这个曾是我的毕业设计，是得了A的。保证能用
下面的源代码分为4个文件；
chessClient.java:客户端主程序。
chessInterface.java:客户端的界面。
chessPad.java:棋盘的绘制。
chessServer.java:服务器端。
可同时容纳50个人同时在线下棋，聊天。
没有加上详细注释，不过绝对可以运行，j2sdk1.4下通过。

/*********************************************************************************************
1.chessClient.java
**********************************************************************************************/

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

class clientThread extends Thread
{
chessClient chessclient;

clientThread(chessClient chessclient)
{
this.chessclient=chessclient;
}

public void acceptMessage(String recMessage)
{
if(recMessage.startsWith("/userlist "))
{
StringTokenizer userToken=new StringTokenizer(recMessage," ");
int userNumber=0;

chessclient.userpad.userList.removeAll();
chessclient.inputpad.userChoice.removeAll();
chessclient.inputpad.userChoice.addItem("所有人");
while(userToken.hasMoreTokens())
{
String user=(String)userToken.nextToken(" ");
if(userNumber>0 && !user.startsWith("[inchess]"))
{
chessclient.userpad.userList.add(user);
chessclient.inputpad.userChoice.addItem(user);
}

userNumber++;
}
chessclient.inputpad.userChoice.select("所有人");
}
else if(recMessage.startsWith("/yourname "))
{
chessclient.chessClientName=recMessage.substring(10);
chessclient.setTitle("Java五子棋客户端 "+"用户名:"+chessclient.chessClientName);
}
else if(recMessage.equals("/reject"))
{
try
{
chessclient.chesspad.statusText.setText("不能加入游戏");
chessclient.controlpad.cancelGameButton.setEnabled(false);
chessclient.controlpad.joinGameButton.setEnabled(true);
chessclient.controlpad.creatGameButton.setEnabled(true);
}
catch(Exception ef)
{
chessclient.chatpad.chatLineArea.setText("chessclient.chesspad.chessSocket.close无法关闭");
}
chessclient.controlpad.joinGameButton.setEnabled(true);
}
else if(recMessage.startsWith("/peer "))
{
chessclient.chesspad.chessPeerName=recMessage.substring(6);
if(chessclient.isServer)
{
chessclient.chesspad.chessColor=1;
chessclient.chesspad.isMouseEnabled=true;
chessclient.chesspad.statusText.setText("请黑棋下子");
}
else if(chessclient.isClient)
{
chessclient.chesspad.chessColor=-1;
chessclient.chesspad.statusText.setText("已加入游戏，等待对方下子...");
}

}
else if(recMessage.equals("/youwin"))
{
chessclient.isOnChess=false;
chessclient.chesspad.chessVictory(chessclient.chesspad.chessColor);
chessclient.chesspad.statusText.setText("对方退出，请点放弃游戏退出连接");
chessclient.chesspad.isMouseEnabled=false;
}
else if(recMessage.equals("/OK"))
{
chessclient.chesspad.statusText.setText("创建游戏成功，等待别人加入...");
}
else if(recMessage.equals("/error"))
{
chessclient.chatpad.chatLineArea.append("传输错误：请退出程序，重新加入 \n");
}
else
{
chessclient.chatpad.chatLineArea.append(recMessage+"\n");
chessclient.chatpad.chatLineArea.setCaretPosition(
chessclient.chatpad.chatLineArea.getText().length());
}
}
public void run()
{
String message="";
try
{
while(true)
{
message=chessclient.in.readUTF();
acceptMessage(message);
}
}
catch(IOException es)
{
}
}

}
public class chessClient extends Frame implements ActionListener,KeyListener
{
userPad userpad=new userPad();
chatPad chatpad=new chatPad();
controlPad controlpad=new controlPad();
chessPad chesspad=new chessPad();
inputPad inputpad=new inputPad();

Socket chatSocket;
DataInputStream in;
DataOutputStream out;
String chessClientName=null;
String host=null;
int port=4331;

boolean isOnChat=false; //在聊天？
boolean isOnChess=false; //在下棋？
boolean isGameConnected=false; //下棋的客户端连接？
boolean isServer=false; //如果是下棋的主机
boolean isClient=false; //如果是下棋的客户端

