本文实例为大家分享了java局域网聊天程序的具体代码，供大家参考，具体内容如下

有服务器端 和客户端两个界面，运行需要加上自己的ip地址，端口可以随意，但是客户端端口，和服务器端口要一样，然后就可以几个人一块聊天了

简单贴几个代码吧

Client.java 客户端代码

package chat; import java.awt.BorderLayout;//布置容器的边框布局import java.awt.Color;import java.awt.Container;import java.awt.GridLayout;//布局处理器import java.awt.Toolkit;//抽象超类import java.awt.event.ActionEvent;//指示发生了组件定义的动作的语义事件import java.awt.event.ActionListener;//用于接收操作事件的侦听器接口import java.awt.event.MouseEvent;//指示组件中发生鼠标动作的事件import java.awt.event.MouseListener;//鼠标事件的侦听器接口import java.awt.event.WindowAdapter;//接收窗口事件的抽象适配器类。此类中的方法为空。此类存在的目的是方便创建侦听器对象import java.awt.event.WindowEvent;//指示窗口状态改变的低级别事件import java.io.BufferedReader;//提供通用的缓冲方式文本读取import java.io.IOException;//输入输出异常import java.io.InputStreamReader;//字节流通向字符流的桥梁import java.io.PrintWriter;//向文本输出流打印对象的格式化表示形式import java.net.Socket;//套接字，网络上的两个程序通过一个双向的通信连接实现数据交换的通信import java.util.HashMap;// HashMap 是 Map 接口的常用实现类import java.util.Map;//存数据，将键映射到值的对象import java.util.StringTokenizer;//允许应用程序将字符串分解为标记 import javax.swing.BorderFactory;//创建一个浮雕式的边框import javax.swing.DefaultListModel;//列表模型import javax.swing.JButton;//按钮import javax.swing.JFrame;//窗口import javax.swing.JLabel;//标签import javax.swing.JList;//列表import javax.swing.JOptionPane;//对话框import javax.swing.JPanel;import javax.swing.JScrollPane;//视图import javax.swing.JSplitPane;//分隔import javax.swing.JTextArea;//多行文本import javax.swing.JTextField;//文本import javax.swing.border.EmptyBorder;//一个占用空间但不执行绘制的空透明边框import javax.swing.border.TitledBorder;//该类实现在指定位置以指定对齐方式显示字符串标题的任意边框 import oldchat.ChatFrame; 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;//创建套接字 private PrintWriter writer; private BufferedReader reader; private MessageThread messageThread;// 负责接收消息的线程 private Map<String, User> onLineUsers = new HashMap<String, User>();// 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("6666"); txt_hostIp = new JTextField(); txt_name = new JTextField(); 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("群聊消息显示区")); leftScroll = new JScrollPane(userList); leftScroll.setBorder(new TitledBorder("在线用户(双击私聊)")); 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("客户端"); // 更改JFrame的图标： //frame.setIconImage(Toolkit.getDefaultToolkit().createImage(Client.class.getResource("qq.jpg"))); 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); } } });//双击聊天（私聊） userList.addMouseListener(new MouseListener() { public void mouseReleased(MouseEvent e) {} public void mousePressed(MouseEvent e) {} public void mouseExited(MouseEvent e) {} public void mouseEntered(MouseEvent e) {} public void mouseClicked(MouseEvent e) { if(e.getClickCount()==2) { User user=onLineUsers.get(userList.getSelectedValue()); ChatFrame.main(user.getIp());; } } }); // 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(); } } } } }

