如何使用java实现两台计算机的通信 源代码

一个简单的聊天程序
参考一下；

//客户端的
import java.io.*;
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class ChatClient {
public static void main(String[] args) {
ChatClient cc=new ChatClient();
cc.receive();
}
JTextField jtf;
JTextArea jta;
Socket s;
PrintWriter out;
BufferedReader in;
public ChatClient(){
JFrame frame=new JFrame("ChatClient");
frame.setSize(400,300);
jta=new JTextArea();
jta.setEditable(false);
jtf=new JTextField();
jtf.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {
send();
}

});
frame.getContentPane().add(new JScrollPane(jta));
frame.getContentPane().add(jtf,"South");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);

try {
s=new Socket("127.0.0.1",9000);
in=new BufferedReader(new InputStreamReader(s.getInputStream()));
out=new PrintWriter(s.getOutputStream());
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public void receive(){
while(true){
try {
String text=in.readLine();
this.jta.append(text+"\n");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return;
}
}
}
public void send(){
String text=this.jtf.getText();
this.jtf.setText("");
out.println(text);
out.flush();
}

}

//服务器端的
import java.net.*;
import java.io.*;
import java.util.*;
public class ChatServer {
public static void main(String[] args) throws Exception {
ServerSocket ss=new ServerSocket(9000);
List list=new ArrayList();
while(true){
Socket s=ss.accept();
list.add(s);
Thread t=new ServerThread(s,list);
t.start();
}
}

}
class ServerThread extends Thread{
Socket s;
List list;
BufferedReader in;
PrintWriter out;
public ServerThread(Socket s, List list) {
this.s = s;
this.list = list;
try {
in=new BufferedReader(new InputStreamReader(s.getInputStream()));
out=new PrintWriter(s.getOutputStream());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
public void run(){
while(true){
try {
String str=in.readLine();

if (str==null) return;
Iterator it=list.iterator();
while(it.hasNext()){
Socket socket=(Socket)(it.next());
PrintWriter o=new PrintWriter(socket.getOutputStream());
o.println(str);
o.flush();
}
} catch (IOException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
return;
}
}
}
}

客户端：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.border.TitledBorder;

public class Client{

private JFrame frame;
private JList userList;
private JTextArea textArea;
private JTextField textField;
private JTextField txt_port;
private JTextField txt_hostIp;
private JTextField txt_name;
private JButton btn_start;
private JButton btn_stop;
private JButton btn_send;
private JPanel northPanel;
private JPanel southPanel;
private JScrollPane rightScroll;
private JScrollPane leftScroll;
private JSplitPane centerSplit;

private DefaultListModel listModel;
private boolean isConnected = false;

private Socket socket;
private PrintWriter writer;
private BufferedReader reader;
private MessageThread messageThread;// 负责接收消息的线程
private Map onLineUsers = new HashMap();// 所有在线用户

// 主方法,程序入口
public static void main(String[] args) {
new Client();
}

// 执行发送
public void send() {
if (!isConnected) {
JOptionPane.showMessageDialog(frame, "还没有连接服务器，无法发送消息！", "错误",
JOptionPane.ERROR_MESSAGE);
return;
}
String message = textField.getText().trim();
if (message == null || message.equals("")) {
JOptionPane.showMessageDialog(frame, "消息不能为空！", "错误",
JOptionPane.ERROR_MESSAGE);
return;
}
sendMessage(frame.getTitle() + "@" + "ALL" + "@" + message);
textField.setText(null);
}

// 构造方法
public Client() {
textArea = new JTextArea();
textArea.setEditable(false);
textArea.setForeground(Color.blue);
textField = new JTextField();
txt_port = new JTextField("719");
txt_hostIp = new JTextField("127.0.0.1");
txt_name = new JTextField("Lei");
btn_start = new JButton("连接");
btn_stop = new JButton("断开");
btn_send = new JButton("发送");
listModel = new DefaultListModel();
userList = new JList(listModel);

northPanel = new JPanel();
northPanel.setLayout(new GridLayout(1, 7));
northPanel.add(new JLabel("端口"));
northPanel.add(txt_port);
northPanel.add(new JLabel("服务器IP"));
northPanel.add(txt_hostIp);
northPanel.add(new JLabel("姓名"));
northPanel.add(txt_name);
northPanel.add(btn_start);
northPanel.add(btn_stop);
northPanel.setBorder(new TitledBorder("连接信息"));

rightScroll = new JScrollPane(textArea);
rightScroll.setBorder(new TitledBorder("消息显示区"));
leftScroll = new JScrollPane(userList);
leftScroll.setBorder(new TitledBorder("在线用户"));
southPanel = new JPanel(new BorderLayout());
southPanel.add(textField, "Center");
southPanel.add(btn_send, "East");
southPanel.setBorder(new TitledBorder("写消息"));

centerSplit = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftScroll,
rightScroll);
centerSplit.setDividerLocation(100);

frame = new JFrame("客户机");
// 更改JFrame的图标：
//frame.setIconImage(Toolkit.getDefaultToolkit().createImage(Client.class.getResource("qq.png")));

frame.setLayout(new BorderLayout());
frame.add(northPanel, "North");
frame.add(centerSplit, "Center");
frame.add(southPanel, "South");
frame.setSize(600, 400);
int screen_width = Toolkit.getDefaultToolkit().getScreenSize().width;
int screen_height = Toolkit.getDefaultToolkit().getScreenSize().height;
frame.setLocation((screen_width - frame.getWidth()) / 2,
(screen_height - frame.getHeight()) / 2);
frame.setVisible(true);

// 写消息的文本框中按回车键时事件
textField.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
send();
}
});

// 单击发送按钮时事件
btn_send.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
send();
}
});

