package com.jxkj.udp.client;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Arrays;

import org.apache.log4j.Logger;

import com.jxkj.util.Util;
/**
 * 发送UDP数据
 * @author sourcezero
 *
 */
public class UdpClient {
    private static Logger logger = Logger.getLogger(UdpClient.class);
    private static String ip="127.0.0.1";//发向地址
    private static int port=9999;//发向端口
    private static int sleep = 2;//休眠时间 
    
    
    public static void main(String[] args)  {
        DatagramSocket client = null;
        byte[] sendBuf;
        if(args!=null&&args.length>0){
            port = Integer.valueOf(args[0]);
        }
        try {
            System.out.println("启动UDP发送程序：发送端口"+port);
            StringBuffer contents = new StringBuffer();
            contents.append("测试UDP中文广播");
            contents.append("ok");
            client = new DatagramSocket(50000);
            byte[] headbt = hexStringToByte(getUdpHead(contents.length()*4,1,1,1));
            byte[] bodybt =  Util.string2Hex(contents.toString(), 4).getBytes();
            sendBuf = addBytes(headbt,bodybt);
            
            InetAddress addr = InetAddress.getByName(ip);
            DatagramPacket sendPacket 
                = new DatagramPacket(sendBuf ,sendBuf.length , addr , port);
            while(true){
                client.send(sendPacket);
                System.out.println(Arrays.toString(sendPacket.getData()));
                try {
                    Thread.sleep(sleep*1000);
                } catch (InterruptedException e) {
                    logger.error(e);
                }
            }
        } catch (IOException e) {
            logger.error(e);
        } finally{
            if(client!=null){
                client.close();
            }
        }
    }
    
    /**
     * 
     * @param total   报文长度
     * @param count   数据个数
     * @param start   起始地址
     * @param tbType  对应表类型
     * @return
     */
    public static String getUdpHead(int total,int count,int start,int tbType){
        StringBuffer sb = new StringBuffer();
        String hexTotal = addZeroForNum(Integer.toHexString(total).toUpperCase(),4);
        String hexCount = addZeroForNum(Integer.toHexString(count).toUpperCase(),4);
        String hexStart = addZeroForNum(Integer.toHexString(start).toUpperCase(),4);
        String hexTbType = addZeroForNum(Integer.toHexString(tbType).toUpperCase(),4);
        //启动字符          发送站地址           报文长度
        sb.append("68").append("01").append(hexTotal);
         
        //数据类型        数据个数1个     起始地址1
        sb.append("10").append(hexCount).append(hexStart);
        //对应表类型
        sb.append(hexTbType);
        return sb.toString();
    }
     

    public static byte[] hexStringToByte(String hex) {
        int len = (hex.length() / 2);
        byte[] result = new byte[len];
        char[] achar = hex.toCharArray();
        for (int i = 0; i < len; i++) {
            int pos = i * 2;
            result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
        }
        return result;
    }

    private static int toByte(char c) {
        byte b = (byte) "0123456789ABCDEF".indexOf(c);
        return b;
    }
    
    
    public static byte[] addBytes(byte[] data1, byte[] data2) {  
        byte[] data3 = new byte[data1.length + data2.length];  
        System.arraycopy(data1, 0, data3, 0, data1.length);  
        System.arraycopy(data2, 0, data3, data1.length, data2.length);  
        return data3;  
    } 
    /**
     * 左补0
     * 
     * @param str
     * @param strLength
     * @return
     */
    public static String addZeroForNum(String str, int strLength) {
        int strLen = str.length();
        if (strLen < strLength) {
            while (strLen < strLength) {
                StringBuffer sb = new StringBuffer();
                sb.append("0").append(str);// 左补0
                // sb.append(str).append("0");//右补0
                str = sb.toString();
                strLen = str.length();
            }
        }
        return str;
    }
}