​Java实现人与人之间的聊天

@发送端代码
	import java.io.BufferedReader;
	import java.io.InputStreamReader;
	import java.net.DatagramPacket;
	import java.net.DatagramSocket;
	import java.net.InetAddress;
	
	public class Send_Client {<!-- -->

	    public static void main(String[] args) throws Exception{<!-- -->
	        DatagramSocket socket=new DatagramSocket();
	        while (true){<!-- -->
	            //直接从控制台中读取数据
	            BufferedReader data=new BufferedReader(new InputStreamReader(System.in));
	            String datas = data.readLine();
	            //将数据转换为可以传输的字节
	            byte[] send_data = datas.getBytes();
	            DatagramPacket packet = new DatagramPacket(send_data,0,send_data.length, new InetSocketAddress("127.0.0.1",888));
	            socket.send(packet);
	            //这里时设置他们怎么结束，可以自行展开
	            if(datas.equals("bye")){<!-- -->
	                break;
	            }
	        }
	        socket.close();
	    }
	}

	import java.net.DatagramPacket;
	import java.net.DatagramSocket;
	
	public class Receiver_Client {<!-- -->
	    public static void main(String[] args)throws Exception {<!-- -->
	        DatagramSocket socket = new DatagramSocket(888);
	        while(true){<!-- -->
	            byte[] buffer =new byte[1024];
	            DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
	            socket.receive(packet);
	            byte[] data = packet.getData();
	            String real_data = new String(data, 0, data.length);
	            real_data=real_data.trim();
	            if(real_data.equals("bye")){<!-- -->
	                break;
	            }
	            System.out.println(real_data);
	        }
	        socket.close();
	    }
	}
	
注意：接受bye时要对字符串进行去空格操作，要不然无法退出，字符串.trim()即可

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.*;

public class TalkSend implements Runnable{<!-- -->
    DatagramSocket socket=null;
    BufferedReader data=null;
    private int fromPort;
    private String toIP;
    private int toPort;

    public TalkSend(int fromPort, String toIP, int toPort) {<!-- -->
        this.fromPort = fromPort;
        this.toIP = toIP;
        this.toPort = toPort;
        try {<!-- -->
            socket=new DatagramSocket(this.fromPort);
        } catch (SocketException e) {<!-- -->
            e.printStackTrace();
        }
        data=new BufferedReader(new InputStreamReader(System.in));
    }

    @Override
    public void run() {<!-- -->
        while (true) {<!-- -->
            try {<!-- -->
                //直接从控制台中读取数据
                String datas = data.readLine();
                //将数据转换为可以传输的字节
                byte[] send_data = datas.getBytes();
                DatagramPacket packet = new DatagramPacket(send_data, 0, send_data.length, new InetSocketAddress(this.toIP,this.toPort));
                socket.send(packet);
                if (datas.equals("bye")) {<!-- -->
                    break;
                }
            }catch (Exception e){<!-- -->
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class TalkReceive implements Runnable {<!-- -->
    DatagramSocket socket=null;
    private int myPort;
    private String msg;

    public TalkReceive(int myPort,String msg) {<!-- -->
        this.myPort = myPort;
        this.msg=msg;
        try {<!-- -->
            socket = new DatagramSocket(this.myPort);
        } catch (SocketException e) {<!-- -->
            e.printStackTrace();
        }
    }

    @Override
    public void run() {<!-- -->
        while(true){<!-- -->
            try{<!-- -->
                byte[] buffer =new byte[1024];
                DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
                socket.receive(packet);
                byte[] data = packet.getData();
                String real_data = new String(data, 0, data.length);
                real_data=real_data.trim();
                if(real_data.equals("bye")){<!-- -->
                    break;
                }
                System.out.println(this.msg+":"+real_data);
            }catch (Exception e){<!-- -->
                e.printStackTrace();
            }

            }
        socket.close();
    }
}

public class Teacher {<!-- -->
    public static void main(String[] args) {<!-- -->
    new Thread(new TalkSend(5555,"127.0.0.1",9999)).start();
    new Thread(new TalkReceive(5678,"学生")).start();
    }
}

public class Student {<!-- -->
    public static void main(String[] args) {<!-- -->
        new Thread(new TalkSend(7777,"127.0.0.1",5678)).start();
        new Thread(new TalkReceive(9999,"老师")).start();
    }
}