// 单击连接按钮时事件
btn_start.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int port;
if (isConnected) {
JOptionPane.showMessageDialog(frame, "已处于连接上状态，不要重复连接!",
"错误", JOptionPane.ERROR_MESSAGE);
return;
}
try {
try {
port = Integer.parseInt(txt_port.getText().trim());
} catch (NumberFormatException e2) {
throw new Exception("端口号不符合要求!端口为整数!");
}
String hostIp = txt_hostIp.getText().trim();
String name = txt_name.getText().trim();
if (name.equals("") || hostIp.equals("")) {
throw new Exception("姓名、服务器IP不能为空!");
}
boolean flag = connectServer(port, hostIp, name);
if (flag == false) {
throw new Exception("与服务器连接失败!");
}
frame.setTitle(name);
JOptionPane.showMessageDialog(frame, "成功连接!");
} catch (Exception exc) {
JOptionPane.showMessageDialog(frame, exc.getMessage(),
"错误", JOptionPane.ERROR_MESSAGE);
}
}
});

// 单击断开按钮时事件
btn_stop.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (!isConnected) {
JOptionPane.showMessageDialog(frame, "已处于断开状态，不要重复断开!",
"错误", JOptionPane.ERROR_MESSAGE);
return;
}
try {
boolean flag = closeConnection();// 断开连接
if (flag == false) {
throw new Exception("断开连接发生异常！");
}
JOptionPane.showMessageDialog(frame, "成功断开!");
} catch (Exception exc) {
JOptionPane.showMessageDialog(frame, exc.getMessage(),
"错误", JOptionPane.ERROR_MESSAGE);
}
}
});

// 关闭窗口时事件
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
if (isConnected) {
closeConnection();// 关闭连接
}
System.exit(0);// 退出程序
}
});
}

/**
* 连接服务器
*
* @param port
* @param hostIp
* @param name
*/
public boolean connectServer(int port, String hostIp, String name) {
// 连接服务器
try {
socket = new Socket(hostIp, port);// 根据端口号和服务器ip建立连接
writer = new PrintWriter(socket.getOutputStream());
reader = new BufferedReader(new InputStreamReader(socket
.getInputStream()));
// 发送客户端用户基本信息(用户名和ip地址)
sendMessage(name + "@" + socket.getLocalAddress().toString());
// 开启接收消息的线程
messageThread = new MessageThread(reader, textArea);
messageThread.start();
isConnected = true;// 已经连接上了
return true;
} catch (Exception e) {
textArea.append("与端口号为：" + port + " IP地址为：" + hostIp
+ " 的服务器连接失败!" + "\r\n");
isConnected = false;// 未连接上
return false;
}
}

/**
* 发送消息
*
* @param message
*/
public void sendMessage(String message) {
writer.println(message);
writer.flush();
}

/**
* 客户端主动关闭连接
*/
@SuppressWarnings("deprecation")
public synchronized boolean closeConnection() {
try {
sendMessage("CLOSE");// 发送断开连接命令给服务器
messageThread.stop();// 停止接受消息线程
// 释放资源
if (reader != null) {
reader.close();
}
if (writer != null) {
writer.close();
}
if (socket != null) {
socket.close();
}
isConnected = false;
return true;
} catch (IOException e1) {
e1.printStackTrace();
isConnected = true;
return false;
}
}

// 不断接收消息的线程
class MessageThread extends Thread {
private BufferedReader reader;
private JTextArea textArea;

// 接收消息线程的构造方法
public MessageThread(BufferedReader reader, JTextArea textArea) {
this.reader = reader;
this.textArea = textArea;
}

// 被动的关闭连接
public synchronized void closeCon() throws Exception {
// 清空用户列表
listModel.removeAllElements();
// 被动的关闭连接释放资源
if (reader != null) {
reader.close();
}
if (writer != null) {
writer.close();
}
if (socket != null) {
socket.close();
}
isConnected = false;// 修改状态为断开
}

public void run() {
String message = "";
while (true) {
try {
message = reader.readLine();
StringTokenizer stringTokenizer = new StringTokenizer(
message, "/@");
String command = stringTokenizer.nextToken();// 命令
if (command.equals("CLOSE"))// 服务器已关闭命令
{
textArea.append("服务器已关闭!\r\n");
closeCon();// 被动的关闭连接
return;// 结束线程
} else if (command.equals("ADD")) {// 有用户上线更新在线列表
String username = "";
String userIp = "";
if ((username = stringTokenizer.nextToken()) != null
&& (userIp = stringTokenizer.nextToken()) != null) {
User user = new User(username, userIp);
onLineUsers.put(username, user);
listModel.addElement(username);
}
} else if (command.equals("DELETE")) {// 有用户下线更新在线列表
String username = stringTokenizer.nextToken();
User user = (User) onLineUsers.get(username);
onLineUsers.remove(user);
listModel.removeElement(username);
} else if (command.equals("USERLIST")) {// 加载在线用户列表
int size = Integer
.parseInt(stringTokenizer.nextToken());
String username = null;
String userIp = null;
for (int i = 0; i < size; i++) {
username = stringTokenizer.nextToken();
userIp = stringTokenizer.nextToken();
User user = new User(username, userIp);
onLineUsers.put(username, user);
listModel.addElement(username);
}
} else if (command.equals("MAX")) {// 人数已达上限
textArea.append(stringTokenizer.nextToken()
+ stringTokenizer.nextToken() + "\r\n");
closeCon();// 被动的关闭连接
JOptionPane.showMessageDialog(frame, "服务器缓冲区已满！", "错误",
JOptionPane.ERROR_MESSAGE);
return;// 结束线程
} else {// 普通消息
textArea.append(message + "\r\n");
}
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}