[javaSE] 网络编程（UDP通信）_java

概述UDP发送端获取DatagramSocket对象，new出来获取DatagramPacket对象，new出来，构造参数：byte[]数组，int长度，InetAddress对象，int端口调用D

UDP发送端

获取DatagramSocket对象，new出来

获取DatagramPacket对象，new出来，构造参数：byte[]数组，int长度，InetAddress对象，int端口

调用DatagramSocket对象的send()方法，发送出去，参数：DatagramPacket对象

调用DatagramSocket对象的close()方法，关闭资源

import java.net.DatagramPacket; java.net.DatagramSocket; java.net.InetAddress;/** * 发送端 * @author taoshihan * */public class Sender {    static voID main(String[] args) throws Exception {        DatagramSocket ds=new DatagramSocket();        byte[] buf="Hello UDP".getBytes();        DatagramPacket p=new DatagramPacket(buf,buf.length,InetAddress.getLocalHost(),10000);        ds.send(p);        ds.close();    }}

UDP接收端

获取DatagramSocket对象，new出来，构造参数：int端口号

获取DatagramPacket对象，new出来，构造参数：byte[]数组，int长度

调用DatagramSocket对象的receive()方法，接收数据，参数：DatagramPacket对象

调用DatagramPacket对象的getAddress()方法，获取到InetAdress对象

调用DatagramPacket对象的getData()方法，获取到byte[]字节数组，接收的数据

调用DatagramPacket对象的getLength()方法，获取到数据长度

通过new String()包一下，获得String数据，参数：byte[]数组，0开始，length长度

 * 接收端 *  Receiver {    new DatagramSocket(10000);        byte[] buf=new byte[1024];        DatagramPacket datagramPacket= DatagramPacket(buf,buf.length);        ds.receive(datagramPacket);                InetAddress ip= datagramPacket.getAddress();        int port=datagramPacket.getPort();        byte[] resByte=datagramPacket.getData();        int length=datagramPacket.getLength();                String info=new String(resByte,0,length);        System.out.println("来自："+ip.getHostAddress()+":"+port+"说："+info);            }}