Java Socket TCP 通信，实现聊天室，服务器端指定客户端发送消息

ゝ一纸荒年。 2022-05-30 06:58 270阅读 0赞

效果图：

![70][]

李四先进入聊天室，张三也在，然后王五加入；

参考地址：[Java多线程机交互][Java]

额，原代码在客户端显示谁谁谁发送消息有个bug。。。

算了，直接上代码吧！

服务器端：

package testTCP;
    
    import java.net.*;
    
    import java.util.ArrayList;
    
    import java.util.List;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.awt.BorderLayout;
    
    import java.awt.Color;
    
    import java.awt.FlowLayout;
    
    import java.io.*;
    
    import javax.swing.JFrame;
    
    import javax.swing.JPanel;
    
    import javax.swing.JScrollPane;
    
    import javax.swing.JTextArea;
    
    public class TCPServer extends JFrame {
    
    	public static JTextArea centerTextArea = new JTextArea();
    
    	private JPanel southPanel, bottompanel;
    
    	public List<Client> list = new ArrayList<Client>();
    
    	ExecutorService cachedThreadPool = Executors.newCachedThreadPool();
    	
    
    	public void setui() throws Exception {
    
    		ServerSocket ss = new ServerSocket(5678);// 创建一个Socket服务器，监听5566端口
    
    		// TODO Auto-generated constructor stub
    
    		setTitle("服务器");
    
    		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    		setSize(400, 400);
    
    		setResizable(false); // 窗口大小不可调整
    
    		setLocationRelativeTo(null);// 窗口剧中
    
    		// 窗口的center部分
    
    		centerTextArea.setEditable(false);
    
    		centerTextArea.setBackground(new Color(211, 211, 211));
    
    		// 窗口的SHOTU部分
    
    		southPanel = new JPanel(new BorderLayout());
    
    		bottompanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 5, 5));
    
    		southPanel.add(bottompanel, BorderLayout.SOUTH);
    
    		add(new JScrollPane(centerTextArea), BorderLayout.CENTER);
    
    		add(southPanel, BorderLayout.SOUTH);
    
    		setVisible(true);
    
    		while (true) {
    
    			Socket s = ss.accept();// 利用Socket服务器的accept()方法获取客户端Socket对象。
    
    			addclient(s);
    
    			System.out.println(list.size());
    
    		}
    
    	}
    
    	// 添加客户端
    
    	private void addclient(Socket s) {
    		String name1 = "";
    
    		try {
    
    			BufferedReader in = new BufferedReader(new InputStreamReader(
    
    					s.getInputStream()));
    
    			name1 = in.readLine();
    
    		} catch (IOException e) {
    
    			// TODO Auto-generated catch block
    
    			e.printStackTrace();
    
    		}
    
    		Client c = new Client(name1, s);// 创建客户端处理线程对象
    
    		list.add(c);
    
    		//Thread t = new Thread(c);// 创建客户端处理线程
    
    		//t.start();// 启动线程
    		cachedThreadPool.execute(c);
    
    	}
    
    	// 客户端处理线程类(实现Runnable接口)
    
    	class Client implements Runnable {
    
    		String name;// 客户端名字
    
    		Socket s = null;// 保存客户端Socket对象
    
    		BufferedReader in;
    
    		PrintWriter out;
    
    		Client(String name, Socket s) {
    
    			this.s = s;
    
    			this.name = name;
    
    			try {
    
    				in = new BufferedReader(new InputStreamReader(
    
    						s.getInputStream()));
    
    				out = new PrintWriter(s.getOutputStream());
    
    				centerTextArea.append("客户端" + name + "连接成功\n");
    
    				centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    			} catch (IOException e) {
    
    				// TODO Auto-generated catch block
    
    				e.printStackTrace();
    
