UDP

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

import org.junit.Test;
//关于UDP的编程实现，UDP（不可靠的传输，但是是最快的方式）
public class TestUdp {

@Test
public void send() {
DatagramSocket ds = null;
try {
ds = new DatagramSocket();
byte[] b = "我是要发送的数据".getBytes();
//创建一个数据报，每个数据不能大于64k,每一个都记录数据信息，发送端的IP，端口号以及发送到接收端的IP和端口号
DatagramPacket pack = new DatagramPacket(b, 0, b.length,InetAddress.getByName("127.0.0.1"),8989);
ds.send(pack);
ds.close();
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(ds != null){
ds.close();
}
}
}

@Test
public void accept(){
DatagramSocket ds=null;
try {
ds = new DatagramSocket(8989);
byte[] b = new byte[1024];
DatagramPacket pack = new DatagramPacket(b, 0, b.length);
ds.receive(pack);
String str = new String (pack.getData(), 0, pack.getLength());
System.out.println(str);
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(ds != null){
ds.close();
}
}

}
}