[java]局域网简易聊天

 

import java.io.IOException;
import java.net.*;
import java.util.ArrayList;
import java.util.List;
import java.io.*;

public class ChatServer {
    boolean started = false;
    ServerSocket ss = null;
    List<Client> clients = new ArrayList<Client>();

    public static void main(String[] args) {
        new ChatServer().start();
    }

    public void start() {
        try {
            ss = new ServerSocket(8888);
            started = true;
        } catch (IOException ex) {
            System.out.println("Socket连接失败！端口使用中");
            ex.printStackTrace();
        }

        try {
            while (started) {
                Socket socket = ss.accept();
                Client c = new Client(socket);//将对象引用传递给Client类
                clients.add(c);
                System.out.println("a client connected!");
                new Thread(c).start();  //启用独立的线程接收客户端的消息
            }
        } catch (IOException e) {
            System.out.println("网络连接失败！");
        } finally {
            try {
                ss.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    class Client implements Runnable {
        private Socket s = null;
        private DataInputStream dis = null;
        private DataOutputStream dos = null;
        private boolean bConnected = false;

        Client(Socket s) {
            this.s = s;
            try {
                dis = new DataInputStream(s.getInputStream());
                dos = new DataOutputStream(s.getOutputStream());
                bConnected = true;

            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void send(String str){
            try {
                dos.writeUTF(str);//发送消息
            } catch (IOException e) {
                clients.remove(this);
                //e.printStackTrace();
            }
        }

        public void run() {
            try {
                while (bConnected) {
                    String str = dis.readUTF();//接收消息
                    System.out.println(str);
                    for(int i = 0;i < clients.size(); i++) {
                        Client c = clients.get(i);
                        c.send(str);
                    }
                }
            } catch (EOFException e) {
                System.out.println("Client closed!");
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (dis != null)    dis.close();
                    if(dos != null) dos.close();
                    if (s != null)  s.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

客户端

 

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.Socket;
import java.net.SocketException;
import java.net.UnknownHostException;

public class ChatClient extends Frame {
    private DataOutputStream dos = null;
    private DataInputStream dis = null;
    private boolean bConnected = false;
    Socket s = null;

    private TextField tfText = new TextField();
    private TextArea caContent = new TextArea();
    Thread tRecv = new Thread(new Receive());//接收消息的线程

    public static void main(String[] args) {
        new ChatClient().frameLaunch();
    }

    private void frameLaunch() {

        this.setLocation(500, 500);

        tfText.addActionListener(new TFListener());
        add(tfText, BorderLayout.SOUTH);
        add(caContent, BorderLayout.NORTH);
        // this.setSize(400,200);   --与pack（）同时使用时无效
        pack();

        this.addWindowListener(new WindowAdapter() {//关闭窗口
            public void windowClosing(WindowEvent arg0) {
                disConnected();//关闭窗口前先关闭连接
                System.exit(0);
            }
        });

        setVisible(true);
        connected();
        tRecv.start();
    }

    public void connected() {
        try {
            s = new Socket("127.0.0.1", 8888);
            dos = new DataOutputStream(s.getOutputStream());
            dis = new DataInputStream(s.getInputStream());
            bConnected = true;//标记已连接上
            System.out.println("connected successfully!");

        } catch (UnknownHostException e) {
            System.out.println("服务器未启动！");
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void disConnected() {
        /*
        try {
            bConnected = false;
            tRecv.join();           //在Receive中仍然可能陷入死循环
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            try {
                dos.close();
                dis.close();
                s.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        */
        try {
            dos.close();
            dis.close();
            s.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private class TFListener implements ActionListener {//内部类，不需要外部调用

        public void actionPerformed(ActionEvent e) {
            String str = tfText.getText().trim();
            tfText.setText("");
            sendMessage(str);
        }
    }

    private void sendMessage(String str) {
        try {
            dos.writeUTF(str);
            dos.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class Receive implements Runnable {
        public void run() {
            try {
                while(bConnected){
                    String str = dis.readUTF();
                    System.out.println(str);
                    caContent.setText(caContent.getText() + str + "\n");
                }

            } catch (SocketException e) {
                System.out.println("退出了，bye!");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}