Panel southPanel=new Panel();
Panel northPanel=new Panel();
Panel centerPanel=new Panel();
Panel westPanel=new Panel();
Panel eastPanel=new Panel();

chessClient()
{
super("Java五子棋客户端");
setLayout(new BorderLayout());
host=controlpad.inputIP.getText();

westPanel.setLayout(new BorderLayout());
westPanel.add(userpad,BorderLayout.NORTH);
westPanel.add(chatpad,BorderLayout.CENTER);
westPanel.setBackground(Color.pink);

inputpad.inputWords.addKeyListener(this);
chesspad.host=controlpad.inputIP.getText();

centerPanel.add(chesspad,BorderLayout.CENTER);
centerPanel.add(inputpad,BorderLayout.SOUTH);
centerPanel.setBackground(Color.pink);

controlpad.connectButton.addActionListener(this);
controlpad.creatGameButton.addActionListener(this);
controlpad.joinGameButton.addActionListener(this);
controlpad.cancelGameButton.addActionListener(this);
controlpad.exitGameButton.addActionListener(this);

controlpad.creatGameButton.setEnabled(false);
controlpad.joinGameButton.setEnabled(false);
controlpad.cancelGameButton.setEnabled(false);

southPanel.add(controlpad,BorderLayout.CENTER);
southPanel.setBackground(Color.pink);

addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
if(isOnChat)
{
try
{
chatSocket.close();
}
catch(Exception ed)
{
}
}
if(isOnChess || isGameConnected)
{
try
{
chesspad.chessSocket.close();
}
catch(Exception ee)
{
}
}
System.exit(0);
}
public void windowActivated(WindowEvent ea)
{

}
});

add(westPanel,BorderLayout.WEST);
add(centerPanel,BorderLayout.CENTER);
add(southPanel,BorderLayout.SOUTH);

pack();
setSize(670,548);
setVisible(true);
setResizable(false);
validate();
}
public boolean connectServer(String serverIP,int serverPort) throws Exception
{
try
{
chatSocket=new Socket(serverIP,serverPort);
in=new DataInputStream(chatSocket.getInputStream());
out=new DataOutputStream(chatSocket.getOutputStream());

clientThread clientthread=new clientThread(this);
clientthread.start();
isOnChat=true;
return true;
}
catch(IOException ex)
{
chatpad.chatLineArea.setText("chessClient:connectServer:无法连接,建议重新启动程序 \n");
}
return false;
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==controlpad.connectButton)
{
host=chesspad.host=controlpad.inputIP.getText();
try
{
if(connectServer(host,port))
{
chatpad.chatLineArea.setText("");
controlpad.connectButton.setEnabled(false);
controlpad.creatGameButton.setEnabled(true);
controlpad.joinGameButton.setEnabled(true);
chesspad.statusText.setText("连接成功，请创建游戏或加入游戏");
}

}
catch(Exception ei)
{
chatpad.chatLineArea.setText("controlpad.connectButton:无法连接,建议重新启动程序 \n");
}
}
if(e.getSource()==controlpad.exitGameButton)
{
if(isOnChat)
{
try
{
chatSocket.close();
}
catch(Exception ed)
{
}
}
if(isOnChess || isGameConnected)
{
try
{
chesspad.chessSocket.close();
}
catch(Exception ee)
{
}
}
System.exit(0);

}
if(e.getSource()==controlpad.joinGameButton)
{
String selectedUser=userpad.userList.getSelectedItem();
if(selectedUser==null || selectedUser.startsWith("[inchess]") ||
selectedUser.equals(chessClientName))
{
chesspad.statusText.setText("必须先选定一个有效用户");
}
else
{
try
{
if(!isGameConnected)
{
if(chesspad.connectServer(chesspad.host,chesspad.port))
{
isGameConnected=true;
isOnChess=true;
isClient=true;
controlpad.creatGameButton.setEnabled(false);
controlpad.joinGameButton.setEnabled(false);
controlpad.cancelGameButton.setEnabled(true);
chesspad.chessthread.sendMessage("/joingame "+userpad.userList.getSelectedItem()+" "+chessClientName);
}
}
else
{
isOnChess=true;
isClient=true;
controlpad.creatGameButton.setEnabled(false);
controlpad.joinGameButton.setEnabled(false);
controlpad.cancelGameButton.setEnabled(true);
chesspad.chessthread.sendMessage("/joingame "+userpad.userList.getSelectedItem()+" "+chessClientName);
}

}
catch(Exception ee)
{
isGameConnected=false;
isOnChess=false;
isClient=false;
controlpad.creatGameButton.setEnabled(true);
controlpad.joinGameButton.setEnabled(true);
controlpad.cancelGameButton.setEnabled(false);
chatpad.chatLineArea.setText("chesspad.connectServer无法连接 \n"+ee);
}