    			}
    
    		}
    
    		public void run() {
    
    			try {
    
    				while (true) {
    
    					String str = in.readLine();
    
    					for (int j = 0; j < list.size(); j++) {
    
    						Client c = list.get(j);
    
    						if (c != this) {
    
    							System.out.println(str);
    
    							c.send(str+"-|1|2|-"+name);
    
    						}
    
    					}
    
    					centerTextArea.append(name + "发出消息：" + str + "\n");
    
    					centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    					if (str.equals("end"))
    
    						break;
    
    				}
    
    				try {
    
    					s.close();
    
    				} catch (IOException e) {
    
    					// TODO Auto-generated catch block
    
    					e.printStackTrace();
    
    				}
    
    			} catch (IOException e1) {
    
    				// TODO Auto-generated catch block
    
    				e1.printStackTrace();
    
    			}
    
    		}
    
    		public void send(String str) {
    
    			//out.println("客户端  " + name + "说：" + str);
    			out.println(str);
    
    			out.flush();
    
    		}
    
    	}
    
    	public static void main(String[] args) throws Exception {
    
    		// 利用死循环不停的监听端口
    
    		TCPServer tc = new TCPServer();
    
    		tc.setui();
    
    	}
    
    }

客户端：

package testTCP;
    
    import java.net.*;
    
    import java.awt.BorderLayout;
    
    import java.awt.Color;
    
    import java.awt.FlowLayout;
    
    import java.awt.event.ActionEvent;
    
    import java.awt.event.ActionListener;
    
    import java.io.*;
    
    import javax.swing.JButton;
    
    import javax.swing.JFrame;
    
    import javax.swing.JLabel;
    
    import javax.swing.JOptionPane;
    
    import javax.swing.JPanel;
    
    import javax.swing.JScrollPane;
    
    import javax.swing.JTextArea;
    
    import javax.swing.JTextField;
    
    public class TCPClient extends JFrame {
    
    	private JLabel stateLB;
    
    	private JTextArea centerTextArea, inputTextArea;
    
    	private JPanel southPanel, bottompanel;
    
    	private JTextField ipTextField, remotePortTF;
    
    	private JButton sendBT, clearBT;
    
    	static Socket server;
    
    	String name = null;
    
    	PrintWriter out;
    
    	BufferedReader in;
    
    	Thread receive = new Thread(new receiveThread());
    
    	public TCPClient() throws Exception {
    
    		// 此处向服务器发送请求
    
    		server = new Socket(InetAddress.getLocalHost(), 5678);
    
    		in = new BufferedReader(new InputStreamReader(server.getInputStream()));
    
    		out = new PrintWriter(server.getOutputStream());
    
    		// 建立接收
    
    		receive.start();
    
    	}
    
    	public void setUpUI() {// 初始化面板
    
    		setTitle("客户端");
    
    		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    		setSize(400, 400);
    
    		setResizable(false); // 窗口大小不可调整
    
    		setLocationRelativeTo(null);// 窗口剧中
    
    		stateLB = new JLabel("未链接");
    
    		stateLB.setHorizontalAlignment(JLabel.RIGHT);
    
    		// 窗口的center部分
    
    		centerTextArea = new JTextArea();
    
    		centerTextArea.setEditable(false);
    
    		centerTextArea.setBackground(new Color(211, 211, 211));
    
    		// 窗口的SHOTU部分
    
    		southPanel = new JPanel(new BorderLayout());
    
    		inputTextArea = new JTextArea(5, 20);
    
    		bottompanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 5, 5));
    
    		ipTextField = new JTextField("127.0.0.1", 8);
    
    		sendBT = new JButton("发送");
    
    		clearBT = new JButton("清屏");
    
    		bottompanel.add(ipTextField);
    
    		bottompanel.add(sendBT);
    
    		bottompanel.add(clearBT);
    
    		southPanel.add(new JScrollPane(inputTextArea), BorderLayout.CENTER);
    
    		southPanel.add(bottompanel, BorderLayout.SOUTH);
    
    		add(stateLB, BorderLayout.NORTH);
    
    		add(new JScrollPane(centerTextArea), BorderLayout.CENTER);
    
    		add(southPanel, BorderLayout.SOUTH);
    
    		setVisible(true);
    
    		name = JOptionPane.showInputDialog(this, "请输入客户端的名字", JOptionPane.QUESTION_MESSAGE);
    
    		setTitle(name);
    
    		out.println(name);
    
    		out.flush();
    
    		stateLB.setText(name + "已链接");
    