Server.java

package chat; 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.BindException;import java.net.ServerSocket;import java.net.Socket;import java.util.ArrayList;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 Server { private JFrame frame; private JTextArea contentArea; private JTextField txt_message; private JTextField txt_max; private JTextField txt_port; private JButton btn_start; private JButton btn_stop; private JButton btn_send; private JPanel northPanel; private JPanel southPanel; private JScrollPane rightPanel; private JScrollPane leftPanel; private JSplitPane centerSplit; private JList userList; private DefaultListModel listModel; private ServerSocket serverSocket; private ServerThread serverThread; private ArrayList<ClientThread> clients; private boolean isStart = false; // 主方法,程序执行入口 public static void main(String[] args) { new Server(); } // 执行消息发送 public void send() { if (!isStart) { JOptionPane.showMessageDialog(frame, "服务器还未启动,不能发送消息！", "错误", JOptionPane.ERROR_MESSAGE); return; } if (clients.size() == 0) { JOptionPane.showMessageDialog(frame, "没有用户在线,不能发送消息！", "错误", JOptionPane.ERROR_MESSAGE); return; } String message = txt_message.getText().trim(); if (message == null || message.equals("")) { JOptionPane.showMessageDialog(frame, "消息不能为空！", "错误", JOptionPane.ERROR_MESSAGE); return; } sendServerMessage(message);// 群发服务器消息 contentArea.append("服务器说：" + txt_message.getText() + "\r\n"); txt_message.setText(null); } // 构造放法 public Server() { frame = new JFrame("服务器"); // 更改JFrame的图标： //frame.setIconImage(Toolkit.getDefaultToolkit().createImage(Client.class.getResource("qq.png"))); //frame.setIconImage(Toolkit.getDefaultToolkit().createImage(Server.class.getResource("qq.jpg"))); contentArea = new JTextArea(); contentArea.setEditable(false); contentArea.setForeground(Color.blue); txt_message = new JTextField(); txt_max = new JTextField("30"); txt_port = new JTextField("6666"); btn_start = new JButton("启动"); btn_stop = new JButton("停止"); btn_send = new JButton("发送"); btn_stop.setEnabled(false); listModel = new DefaultListModel(); userList = new JList(listModel); southPanel = new JPanel(new BorderLayout()); southPanel.setBorder(new TitledBorder("写消息")); southPanel.add(txt_message, "Center"); southPanel.add(btn_send, "East"); leftPanel = new JScrollPane(userList); leftPanel.setBorder(new TitledBorder("在线用户")); rightPanel = new JScrollPane(contentArea); rightPanel.setBorder(new TitledBorder("群聊消息显示区")); centerSplit = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftPanel, rightPanel); centerSplit.setDividerLocation(100); northPanel = new JPanel(); northPanel.setLayout(new GridLayout(1, 6)); northPanel.add(new JLabel("人数上限")); northPanel.add(txt_max); northPanel.add(new JLabel("端口")); northPanel.add(txt_port); northPanel.add(btn_start); northPanel.add(btn_stop); northPanel.setBorder(new TitledBorder("配置信息")); frame.setLayout(new BorderLayout()); frame.add(northPanel, "North"); frame.add(centerSplit, "Center"); frame.add(southPanel, "South"); frame.setSize(600, 400); //frame.setSize(Toolkit.getDefaultToolkit().getScreenSize());//设置全屏 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); // 关闭窗口时事件 frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { if (isStart) { closeServer();// 关闭服务器 } System.exit(0);// 退出程序 } }); // 文本框按回车键时事件 txt_message.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { send(); } }); // 单击发送按钮时事件 btn_send.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { send(); } }); // 单击启动服务器按钮时事件 btn_start.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if (isStart) { JOptionPane.showMessageDialog(frame, "服务器已处于启动状态，不要重复启动！", "错误", JOptionPane.ERROR_MESSAGE); return; } int max; int port; try { try { max = Integer.parseInt(txt_max.getText()); } catch (Exception e1) { throw new Exception("人数上限为正整数！"); } if (max <= 0) { throw new Exception("人数上限为正整数！"); } try { port = Integer.parseInt(txt_port.getText()); } catch (Exception e1) { throw new Exception("端口号为正整数！"); } if (port <= 0) { throw new Exception("端口号 为正整数！"); } serverStart(max, port); contentArea.append("服务器已成功启动!人数上限：" + max + ",端口：" + port + "\r\n"); JOptionPane.showMessageDialog(frame, "服务器成功启动!"); btn_start.setEnabled(false); txt_max.setEnabled(false); txt_port.setEnabled(false); btn_stop.setEnabled(true); } catch (Exception exc) { JOptionPane.showMessageDialog(frame, exc.getMessage(), "错误", JOptionPane.ERROR_MESSAGE); } } }); // 单击停止服务器按钮时事件 btn_stop.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if (!isStart) { JOptionPane.showMessageDialog(frame, "服务器还未启动，无需停止！", "错误", JOptionPane.ERROR_MESSAGE); return; } try { closeServer(); btn_start.setEnabled(true); txt_max.setEnabled(true); txt_port.setEnabled(true); btn_stop.setEnabled(false); contentArea.append("服务器成功停止!