}
}
if(e.getSource()==controlpad.creatGameButton)
{
try
{
if(!isGameConnected)
{
if(chesspad.connectServer(chesspad.host,chesspad.port))
{
isGameConnected=true;
isOnChess=true;
isServer=true;
controlpad.creatGameButton.setEnabled(false);
controlpad.joinGameButton.setEnabled(false);
controlpad.cancelGameButton.setEnabled(true);
chesspad.chessthread.sendMessage("/creatgame "+"[inchess]"+chessClientName);
}
}
else
{
isOnChess=true;
isServer=true;
controlpad.creatGameButton.setEnabled(false);
controlpad.joinGameButton.setEnabled(false);
controlpad.cancelGameButton.setEnabled(true);
chesspad.chessthread.sendMessage("/creatgame "+"[inchess]"+chessClientName);
}
}
catch(Exception ec)
{
isGameConnected=false;
isOnChess=false;
isServer=false;
controlpad.creatGameButton.setEnabled(true);
controlpad.joinGameButton.setEnabled(true);
controlpad.cancelGameButton.setEnabled(false);
ec.printStackTrace();
chatpad.chatLineArea.setText("chesspad.connectServer无法连接 \n"+ec);
}

}
if(e.getSource()==controlpad.cancelGameButton)
{
if(isOnChess)
{
chesspad.chessthread.sendMessage("/giveup "+chessClientName);
chesspad.chessVictory(-1*chesspad.chessColor);
controlpad.creatGameButton.setEnabled(true);
controlpad.joinGameButton.setEnabled(true);
controlpad.cancelGameButton.setEnabled(false);
chesspad.statusText.setText("请建立游戏或者加入游戏");
}
if(!isOnChess)
{
controlpad.creatGameButton.setEnabled(true);
controlpad.joinGameButton.setEnabled(true);
controlpad.cancelGameButton.setEnabled(false);
chesspad.statusText.setText("请建立游戏或者加入游戏");
}
isClient=isServer=false;
}

}
public void keyPressed(KeyEvent e)
{
TextField inputWords=(TextField)e.getSource();

if(e.getKeyCode()==KeyEvent.VK_ENTER)
{
if(inputpad.userChoice.getSelectedItem().equals("所有人"))
{
try
{
out.writeUTF(inputWords.getText());
inputWords.setText("");
}
catch(Exception ea)
{
chatpad.chatLineArea.setText("chessClient:KeyPressed无法连接,建议重新连接 \n");
userpad.userList.removeAll();
inputpad.userChoice.removeAll();
inputWords.setText("");
controlpad.connectButton.setEnabled(true);
}
}
else
{
try
{
out.writeUTF("/"+inputpad.userChoice.getSelectedItem()+" "+inputWords.getText());
inputWords.setText("");
}
catch(Exception ea)
{
chatpad.chatLineArea.setText("chessClient:KeyPressed无法连接,建议重新连接 \n");
userpad.userList.removeAll();
inputpad.userChoice.removeAll();
inputWords.setText("");
controlpad.connectButton.setEnabled(true);
}
}
}
}
public void keyTyped(KeyEvent e)
{
}
public void keyReleased(KeyEvent e)
{
}
public static void main(String args[])
{
chessClient chessClient=new chessClient();
}
}
/******************************************************************************************
下面是：chessInteface.java
******************************************************************************************/

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

class userPad extends Panel
{
List userList=new List(10);

userPad()
{
setLayout(new BorderLayout());

for(int i=0;i<50;i++)
{
userList.add(i+"."+"没有用户");
}
add(userList,BorderLayout.CENTER);

}

}

class chatPad extends Panel
{
TextArea chatLineArea=new TextArea("",18,30,TextArea.SCROLLBARS_VERTICAL_ONLY);

chatPad()
{
setLayout(new BorderLayout());

add(chatLineArea,BorderLayout.CENTER);
}

}
class controlPad extends Panel
{
Label IPlabel=new Label("IP",Label.LEFT);
TextField inputIP=new TextField("localhost",10);
Button connectButton=new Button("连接主机");
Button creatGameButton=new Button("建立游戏");
Button joinGameButton=new Button("加入游戏");
Button cancelGameButton=new Button("放弃游戏");
Button exitGameButton=new Button("关闭程序");

controlPad()
{
setLayout(new FlowLayout(FlowLayout.LEFT));
setBackground(Color.pink);

add(IPlabel);
add(inputIP);
add(connectButton);
add(creatGameButton);
add(joinGameButton);
add(cancelGameButton);
add(exitGameButton);
}