    	}
    
    	public void setListener() {// 发送消息
    
    		sendBT.addActionListener(new ActionListener() {
    
    			@Override
    
    			public void actionPerformed(ActionEvent e) {
    
    				// TODO Auto-generated method stub
    
    				String sendcontent = inputTextArea.getText();
    
    				centerTextArea.append("你说："+inputTextArea.getText() + "\n");
    
    				centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    				inputTextArea.setText("");
    
    				try {
    
    					out.println(sendcontent);
    
    					out.flush();
    
    					if (sendcontent.equals("end")) {
    
    						server.close();
    
    					}
    
    				} catch (Exception e2) {
    
    					// TODO: handle exception
    
    					JOptionPane.showMessageDialog(TCPClient.this, "出错了发送不成功");
    
    					e2.printStackTrace();
    
    				}
    
    				clearBT.addActionListener(new ActionListener() {
    
    					@Override
    
    					public void actionPerformed(ActionEvent e) {
    
    						centerTextArea.setText("");// 清空面板聊天记录
    
    					}
    
    				});
    
    			}
    
    		});
    
    	}
    
    	class receiveThread implements Runnable {
    
    		// 接收线程
    
    		@Override
    
    		public void run() {
    
    			// TODO Auto-generated method stub
    
    			try {
    
    				while (server != null)
    
    				{
    
    					String info = in.readLine();
    					
    					System.out.println(info);
    
    					String message = info.split("-\\|1\\|2\\|-")[0];
    					
    					String name = info.split("-\\|1\\|2\\|-")[1];
    
    					centerTextArea.append(name + "说：" + message + "\n");
    
    					centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    				}
    
    			} catch (Exception e) {
    
    				// TODO: handle exception
    
    			}
    
    		}
    
    	}
    
    	public static void main(String[] args) throws Exception {
    		
    			TCPClient c = new TCPClient();
    
    			c.setUpUI();
    
    			c.setListener();
    		
    
    		
    
    	}
    
    }

服务器指定客户端发送消息：

这里我为了在单机上多开客户端，把代码中根据IP来分客户端换成了根据时间线来分客户端，这些都是小问题自行修改~

服务器端代码：

package MyTCP;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.PrintWriter;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Scanner;
    import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    
    import tcp.Client;
    
    public class MyTCPServer implements Runnable {
    
    	Map<String, Client> clientMap = new ConcurrentHashMap<String, Client>();
    	// 可缓存线程池 - 建客户端处理线程池
    	ExecutorService cachedThreadPool = Executors.newCachedThreadPool();
    
    	// 可缓存线程池 - 建客户端处理线程池
    	ExecutorService keepAliveThreadPool = Executors.newCachedThreadPool();
    	
    	/**
    	 * 
    	 * @param checkDelay 检查时间：单位毫秒
    	 * @param keepAliveDelay 心跳时间：单位秒
    	 */
    	public MyTCPServer(long checkDelay, long keepAliveDelay) {
    		keepAliveThreadPool.execute(new KeepAliveWatchDog(checkDelay, keepAliveDelay*1000));
    	}
    	
    	public MyTCPServer() {
    		keepAliveThreadPool.execute((new KeepAliveWatchDog(10, 15*1000)));
    	}
    	
