Java--UDP通信（单向）
Send(发送方):
import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.net.SocketException;public class SendDemo1 {private static final int PORT = 8080;private static final String IP = "localhost";public static void main(String[] args) {sendHandler();}private static void sendHandler(){DatagramSocket sendSocket = null;try {while(true){//创建套接字sendSocket = new DatagramSocket();//键盘录入BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String send = br.readLine();byte[] buf = send.getBytes();//设定数据包内容，长度，发送到的地址和端口DatagramPacket dp = new DatagramPacket(buf, buf.length, InetAddress.getByName(IP), PORT);//发送数据包sendSocket.send(dp);}} catch (SocketException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}finally{if(sendSocket != null){sendSocket.close();}}}}
Receive(接收方)：
import java.io.IOException;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.SocketException;public class ReceiverDemo1 {private static final int PORT = 8080;public static void main(String[] args) {receiveHandler();}private static void receiveHandler() {DatagramSocket receiveSocket = null;try {//在8080端口监听receiveSocket = new DatagramSocket(PORT);//while循环，一直在等待接收数据while(true){//创建一个包，并接收数据byte[] buf = new byte[1024];DatagramPacket dp = new DatagramPacket(buf, buf.length);receiveSocket.receive(dp);//取得IP地址和包里的数据内容String ip = dp.getAddress().getHostAddress();String data = new String(dp.getData(), 0, dp.getLength());System.out.println(ip + ":" + data);}} catch (SocketException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}finally{if(receiveSocket != null){receiveSocket.close();}}}}
先启动接收方，再启动发送方