package com.jxkj.udp.server;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;

import com.jxkj.util.Util;
/**
 * 接收UDP数据
 * @author sourcezero
 *
 */
public class UdpServer {
    private static Logger logger = Logger.getLogger(UdpServer.class);
    private static int port = 9999;
    public static byte start_flag = (byte) 0x68;
    public static void main(String[] args) {
        DatagramSocket ds = null;
        try {
            if(args!=null&&args.length>0){
                port = Integer.valueOf(args[0]);
            }
            logger.info("开始监听端口 " + port + " 的数据...");
            InetAddress addr = InetAddress.getLocalHost();
            InetSocketAddress socketAddress = new InetSocketAddress(port);
            ds = new DatagramSocket(socketAddress);
            logger.info("主机名：" + addr.getHostName() + ", ip地址：" + addr.getHostAddress());
            //ds.setSoTimeout(600 * 1000);
            ds.setSoTimeout( 3000);//阻塞等待时长
            
            while (true) {
                byte[] buffer = new byte[65*1024];
                DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
                try{
                    ds.receive(packet);// 17313 3072
                    logger.info("接收到来自ip:"+packet.getAddress()+",端口为"+packet.getPort()+"的数据");
                    byte[] data = packet.getData();
                    if(data.length>0){
                        List<byte[]>  list = splitMessage(data);
                        for (byte[] bs : list) {
                            String content = Util.hexDecode(hex2String(toHexString(bs)));
                             System.out.println(content);
                        }
                    }
                }catch(SocketTimeoutException ste){
                    //logger.error("接收UDP数据超时...");
                }catch(Exception e){
                    logger.error("接收UDP出错...",e);
                }
            }

        } catch (IOException e) {
            logger.error(e);
        }finally{
            if(ds!=null){
                ds.close();
            }
        }
    }
    public static String hex2String(String hex) {

        StringBuilder sb = new StringBuilder();
        StringBuilder temp = new StringBuilder();

        // 49204c6f7665204a617661 split into two characters 49, 20, 4c...
        for (int i = 0; i < hex.length() - 1; i += 2) {

            // grab the hex in pairs
            String output = hex.substring(i, (i + 2));
            // convert hex to decimal
            int decimal = Integer.parseInt(output, 16);
            // convert the decimal to character
            sb.append((char) decimal);

            temp.append(decimal);
        }

        return sb.toString();
    }
    public static String toHexString(byte[] buf) {
        String hex = "";
        if (buf == null)
            return hex;
        for (int i = 0; i < buf.length; i++) {
            hex += toHexString(buf[i]);
        }
        return hex;
    }
    
    public static List<byte[]> splitMessage(byte[] message) {

        List<byte[]> list = new ArrayList<byte[]>();
        int len = 0;
        for (int i = 0; i < message.length;) {
            // 以68为标识进行切分
            if (message[i] == start_flag) {
                // 发送站端地址
                logger.debug("发送站端地址:"
                        + asUnsignedByte(message[1]));
                // 报文长度
                len = valueOf2byte(message[i + 2],message[i + 3]);
                logger.debug("报文长度:"+len);
                if (len > 0) {
                    byte[] submessage = new byte[len];
                    for (int k = 0; k < len; k++) {
                        int tmp =11+k;
                         
                        submessage[k] = message[tmp];
                    }
                    list.add(submessage);
                    //  校验码为unsigned short类型,生成方式为从启动字符开始至报文体结束的unsigned char
                    // 的算术累加和，进位位丢弃。
//                  log.debug("校验码："+ByteUtil.bytesToShort(message,len+4));
                    i += len + 11;
                    
                }
            }
            i++;
        }
        return list;
    }
    
    /**
     * @param hight 高位
     * @param low 低位
     * @return int
     */
    public static int valueOf2byte(byte low, byte hight) {
        String value = toHexString(low) + toHexString(hight);
        return Integer.parseInt(value, 16);
    }
    
    public static int asUnsignedByte(byte b) {
        return Integer.parseInt(toHexString(b), 16);
    }
    /**
     * 将字节转换为用16进表示的字符串
     * 
     * @param buf
     *            byte
     * @return String
     */
    public static String toHexString(byte b) {
        String s = Integer.toHexString(b);
        if (s.length() == 1) {
            s = "0" + s;
        } else if (s.length() > 2) {
            s = s.substring(s.length() - 2);
        }
        return s;
    }
    
    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;  
      
    }  
}