    	public MyTCPServer(boolean keepAlive) {
    		if (keepAlive) {
    			//keepAliveThreadPool.execute((new Thread(new KeepAliveWatchDog(10, 10 * 1000))));
    			keepAliveThreadPool.execute((new KeepAliveWatchDog(10, 10 * 1000)));
    		}
    	}
    
    	public static void main(String[] args) {
    		MyTCPServer server = new MyTCPServer(true);
    		Thread t = new Thread(server);// 创建客户端处理线程
    		t.start();// 启动线程
    		@SuppressWarnings("resource")
    		Scanner scan = new Scanner(System.in);
    		while (true) {
    			System.out.println("输入操作：");
    			String op = scan.nextLine();
    			if ("1".equals(op)) {
    				for (String key : server.clientMap.keySet()) {
    					System.out.println("key = " + key);
    				}
    				for (Client value : server.clientMap.values()) {
    					System.out.println("Client = " + value.toString());
    				}
    			} else {
    				System.out.println("输入地址");
    				String ClientIp = scan.nextLine();
    				System.out.println("输入地址是：" + ClientIp);
    				System.out.println("输入消息");
    				String message = scan.nextLine();
    				System.out.println("输入消息：" + message);
    
    				Client c = server.clientMap.get(ClientIp);
    				if(c!=null){
    					c.send(ClientIp, message);
    				}else{
    					System.out.println("该链接不存在！");
    				}
    				
    			}
    
    		}
    	}
    
    	@SuppressWarnings("resource")
    	@Override
    	public void run() {
    		ServerSocket ss = null;
    		try {
    			ss = new ServerSocket(5678);// 创建一个Socket服务器，监听5566端口
    			System.out.println("服务已启动。。。");
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		while (true) {
    			Socket client = null;
    			try {
    				client = ss.accept();
    				addclient(client);
    			} catch (IOException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    
    		}
    	}
    
    	// 添加客户端
    	private void addclient(Socket s) {
    		// 第一次收到客户端信息
    		/*
    		 * String message; try { BufferedReader in = new BufferedReader(new
    		 * InputStreamReader( s.getInputStream())); message = in.readLine(); }
    		 * catch (IOException e) { e.printStackTrace(); }
    		 */
    		Client c = new Client(s);// 创建客户端处理线程对象
    		// clientMap.put(s.getInetAddress().toString().replace("/", ""), c);
    		clientMap.put(System.currentTimeMillis() + "", c);
    
    		try {
    			Thread.sleep(10);
    		} catch (InterruptedException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    
    		// Thread t = new Thread(c);// 创建客户端处理线程
    		// t.start();// 启动线程
    		cachedThreadPool.execute(c);
    
    		// 遍历
    		/*
    		 * for (String key : clientMap.keySet()) { System.out.println("key = " +
    		 * key); } for (Client value : clientMap.values()) { System.out.println(
    		 * "Client = " + value.toString()); }
    		 */
    
    	}
    
    	class Client implements Runnable {
    		Socket s = null;// 保存客户端Socket对象
    		BufferedReader in;
    		PrintWriter out;
    		String toClient;
    		String ClientIp;
    		boolean send = false;
    
    		Client(Socket s) {
    			this.s = s;
    			try {
    				in = new BufferedReader(new InputStreamReader(s.getInputStream()));
    				out = new PrintWriter(s.getOutputStream());
    			} catch (IOException e) {
    				e.printStackTrace();
    
    			}
    		}
    
    		void send(String ClientIp, String message) {
    			this.ClientIp = ClientIp;
    			this.toClient = message;
    			send = true;
    			if (send) {
    				Client c = clientMap.get(ClientIp);
    				if (c == null) {
    					System.out.println(ClientIp + "连接不存在！");
    				}
    
    				try {
    					c.send(toClient);
    				} catch (Exception e) {
    					e.printStackTrace();
    					c.close();
    				}
    
