最近在看Socke相關的東西，因為平時工作中用到這塊的東西比較少，記錄一下，以後可以回顧一下。

UDP協議只管傳送資料，不論服務端是否正常執行，都會發送，其特點是：效率高、不安全、容易丟包。

廢話不多說，直接上程式碼

客戶端：

package com.tz.socket.client;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

/**
 * <p> Title: AskClient </p>
 * <p> Description: 資料傳送方</p>
 * <p> Company: </p>
 * @author UU
 * @date 2017年6月28日下午9:29:36
 */
public class AskClient {
	
	private static final int SERVER_PORT = 8888;
	private static final int CLIENT_PORT = 6666;

	public static void main(String[] args) throws Exception {
		
		//建立套接字物件(自己的埠)
		DatagramSocket socket = new DatagramSocket(SERVER_PORT);
//		String msg = "在嗎？";
		//獲取控制檯輸入資訊
		Scanner scanner = new Scanner(System.in);
		
		while (true) {
			String msg = scanner.nextLine();
			DatagramPacket packet = new DatagramPacket(msg.getBytes(), msg.getBytes().length,
					InetAddress.getLocalHost(), CLIENT_PORT);
			//傳送
			socket.send(packet);
			
			if ("88".equals(msg)) {
				break;
			}
			
			//接受服務端傳送的資訊
			byte[] b = new byte[1024];
			DatagramPacket packet2 = new DatagramPacket(b, b.length, InetAddress.getLocalHost(), CLIENT_PORT);
			socket.receive(packet2);
			System.out.println("小明："+new String(b,0,packet2.getLength()));
		}
		
		socket.close();
	}
}
 

package com.tz.socket.server;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

/**
 * 接受方
 * <p> Title: AskServer </p>
 * <p> Description: </p>
 * <p> Company: </p>
 * @author UU
 * @email 
 
[email protected]
 * @phone 18317183091
 * @date 2017年6月28日下午10:24:42
 */
public class AskServer {
	
	private static final int SERVER_PORT = 6666;
	private static final int CLIENT_PORT = 8888;

	public static void main(String[] args) throws Exception {
		
		//建立套接字物件(自己的埠)
		DatagramSocket server = new DatagramSocket(SERVER_PORT);
		
		Scanner scanner = new Scanner(System.in);
		while(true){
			
			//接受資料包，並讀進陣列b中
			byte[] b = new byte[1024];
			DatagramPacket packet = new DatagramPacket(b, b.length,InetAddress.getLocalHost(),CLIENT_PORT);
			
			server.receive(packet);
			
			System.out.println("小紅："+new String(b,0,packet.getLength()));
			
//			String callBack = "在的！";
			String callBack = scanner.nextLine();
			DatagramPacket packet2 = new DatagramPacket(callBack.getBytes(), callBack.getBytes().length,
					InetAddress.getLocalHost(),CLIENT_PORT);
			server.send(packet2);
			
			if ("88".equals(callBack)) {
				break;
			}
		}
		server.close();
	}
}