A：创建发送端socket对象；
B：创建数据，并把数据打包；
C：调用socket对象的发送方法发送数据包；
D：释放资源
package net;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class SendDemo {
public static void main(String[] args) throws IOException {
//A
DatagramSocket ds = new DatagramSocket();
//B
byte[] by = "Hello,UDP".getBytes();
int length = by.length;
InetAddress addr = InetAddress.getByName("192.168.1.22");
int port = 10010;
DatagramPacket dp = new DatagramPacket(by, length, addr, port);
//C
ds.send(dp);
//D
ds.close();
}
}
A：创建接收端socket对象；
B：创建一个数据包（接收容器）；
C：调用socket对象的接收方法接收数据；
D：解析数据，显示到控制台；
E：释放资源
package net;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class ReceiveDemo {
public static void main(String[] args) throws IOException {
//A
DatagramSocket ds = new DatagramSocket(10010);
//B
byte[] by = new byte[1024];
int length = by.length;
DatagramPacket dp = new DatagramPacket(by, length);
//C
ds.receive(dp);
//D
//获取对方ip
InetAddress addr = dp.getAddress();
String ip = addr.getHostAddress();
byte[] by2 = dp.getData();
int len = by2.length;
String s = new String(by2, 0, len);
System.out.println(ip+"发送的数据是："+s);
//E
ds.close();
}
}
先运行接收端代码，再运行发送端代码。
package net;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class SendDemo {
public static void main(String[] args) throws IOException {
//A
DatagramSocket ds = new DatagramSocket();
//数据来自键盘录入
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = null;
while((line = br.readLine()) != null){
//当输入jieshu时，结束
if("jieshu".equals(line)){
break;
}
//B
byte[] by = line.getBytes();
int length = by.length;
InetAddress addr = InetAddress.getByName("192.168.1.22");
int port = 10010;
DatagramPacket dp = new DatagramPacket(by, length, addr, port);
//C
ds.send(dp);
}
//D
ds.close();
}
}
package net;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class ReceiveDemo {
public static void main(String[] args) throws IOException {
//A
DatagramSocket ds = new DatagramSocket(10010);
//多次接受版本
while(true){
//B
byte[] by = new byte[1024];
int length = by.length;
DatagramPacket dp = new DatagramPacket(by, length);
//C
ds.receive(dp);
//D
//获取对方ip
InetAddress addr = dp.getAddress();
String ip = addr.getHostAddress();
byte[] by2 = dp.getData();
int len = by2.length;
String s = new String(by2, 0, len);
System.out.println(ip+"发送的数据是："+s);
}
//E
//ds.close();
}
}