    			}
    			send = false;
    		}
    
    		@Override
    		public void run() {
    
    			while (true) {
    				try {
    					String str = null;
    					// str = in.readLine();
    					if ((str = in.readLine()) != null) {
    						System.out.println(s.getInetAddress().toString().replace("/", "") + ":" + str);
    					}
    				} catch (Exception e) {
    					// e.printStackTrace();
    					close();
    					break;
    				}
    
    				/*
    				 * if (send) { Client c = clientMap.get(ClientIp);
    				 * c.send(toClient); } send = false;
    				 */
    			}
    		}
    
    		public void send(String str) {
    			out.println(str);
    			if (!"KeepAlive".equals(str))
    				System.out.println("send:" + str);
    			out.flush();
    
    		}
    
    		public void close() {
    			try {
    				s.close();
    				in.close();
    				;
    				out.close();
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    			clientMap.remove(s.getInetAddress().toString().replace("/", ""));
    			System.out.println(s.getInetAddress().toString().replace("/", "") + "连接已关闭！");
    		}
    
    	}
    
    	class KeepAliveWatchDog implements Runnable {
    		long lastSendTime;
    		long checkDelay = 10;
    		long keepAliveDelay = 10000;
    
    		
    		/**
    		 * 
    		 * @param checkDelay 检查时间
    		 * @param keepAliveDelay 心跳时间
    		 */
    		public KeepAliveWatchDog(long checkDelay, long keepAliveDelay) {
    			this.checkDelay = checkDelay;
    			this.keepAliveDelay = keepAliveDelay;
    		}
    
    		@Override
    		public void run() {
    			while (true) {
    				if (System.currentTimeMillis() - lastSendTime > keepAliveDelay) {
    					for (String ClientIp : clientMap.keySet()) {
    						Client c = clientMap.get(ClientIp);
    						c.send("KeepAlive");
    					}
    					lastSendTime = System.currentTimeMillis();
    				} else {
    					try {
    						Thread.sleep(checkDelay);
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    
    					}
    				}
    			}
    		}
    	}
    
    }

客户端，略微修改：

package MyTCP;
    
    import java.net.*;
    
    import java.awt.BorderLayout;
    
    import java.awt.Color;
    
    import java.awt.FlowLayout;
    
    import java.awt.event.ActionEvent;
    
    import java.awt.event.ActionListener;
    
    import java.io.*;
    
    import javax.swing.JButton;
    
    import javax.swing.JFrame;
    
    import javax.swing.JLabel;
    
    import javax.swing.JOptionPane;
    
    import javax.swing.JPanel;
    
    import javax.swing.JScrollPane;
    
    import javax.swing.JTextArea;
    
    import javax.swing.JTextField;
    
    public class MyTCPClient extends JFrame {
    
    	private JLabel stateLB;
    
    	private JTextArea centerTextArea, inputTextArea;
    
    	private JPanel southPanel, bottompanel;
    
    	private JTextField ipTextField, remotePortTF;
    
    	private JButton sendBT, clearBT;
    
    	static Socket server;
    
    	String name = null;
    
    	PrintWriter out;
    
    	BufferedReader in;
    
    	Thread receive = new Thread(new receiveThread());
    
    	public MyTCPClient() throws Exception {
    
    		// 此处向服务器发送请求
    
    		server = new Socket(InetAddress.getLocalHost(), 5678);
    
    		in = new BufferedReader(new InputStreamReader(server.getInputStream()));
    
    		out = new PrintWriter(server.getOutputStream());
    
    		// 建立接收
    
    		receive.start();
    
    	}
    
    	public void setUpUI() {// 初始化面板
    
    		setTitle("客户端");
    
    		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    		setSize(400, 400);
    
    		setResizable(false); // 窗口大小不可调整
    
    		setLocationRelativeTo(null);// 窗口剧中
    
    		stateLB = new JLabel("未链接");
    
    		stateLB.setHorizontalAlignment(JLabel.RIGHT);
    
