java UDP如何实现一个聊天工具 java UDP实现一个聊天工具代码示例

java UDP如何实现一个聊天工具？本篇文章小编给大家分享一下java UDP实现一个聊天工具代码示例，文章代码介绍的很详细，小编觉得挺不错的，现在分享给大家供大家参考，有需要的小伙伴们可以来看看。

题目：

假设Tom和Jerry利用Java UDP进行聊天，请为他们编写程序。具体如下：

（1）、Tom和Jerry聊天的双方都应该具有发送端和接收端；

（2）、利用DatagramSocket与DatagramPacket；

（3）、实现 java.lang.Runnable类，重写 run()方法。

学过计网的都知道，利用三元组（ip地址，协议，端口）就可以标识网络的进程了。

而进行通信我们直接运用socket就可以了，首先需要知道是socket是什么，这部分可以参考这个大佬写的博客。

https://www.jb51.net/article/121601.htm

实现一个客户端，那么需要Tom和Jerry都可以实现接收和发送功能，分别用两个线程启动。

接收线程Receive_Thread.java

package Chat_UDP;

import java.io.IOException;
import java.util.Date;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.text.SimpleDateFormat;

public class Receive_Thread extends Thread {
 private static final int MAX_RECEIVE_BUFFER = 1024;
 private DatagramSocket server;
 private DatagramPacket packet;
 byte[] buffer = new byte[MAX_RECEIVE_BUFFER];
 
 public Receive_Thread(DatagramSocket server)
 {
  this.server = server;
  packet = new DatagramPacket(buffer, buffer.length);
 }
 
 @Override
 public void run() {
  try
  {
   while(true)
   {
    //接收数据包
    server.receive(packet);
    String s = new String(packet.getData(),packet.getOffset(),packet.getLength(),"UTF-8");
    Date day=new Date(); 
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
    if(packet.getPort() == 10001)
    	System.out.println("Tom"+packet.getAddress()+" 说:"+s+"t"+df.format(day));
    else{
    	System.out.println("Jerry"+packet.getAddress()+" 说 :"+s+"t"+df.format(day));
    }
    packet.setLength(buffer.length);
   }
  }
  catch(IOException e)
  {
   System.out.println("IOException");
  }
 }
}

发送线程Send_Thread.java

package Chat_UDP;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.Scanner;

public class Send_Thread extends Thread{
 //发送的socket端
 private DatagramSocket sender = null;
 //待发送的目标地址
 private InetSocketAddress address = null;
 //从键盘输入
 Scanner scan = new Scanner(System.in);
 public Send_Thread(DatagramSocket sender,InetSocketAddress address)
 {
  this.sender = sender;
  this.address = address;
 }
 
 @Override
 public void run() {
  // TODO Auto-generated method stub
  try
  {
   while(true)
   {
    //输入待发送的内容
    String input = scan.nextLine();
    if(input.equals("exit"))
     break;
    byte[] data = null;
    data = input.getBytes("UTF-8");
    //创建UDP数据报
    DatagramPacket pack = new DatagramPacket(data, data.length,address);
    sender.send(pack); 
   }
   System.out.println("Exit!");
   
  }catch(IOException e)
  {
   System.out.println("IOException");
  }
 }

}

聊天服务器

Chat_Server.java

package Chat_UDP;
//杨丽冰 201831064402
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class Chat_Server {

 private static final int DEST_PORT = 8888;
 private static final int SEND_PORT = 10001;
 private static final int RECE_PORT = 9000;
 private static final String IP = "127.0.0.1";

 public static void main(String[] args)
 {
  try{
   Send_Thread send_thread = null;
   Receive_Thread rece_thread = null;
   InetSocketAddress address = null;
   //创建待接受数据包的目的机的端口号和IP地址
   address = new InetSocketAddress(IP, DEST_PORT);
   //创建发送的Socket端
   DatagramSocket sendsocket = new DatagramSocket(SEND_PORT);
   //创建接受的Socket端
   DatagramSocket recesocket = new DatagramSocket(RECE_PORT);
   //发送线程建立
   send_thread = new Send_Thread(sendsocket, address);
   //接受线程的建立
   rece_thread = new Receive_Thread(recesocket);
   send_thread.start();
   rece_thread.start();
  }catch(Exception e)
  {
   System.out.println("Exception!");
  }

 }

}

聊天客户端 Chat_Client.java

package Chat_UDP;
//杨丽冰 201831064402
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class Chat_Client {
	//声明端口号
 private static final int DEST_PORT = 9000;
 private static final int SEND_PORT = 10000;
 private static final int RECE_PORT = 8888;
 private static final String IP = "127.0.0.1";

 public static void main(String[] args)
 {
  try{
   Send_Thread send_thread = null;
   Receive_Thread rece_thread = null;
   InetSocketAddress address = null;
   //创建待接受数据包的目的机的端口号和IP地址
   address = new InetSocketAddress(IP, DEST_PORT);
   //创建发送的Socket端
   DatagramSocket sendsocket = new DatagramSocket(SEND_PORT);
   //创建接受的Socket端
   DatagramSocket recesocket = new DatagramSocket(RECE_PORT);
   //发送线程建立
   send_thread = new Send_Thread(sendsocket, address);
   //接受线程的建立
   rece_thread = new Receive_Thread(recesocket);
   send_thread.start();
   rece_thread.start();

  }catch(Exception e)
  {
   System.out.println("Exception!");
  }

 }

}

需要注意的时候运行的时候需要同时运行聊天服务器和客户端，才能够正常运行。

最终效果如下：