在UDPsend.java中,DatagramSocket ds = new DatagramSocket();
在一个端口上创建,然后向3000端口发送消息,消息由DatagramPacket进行封装发送。
在UDPreceive.java中,在3000端口建立Datasocket,接收信息,根据getPort()方法得到发送来的信息的端口,再向该端口发送信息
public class UDPsend {
public static void main(String...args) throws Exception{
String str = "hello world";
//向3000端口发送消息
DatagramSocket ds = new DatagramSocket();
DatagramPacket dp = new DatagramPacket(str.getBytes(),str.length(), InetAddress.getByName("127.0.0.1"),3000);
System.out.println("我要发送");
ds.send(dp);
Thread.sleep(1000);
System.out.println("我要接受");
byte [] bt = new byte[1024];
DatagramPacket dpl = new DatagramPacket(bt,1024);
ds.receive(dpl);
System.out.println(new String(dpl.getData(),0,dpl.getLength()));
}
}
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UDPreceive {
public static void main(String...args) throws Exception{
DatagramSocket ds = new DatagramSocket(3000);
byte [] bt = new byte[1024];
DatagramPacket dpl = new DatagramPacket(bt,1024);
System.out.println("我要接受");
ds.receive(dpl);
String str = new String(dpl.getData(),0,dpl.getLength());
System.out.println(str);
Thread.sleep(1000);
System.out.println("我要发送");
str+="22";
DatagramPacket dp = new DatagramPacket(str.getBytes(),
str.length(), InetAddress.getByName("127.0.0.1"),dpl.getPort());//dp.getPort();得到端口
ds.send(dp);
ds.close();
}
}