    		// 窗口的center部分
    
    		centerTextArea = new JTextArea();
    
    		centerTextArea.setEditable(false);
    
    		centerTextArea.setBackground(new Color(211, 211, 211));
    
    		// 窗口的SHOTU部分
    
    		southPanel = new JPanel(new BorderLayout());
    
    		inputTextArea = new JTextArea(5, 20);
    
    		bottompanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 5, 5));
    
    		ipTextField = new JTextField("127.0.0.1", 8);
    
    		sendBT = new JButton("发送");
    
    		clearBT = new JButton("清屏");
    
    		bottompanel.add(ipTextField);
    
    		bottompanel.add(sendBT);
    
    		bottompanel.add(clearBT);
    
    		southPanel.add(new JScrollPane(inputTextArea), BorderLayout.CENTER);
    
    		southPanel.add(bottompanel, BorderLayout.SOUTH);
    
    		add(stateLB, BorderLayout.NORTH);
    
    		add(new JScrollPane(centerTextArea), BorderLayout.CENTER);
    
    		add(southPanel, BorderLayout.SOUTH);
    
    		setVisible(true);
    
    		stateLB.setText(name + "已链接");
    
    	}
    
    	public void setListener() {// 发送消息
    
    		sendBT.addActionListener(new ActionListener() {
    
    			@Override
    
    			public void actionPerformed(ActionEvent e) {
    
    				// TODO Auto-generated method stub
    
    				String sendcontent = inputTextArea.getText();
    
    				centerTextArea.append("你说：" + inputTextArea.getText() + "\n");
    
    				centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    				inputTextArea.setText("");
    
    				try {
    
    					out.println(sendcontent);
    
    					out.flush();
    
    					if (sendcontent.equals("end")) {
    
    						server.close();
    
    					}
    
    				} catch (Exception e2) {
    
    					// TODO: handle exception
    
    					JOptionPane.showMessageDialog(MyTCPClient.this, "出错了发送不成功");
    
    					e2.printStackTrace();
    
    				}
    
    				clearBT.addActionListener(new ActionListener() {
    
    					@Override
    
    					public void actionPerformed(ActionEvent e) {
    
    						centerTextArea.setText("");// 清空面板聊天记录
    
    					}
    
    				});
    
    			}
    
    		});
    
    	}
    
    	class receiveThread implements Runnable {
    
    		// 接收线程
    
    		@Override
    
    		public void run() {
    
    			// TODO Auto-generated method stub
    
    			try {
    
    				while (server != null)
    
    				{
    
    					String info = in.readLine();
    
    					centerTextArea.append(info + "\n");
    
    					centerTextArea.setCaretPosition(centerTextArea.getText().length());
    
    				}
    
    			} catch (Exception e) {
    
    				// TODO: handle exception
    
    			}
    
    		}
    
    	}
    
    	public static void main(String[] args) throws Exception {
    
    		MyTCPClient c = new MyTCPClient();
    
    		c.setUpUI();
    
    		c.setListener();
    
    	}
    
    }

运行效果：

![70 1][]

keepAlive是心跳包。。

输入操作字符1是查看所有客户端；

其他就是制定客户端发送消息；

![70 2][]

当然，这里关闭客户端的时候代码没改。。。是根据IP来关闭客户端的，所以关闭后仍可以在服务器上看到；

把根据时间线的代码换成原来的就好；

![70 3][]

这时把客户端关闭：

![70 4][]

好，基本这样~

[70]: /images/20220530/36268c9ff69a4ca1a127091ce0c2555d.png
[Java]: http://blog.csdn.net/u012373815/article/details/47209077
[70 1]: /images/20220530/8cc3f239255d413eb580862ceedd2245.png
[70 2]: /images/20220530/8568cfe916aa41bbbe1f68082bfa6423.png
[70 3]: /images/20220530/8f51bad59f0b40ec9b8e147092721dbe.png
[70 4]: /images/20220530/a7cd70198efb41fe927aa2176f487169.png