package com.nis.util;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UdpUtils {
	
	private static final Logger logger = LoggerFactory.getLogger(TextFormatUtils.class);
	
	public static String send(String sendIp,Integer slot,int timeout) {
		String rlt = "";
		DatagramSocket ds = null;
		try {
			ds = new DatagramSocket();//通过DatagramSocket对象创建udp服务
			ds.setSoTimeout(timeout);
	//		String line = "00 06 0502 00 00 68c2"; //发送的16进制字符串
			String slotStr = slot+"";
			if(slot<10) {
				slotStr = "0"+slotStr;
			}
			String line = "00 "+slotStr+" 0502 00 00"; //发送的16进制字符串
			byte[] buf = HexUtils.hexStringToByteArray(line);
			DatagramPacket dp = new DatagramPacket(buf,buf.length,InetAddress.getByName(sendIp),6800);//发送至指定IP，指定端口
			ds.send(dp);//通过send方法将数据包发送出去
			//定义数据包,用于存储数据
			byte[] buf2 = new byte[8];
			DatagramPacket dp2 = new DatagramPacket(buf2,buf2.length);
			ds.receive(dp2);//通过服务的receive方法将收到数据存入数据包中,receive()为阻塞式方法
			//通过数据包的方法获取其中的数据
			String ip = dp2.getAddress().getHostAddress();
	        
			System.out.println(ip+"::"+HexUtils.bytesToHexString(buf2));
			
			rlt = HexUtils.bytesToHexString(buf2);
		}catch (Exception e) {
			logger.error(sendIp+"::"+slot+">>"+e.getMessage());
		}finally {
			if(ds!=null) {
				ds.close();//关闭资源
			}
		}
		return rlt;
	}
}