java 用udp，tcp协议实现的局域网聊天程序 期末大作业 可私聊，群聊

package liaotian; 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_more { private JFrame frame; private JTextArea contentArea; //文本域 private JTextField txt_message; //用于显示文本信息 private JTextField txt_max; //设置最大连接人数 private JTextField txt_port; //设置端口号 private JButton btn_start; //开始按钮 private JButton btn_stop; //断开按钮 private JButton btn_send; //发送按钮 private JPanel northPanel; //北方面板 private JPanel southPanel; //南方面板 private JScrollPane rightPanel; //左边滚动条 private JScrollPane leftPanel; //右边滚动条 private JSplitPane centerSplit; //分割线 private JList userList; //列表组件 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_more(); } // 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：" + txt_message.getText() + "\r\n"); txt_message.setText(null); } // 构造放法 public Server_more() { 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.png"))); contentArea = new JTextArea(); contentArea.setEditable(false); contentArea.setForeground(Color.blue); txt_message = new JTextField(); txt_max = new JTextField("30"); txt_port = new JTextField("5678"); 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("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 actionPer