}

class inputPad extends Panel
{
TextField inputWords=new TextField("",40);
Choice userChoice=new Choice();

inputPad()
{
setLayout(new FlowLayout(FlowLayout.LEFT));
for(int i=0;i<50;i++)
{
userChoice.addItem(i+"."+"没有用户");
}
userChoice.setSize(60,24);
add(userChoice);
add(inputWords);
}
}
/**********************************************************************************************
下面是：chessPad.java
**********************************************************************************************/
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;

class chessThread extends Thread
{
chessPad chesspad;

chessThread(chessPad chesspad)
{
this.chesspad=chesspad;
}

public void sendMessage(String sndMessage)
{
try
{
chesspad.outData.writeUTF(sndMessage);
}
catch(Exception ea)
{
System.out.println("chessThread.sendMessage:"+ea);
}
}
public void acceptMessage(String recMessage)
{
if(recMessage.startsWith("/chess "))
{
StringTokenizer userToken=new StringTokenizer(recMessage," ");
String chessToken;
String[] chessOpt={"-1","-1","0"};
int chessOptNum=0;

while(userToken.hasMoreTokens())
{
chessToken=(String)userToken.nextToken(" ");
if(chessOptNum>=1 && chessOptNum<=3)
{
chessOpt[chessOptNum-1]=chessToken;

}
chessOptNum++;
}
chesspad.netChessPaint(Integer.parseInt(chessOpt[0]),Integer.parseInt(chessOpt[1]),Integer.parseInt(chessOpt[2]));

}
else if(recMessage.startsWith("/yourname "))
{
chesspad.chessSelfName=recMessage.substring(10);
}
else if(recMessage.equals("/error"))
{
chesspad.statusText.setText("错误:没有这个用户，请退出程序，重新加入");
}
else
{
//System.out.println(recMessage);
}
}
public void run()
{
String message="";
try
{
while(true)
{
message=chesspad.inData.readUTF();
acceptMessage(message);
}
}
catch(IOException es)
{
}
}

}
//游戏客户端改名字
clientNameHash.put((Socket)getHashKey(clientNameHash,("[inchess]"+clientNameHash.get(clientSocket))),
("[inchess]"+clientName));
}
synchronized(chessPeerHash)
{
//chessPeerHash重新映射
chessPeerHash.put((String)getHashKey(chessPeerHash,clientNameHash.get(clientSocket)),clientName);
//向游戏客户端发送新名字
chessPeerTalk(("[inchess]"+clientName),("/yourname "+("[inchess]"+clientName)));
}
//向peer游戏客户端发送
chessPeerTalk((String)getHashKey(chessPeerHash,clientName),("/peer "+"[inchess]"+clientName));

}

public String getUserList()
{
String userList="/userlist";

for(Enumeration enu=clientNameHash.elements();enu.hasMoreElements();)
{
userList=userList+" "+(String)enu.nextElement();
}
return(userList);
}

public Object getHashKey(Hashtable targetHash,Object hashValue)
{
Object hashKey;
for(Enumeration enu=targetHash.keys();enu.hasMoreElements();)
{
hashKey=(Object)enu.nextElement();
if(hashValue.equals((Object)targetHash.get(hashKey)))
return(hashKey);
}
return(null);
}

public void firstCome()
{
publicTalk(getUserList());
Feedback("/yourname "+(String)clientNameHash.get(clientSocket));
Feedback("Java五子棋聊天客户端");
Feedback("/changename <你的名字> --更改名字");
Feedback("/list --更新用户列表");
Feedback("/<用户名> <要说的话> --私聊");
Feedback("注意：用命令的时候，先把谈话的对象定为所有人");
}

public void clientClose()
{
server.messageBoard.append("用户断开:"+clientSocket+"\n");
//如果是游戏客户端主机
synchronized(chessPeerHash)
{
if(chessPeerHash.containsKey(clientNameHash.get(clientSocket)))
{
chessPeerHash.remove((String)clientNameHash.get(clientSocket));
}
if(chessPeerHash.containsValue(clientNameHash.get(clientSocket)))
{
chessPeerHash.put((String)getHashKey(chessPeerHash,(String)clientNameHash.get(clientSocket)),"tobeclosed");
}
}
synchronized(clientDataHash)
{
clientDataHash.remove(clientSocket);
}
synchronized(clientNameHash)
{
clientNameHash.remove(clientSocket);
}
publicTalk(getUserList());
server.statusLabel.setText("当前连接数:"+clientDataHash.size());
try
{
clientSocket.close();
}
catch(IOException exx)
{
}

isClientClosed=true;

}

public void run()
{
DataInputStream inData;
synchronized(clientDataHash)
{
server.statusLabel.setText("当前连接数:"+clientDataHash.size());
}
try
{
inData=new DataInputStream(clientSocket.getInputStream());
firstCome();
while(true)