客服端響應(yīng)服務(wù)端時(shí)數(shù)據(jù)報(bào)創(chuàng)建不用傳IP和端口嗎？ 為什么是DatagramPacket packe2=new DatagramPacket(data, data.length);

而不是這樣寫呢？DatagramPacket packet=new DatagramPacket(data, data.length, address, port);

=====================================

public class UDPClient {

public static void main(String[] args) throws IOException {

/*

* 向服務(wù)器端發(fā)送數(shù)據(jù)

*/

//1.定義服務(wù)器的地址、端口號(hào)、數(shù)據(jù)

InetAddress address=InetAddress.getByName("localhost");

int port=8800;

byte[] data="用戶名：admin;密碼：123".getBytes();

//2.創(chuàng)建數(shù)據(jù)報(bào)，包含發(fā)送的數(shù)據(jù)信息

DatagramPacket packet=new DatagramPacket(data, data.length, address, port);

//3.創(chuàng)建DatagramSocket對(duì)象

DatagramSocket socket=new DatagramSocket();

//4.向服務(wù)器端發(fā)送數(shù)據(jù)報(bào)

socket.send(packet);

/*

* 接收服務(wù)器端響應(yīng)的數(shù)據(jù)

*/

//1.創(chuàng)建數(shù)據(jù)報(bào)，用于接收服務(wù)器端響應(yīng)的數(shù)據(jù)

byte[] data2=new byte[1024];

DatagramPacket packet2=new DatagramPacket(data2, data2.length);

//2.接收服務(wù)器響應(yīng)的數(shù)據(jù)

socket.receive(packet2);

//3.讀取數(shù)據(jù)

String reply=new String(data2, 0, packet2.getLength());

System.out.println("我是客戶端，服務(wù)器說："+reply);

//4.關(guān)閉資源

socket.close();