Java 实现简单的UDP通信

创建服务器：

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

public class TestUDPServer {
public static void main(String args[]){
byte[] buf=new byte[1024];
DatagramPacket dp=null;
DatagramSocket ds=null;
dp=new DatagramPacket(buf,buf.length);//创建一个数据包裹，用字节数组buf来接收数据
try {
ds=new DatagramSocket(6666);//创建数据报套接字并将其绑定到6666的本机端口
} catch (SocketException e) {
e.printStackTrace();
}
while(true){
try {
ds.receive(dp);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(new String(buf,0,dp.getLength()));
}
}

}


创建客户端：
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;

public class TestUDPClient {

public static void main(String[] args) {
byte[] buf=new String("hellow").getBytes();
DatagramPacket dp=null;
try {
dp=new DatagramPacket(buf,buf.length,new InetSocketAddress("127.0.0.1",6666));
} catch (SocketException e) {
e.printStackTrace();
}
DatagramSocket ds=null;
try {
ds=new DatagramSocket(8888);
} catch (SocketException e) {
e.printStackTrace();
}
try {
ds.send(dp);
} catch (IOException e) {
e.printStackTrace();
}
ds.close();
}

}