300);
    // frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }

  public void run()
  {
    try
    {
      // Get notification from the server
      int player = isFromServer.readInt();

      // Am I player 1 or 2?
      if (player == PLAYER1)
      {
        myToken = 'X';
        otherToken = 'O';
        jlblTitle.setText("Player 1 with token 'X'");
        jlblStatus.setText("Waiting for player 2 to join");

        // Receive startup notification from the server
        isFromServer.readInt(); // Whatever read is ignored

        // The other player has joined
        jlblStatus.setText("Player 2 has joined. I start first");

        // It is my turn
        myTurn = true;
      }
      else if (player == PLAYER2)
      {
        myToken = 'O';
        otherToken = 'X';
        jlblTitle.setText("Player 2 with token 'O'");
        jlblStatus.setText("Waiting for player 1 to move");
      }

      // Continue to play
      while (continueToPlay)
      {
        if (player == PLAYER1)
        {
          waitForPlayerAction(); // Wait for player 1 to move
          sendMove(); // Send the move to the server
          receiveInfoFromServer(); // Receive info from the server
        }
        else if (player == PLAYER2)
        {
          receiveInfoFromServer(); // Receive info from the server
          waitForPlayerAction(); // Wait for player 2 to move
          sendMove(); // Send player 2's move to the server
        }
      }
    }
    catch (Exception ex)
    { }
  }

  // Wait for the player to mark a cell
  private void waitForPlayerAction() throws InterruptedException
  {
    while (waiting)
    {
      Thread.sleep(100);
    }

    waiting = true;
  }

  // Send this player's move to the server
  private void sendMove() throws IOException
  {
    osToServer.writeInt(rowSelected); // Send the selected row
    osToServer.writeInt(columnSelected); // Send the selected column
  }

  // Receive info from the server
  private void receiveInfoFromServer() throws IOException
  {
    // Receive game status
    int status = isFromServer.readInt();

    if (status == PLAYER1_WON)
    {
      // Player 1 won, stop playing
      continueToPlay = false;
      if (myToken == 'X')
      {
        jlblStatus.setText("I won! (X)");
      }
      else if (myToken == 'O')
      {
        jlblStatus.setText("Player 1 (X) has won!");
        receiveMove();
      }
    }
    else if (status == PLAYER2_WON)
    {
      // Player 2 won, stop playing
      continueToPlay = false;
      if (myToken == 'O')
      {
        jlblStatus.setText("I won! (O)");
      }
      else if (myToken == 'X')
      {
        jlblStatus.setText("Player 2 (O) has won!");
        receiveMove();
      }
    }
    else if (status == DRAW)
    {
      // No winner, game is over
      continueToPlay = false;
      jlblStatus.setText("Game is over, no winner!");

      //
      if (myToken == 'O')
      {
        receiveMove();
      }
    }
    else
    {
      receiveMove();
      jlblStatus.setText("My turn");
      myTurn = true; // It is my turn
    }
  }

  private void receiveMove() throws IOException
  {
    // Get the other player's move
    int row = isFromServer.readInt();
    int column = isFromServer.readInt();
    cell[row][column].setToken(otherToken);
  }

  // An inner class for a cell
  public class Cell extends JPanel implements MouseListener
  {
    // Indicate the row and column of this cell in the board
    private int row;
    private int column;

    // Token used for this cell
    private char token = ' ';

    public Cell(int row, int column)
    {
      this.row = row;
      this.column = column;
      setBorder(new LineBorder(Color.black, 1)); // Set cell's border
      addMouseListener(this);  // Register listener
    }

    // The getter method for token
    public char getToken()
    {
      return token;
    }

    // The setter method for token
    public void setToken(char c)
    {
      token = c;
      repaint();
    }

    // Paint the cell
    public void paintComponent(Graphics g)
    {
      super.paintComponent(g);

      if (token == 'X')
      {
        g.drawLine(10, 10, getSize().width-10, getSize().height-10);
        g.drawLine(getSize().width-10, 10, 10, getSize().height-10);
      }
      else if (token == 'O')
      {
        g.drawOval(10, 10, getSize().width-20, getSize().height-20);
      }
    }

    // Handle mouse click on a cell
    public void mouseClicked(MouseEvent e)
    {
      // If cell is not occupied and the player has the turn
      if ((token == ' ') && myTurn)
      {
        setToken(myToken);  // Set the player's token in the cell
        myTurn = false;
        rowSelected = row;
        columnSelected = column;
        jlblStatus.setText("Waiting for the other player to move");
        waiting = false; // Just completed a succeful move
      }
    }

    public void mousePressed(MouseEvent e)
    {
      // TODO: implement this java.awt.event.MouseListener method;
    }

    public void mouseReleased(MouseEvent e)
    {
      // TODO: implement this java.awt.event.MouseListener method;
    }

    public void mouseEntered(MouseEvent e)
    {
      // TODO: implement this java.awt.event.MouseListener method;
    }

    public void mouseExited(MouseEvent e)
    {
      // TODO: implement this java.awt.event.MouseListener method;
    }
  }
}