Java 实现基于UDP的用户登录

package JavaLearn.UDP;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;

/**
* Created by ChenHe on 2017/2/21.
* 客户端
*/

public class UdpClient {
public static void main(String[] atrs) throws IOException {
/**
* 向服务端发送数据
* **/

//1.定义服务器的地址，端口号，数据
InetAddress address = InetAddress.getByName("localhost");
int port = 8800;
byte[] data = "用户名：admin；密码：123".getBytes();
//2.创建数据报，包含发送的信息
DatagramPacket packet = new DatagramPacket(data,data.length,address,port);
//3.创建DatagramSocket对象
DatagramSocket socket = new DatagramSocket();
//4.向服务器端发送数据报
socket.send(packet);
/**
* 接收服务端的返回数据
* */

//1.创建数据报，用于接收服务器端响应数据
byte[] data2 = new byte[1024];
DatagramPacket packet2 = new DatagramPacket(data2,data2.length);
//2.接收服务器响应的数据
socket.receive(packet2);
//3.读取数据
String reply = new String(data2,0,packet2.getLength());
System.out.println("我是客户端，服务器说："+reply);
//4.关闭资源
socket.close();
}
}

package JavaLearn.UDP;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

/**
* Created by ChenHe on 2017/2/21.
* 服务器端，实现基于UDP的用户登录
*/

public class UdpServer {
public static void main(String[] args) throws IOException {
/**
* 服务端接收客户端数据
* **/

//1.创建服务端DatagramSocket，指定端口
DatagramSocket socket = new DatagramSocket(8800);
//2.创建数据报，用于接收客户端发送的数据
byte[] data = new byte[1024];//创建字节数组，指定接收的数据包大小
DatagramPacket packet = new DatagramPacket(data,data.length);
//3.接收客户端发送的数据
System.out.println("******服务器端已经启动，等待客户端连入******");
socket.receive(packet);//此方法在接收到数据报之前会一直阻塞
//4.读取数据
String info = new String(data,0,packet.getLength());
System.out.println("我是服务器，客户端说："+info);

/**
* 服务端响应客户端
* **/
//1.定义客户端地址，端口号，数据
InetAddress address = packet.getAddress();
int port = packet.getPort();
byte[] data2 = "欢迎您！".getBytes();
//2.创建数据报，包含响应的数据信息
DatagramPacket packet2 = new DatagramPacket(data2,data2.length,address,port);
//3.响应客户端
socket.send(packet2);
//4.关闭socket
socket.close();
}
}