\r\n"); JOptionPane.showMessageDialog(frame, "服务器成功停止！"); } catch (Exception exc) { JOptionPane.showMessageDialog(frame, "停止服务器发生异常！", "错误", JOptionPane.ERROR_MESSAGE); } } }); } // 启动服务器 public void serverStart(int max, int port) throws java.net.BindException { try { clients = new ArrayList<ClientThread>(); serverSocket = new ServerSocket(port); serverThread = new ServerThread(serverSocket, max); serverThread.start(); isStart = true; } catch (BindException e) { isStart = false; throw new BindException("端口号已被占用，请换一个！"); } catch (Exception e1) { e1.printStackTrace(); isStart = false; throw new BindException("启动服务器异常！"); } } // 关闭服务器 @SuppressWarnings("deprecation") public void closeServer() { try { if (serverThread != null) serverThread.stop();// 停止服务器线程 for (int i = clients.size() - 1; i >= 0; i--) { // 给所有在线用户发送关闭命令 clients.get(i).getWriter().println("CLOSE"); clients.get(i).getWriter().flush(); // 释放资源 clients.get(i).stop();// 停止此条为客户端服务的线程 clients.get(i).reader.close(); clients.get(i).writer.close(); clients.get(i).socket.close(); clients.remove(i); } if (serverSocket != null) { serverSocket.close();// 关闭服务器端连接 } listModel.removeAllElements();// 清空用户列表 isStart = false; } catch (IOException e) { e.printStackTrace(); isStart = true; } } // 群发服务器消息 public void sendServerMessage(String message) { for (int i = clients.size() - 1; i >= 0; i--) { clients.get(i).getWriter().println("服务器：" + message); clients.get(i).getWriter().flush(); } } // 服务器线程 class ServerThread extends Thread { private ServerSocket serverSocket; private int max;// 人数上限 // 服务器线程的构造方法 public ServerThread(ServerSocket serverSocket, int max) { this.serverSocket = serverSocket; this.max = max; } public void run() { while (true) {// 不停的等待客户端的链接 try { Socket socket = serverSocket.accept(); if (clients.size() == max) {// 如果已达人数上限 BufferedReader r = new BufferedReader( new InputStreamReader(socket.getInputStream())); PrintWriter w = new PrintWriter(socket .getOutputStream()); // 接收客户端的基本用户信息 String inf = r.readLine(); StringTokenizer st = new StringTokenizer(inf, "@"); User user = new User(st.nextToken(), st.nextToken()); // 反馈连接成功信息 w.println("MAX@服务器：对不起，" + user.getName() + user.getIp() + "，服务器在线人数已达上限，请稍后尝试连接！"); w.flush(); // 释放资源 r.close(); w.close(); socket.close(); continue; } ClientThread client = new ClientThread(socket); client.start();// 开启对此客户端服务的线程 clients.add(client); listModel.addElement(client.getUser().getName());// 更新在线列表 contentArea.append(client.getUser().getName() + client.getUser().getIp() + "上线!\r\n"); } catch (IOException e) { e.printStackTrace(); } } } } // 为一个客户端服务的线程 class ClientThread extends Thread { private Socket socket; private BufferedReader reader; private PrintWriter writer; private User user; public BufferedReader getReader() { return reader; } public PrintWriter getWriter() { return writer; } public User getUser() { return user; } // 客户端线程的构造方法 public ClientThread(Socket socket) { try { this.socket = socket; reader = new BufferedReader(new InputStreamReader(socket .getInputStream())); writer = new PrintWriter(socket.getOutputStream()); // 接收客户端的基本用户信息 String inf = reader.readLine(); StringTokenizer st = new StringTokenizer(inf, "@"); user = new User(st.nextToken(), st.nextToken()); // 反馈连接成功信息 writer.println(user.getName() + user.getIp() + "与服务器连接成功!"); writer.flush(); // 反馈当前在线用户信息 if (clients.size() > 0) { String temp = ""; for (int i = clients.size() - 1; i >= 0; i--) { temp += (clients.get(i).getUser().getName() + "/" + clients .get(i).getUser().getIp()) + "@"; } writer.println("USERLIST@" + clients.size() + "@" + temp); writer.flush(); } // 向所有在线用户发送该用户上线命令 for (int i = clients.size() - 1; i >= 0; i--) { clients.get(i).getWriter().println( "ADD@" + user.getName() + user.getIp()); clients.get(i).getWriter().flush(); } } catch (IOException e) { e.printStackTrace(); } } @SuppressWarnings("deprecation") public void run() {// 不断接收客户端的消息，进行处理。 String message = null; while (true) { try { message = reader.readLine();// 接收客户端消息 if (message.equals("CLOSE"))// 下线命令 { contentArea.append(this.getUser().getName() + this.getUser().getIp() + "下线!\r\n"); // 断开连接释放资源 reader.close(); writer.close(); socket.close(); // 向所有在线用户发送该用户的下线命令 for (int i = clients.size() - 1; i >= 0; i--) { clients.get(i).getWriter().println( "DELETE@" + user.getName()); clients.get(i).getWriter().flush(); } listModel.removeElement(user.getName());// 更新在线列表 // 删除此条客户端服务线程 for (int i = clients.size() - 1; i >= 0; i--) { if (clients.get(i).getUser() == user) { ClientThread temp = clients.get(i); clients.remove(i);// 删除此用户的服务线程 temp.stop();// 停止这条服务线程 return; } } } else { dispatcherMessage(message);// 转发消息 } } catch (IOException e) { e.printStackTrace(); } } } // 转发消息 public void dispatcherMessage(String message) { StringTokenizer stringTokenizer = new StringTokenizer(message, "@"); String source = stringTokenizer.nextToken(); String owner = stringTokenizer.nextToken(); String content = stringTokenizer.nextToken(); message = source + "说：" + content; contentArea.append(message + "\r\n"); if (owner.equals("ALL")) {// 群发 for (int i = clients.size() - 1; i >= 0; i--) { clients.get(i).getWriter().println(message); clients.get(i).getWriter().flush(); } } } }}

运行截图

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