Socket套接字编程

UDP

服务端

public static void main(String[] args) throws IOException {
   
        //1.新建一个DatagramSocket
        DatagramSocket socket=new DatagramSocket(9999);
        //用来指定数据包内存空间的大小
        byte[]buffer=new byte[1024];
        DatagramPacket packet=new DatagramPacket(buffer,buffer.length);
//2.等着客户端来撩
        //从此套接字接受数据包
       socket.receive(packet);//收到客户端发送的消息

       String str=new String(buffer,0,packet.getLength(),"UTF-8");
        System.out.println(str);
        
       byte[]arr="收到".getBytes("UTF-8");
       DatagramPacket data=new DatagramPacket(buffer,packet.getLength(),packet.getAddress() ,packet