【Java】网络编程UDP 实现多线程在线聊天

红太狼 2023-02-26 01:05 47阅读 0赞

上一篇博客通过UDP实现了聊天，但只能单方面发送消息，这次实现了多线程在线聊天，也就是可以双方互发消息。

**发送消息：**

package com.kuang.chat;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.net.DatagramPacket;
    import java.net.DatagramSocket;
    import java.net.InetSocketAddress;
    import java.net.SocketException;
    
    public class TalkSend implements Runnable { 
        DatagramSocket socket = null;
        BufferedReader reader = 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(fromPort);
                reader = new BufferedReader(new InputStreamReader(System.in));
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }
    
        @Override
        public void run() { 
            while (true) { 
                try { 
                    String data = reader.readLine();
                    byte[] datas = data.getBytes();
                    DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(this.toIP,this.toPort));
    
                    socket.send(packet);
                    if (data.equals("bye")) { 
                        break;
                    }
                } catch (IOException e) { 
                    e.printStackTrace();
                }
            }
            socket.close();
        }
    }

**接收消息：**

package com.kuang.chat;
    
    import java.io.IOException;
    import java.net.DatagramPacket;
    import java.net.DatagramSocket;
    import java.net.SocketException;
    
    public class TalkReceive implements Runnable { 
        DatagramSocket socket = null;
        private int port;
        private String msgFrom;
    
        public TalkReceive(int port,String msgFrom) { 
            this.port = port;
            this.msgFrom = msgFrom;
            try { 
                socket = new DatagramSocket(port);
            } catch (SocketException e) { 
                e.printStackTrace();
            }
        }
    
        @Override
        public void run() { 
    
            while (true) { 
                try { 
                    //准备接收数据
                    byte[] container = new byte[1024];
                    DatagramPacket packet = new DatagramPacket(container,0,container.length);
                    socket.receive(packet);//阻塞式接受包裹
    
                    //断开连接 bye
                    byte[] data = packet.getData();
                    String receiveData = new String(data,0,data.length);
    
                    System.out.println(msgFrom + ":" +receiveData);
                    if (receiveData.equals("bye")) { 
                        break;
                    }
                } catch (IOException e) { 
                    e.printStackTrace();
                }
            }
            socket.close();
        }
    }

**用户1：学生**

package com.kuang.chat;
    
    public class TalkStudent { 
        public static void main(String[] args) { 
            //开启两个线程
            new Thread(new TalkSend(7777,"localhost",9999)).start();
            new Thread(new TalkReceive(8888,"老师")).start();
        }
    }

**用户2：老师**

package com.kuang.chat;
    
    public class TalkTeacher { 
        public static void main(String[] args) { 
            new Thread(new TalkSend(5555,"localhost",8888)).start();
            new Thread(new TalkReceive(9999,"学生")).start();
        }
    }

**运行结果：**

1、启动学生端，开始运行  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70]

2、启动教师端，开始运行  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70 1]

3、学生发送消息，教师收到  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70 3]  
4、教师发送消息，学生收到  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70 4]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDY2ODg5OA_size_16_color_FFFFFF_t_70 5]

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