UDP应用简例

 1  1 import java.io.IOException;
 2  2 import java.net.DatagramPacket;
 3  3 import java.net.DatagramSocket;
 4  4 import java.net.InetAddress;
 5  5 
 6  6 public class RecevieDemo {
 7  7 
 8  8     public static void main(String[] args) throws IOException {
 9  9         //创建接收对象
10 10         DatagramSocket ds = new DatagramSocket(8888);
11 11         
12 12         //创建打包用的容器
13 13         byte[] buf = new byte[1024];
14 14         
15 15         //打包操作
16 16         DatagramPacket p = new DatagramPacket(buf, buf.length);
17 17         ds.receive(p);
18 18         
19 19         //获取地址
20 20         InetAddress  address = p.getAddress();
21 21         
22 22         //接收数据
23 23         byte[] data = p.getData();
24 24         
25 25         //获取长度
26 26         int length = p.getLength();
27 27         
28 28         //输出数据
29 29         System.out.println("sender ------>" + address.getHostAddress());
30 30         System.out.println(new String(data, 0, length));
31 31         
32 32         //释放资源
33 33         ds.close();
34 34     }
35 35 }

 1 import java.io.IOException;
 2 import java.net.DatagramPacket;
 3 import java.net.DatagramSocket;
 4 import java.net.InetAddress;
 5 
 6 public class SandDemo {
 7 
 8     public static void main(String[] args) throws IOException {
 9         //创建发送对象
10         DatagramSocket ds = new DatagramSocket();
11         
12         //创建发送的数据
13         String str = "Hello, UDP, I‘m coming!";
14         
15         //字符转字节并获取长度
16         byte[] bts = str.getBytes();
17         int length = bts.length;
18         
19         //定义端口和获取IP
20         int port = 8888;
21         InetAddress address = InetAddress.getByName("LAPTOP-KP5N74R4");
22         //System.out.println(InetAddress.getLocalHost());
23         
24         //打包数据
25         DatagramPacket p = new DatagramPacket(bts, length, address,port);
26         
27         //发送数据
28         ds.send(p);
29         
30         //释放资源 
31         ds.close();
32     }
33 
34 }