生产uuid

uuid生产功能

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近端时间要做一个获取唯一流水号的功能，于是有了：ip+starttime+pid+flow的方式。

import java.lang.management.ManagementFactory;
import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.atomic.AtomicLong;

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

/**
 * 获取流水号：ip+starttime+pid+flow
 * 
 * //将ip和starttime和pid转化为32进制+流水号
 * 
 * @author zhanghw
 */
public class FlowNum {
    private static final Logger LOGGER = LoggerFactory.getLogger(FlowNum.class);
    private static final String FLOW_NUM_PERFIX;// 流水号前缀
    private static final AtomicLong count = new AtomicLong();
    private static final int radix = 32;// 转换的进制
    private static final DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd-HH:mm:ss-SSS");

    static {
        String ip = getLocalAddress();
        long startTime = System.currentTimeMillis();
        String pid = getPid();
        System.out.printf("ip=%s,pid= %s,startTime= %s", ip, pid, dateFormat.format(new Date(startTime)));
        LOGGER.info("this program ip ={},pid={},starttime={}", ip, pid, dateFormat.format(new Date(startTime)));

        StringBuilder sb = new StringBuilder();
        sb.append(ipToLong(ip)).append(startTime).append(pid);
        // ip(9),starttime(),pid
        System.out.println(sb.toString());

        BigInteger big = new BigInteger(sb.toString());
        String str_32 = big.toString(radix);
        FLOW_NUM_PERFIX = str_32 + "_";
    }

    /**
     * 获取一个流水号
     * @return
     */
    public static String get() {
        return FLOW_NUM_PERFIX + count.incrementAndGet();
    }

    /**
     * 47igkn0n9v03282b9dr8_7
     * 
     * @throws Exception
     */
    public static void printInfo(String FLOW_NUM_PERFIX) throws Exception {
        if (FLOW_NUM_PERFIX == null || FLOW_NUM_PERFIX.trim().length() == 0) {
            throw new Exception("the sttring is empty!");
        }
        String perfix = FLOW_NUM_PERFIX.split("_")[0];
        BigInteger perfix_32 = new BigInteger(perfix, radix);// 32进制
        String perfix_10 = perfix_32.toString(10);// 10进制

        String ip_long = perfix_10.substring(0, 9);
        String startTime = perfix_10.substring(9, 22);
        System.out.println(startTime);
        String pid = perfix_10.substring(22, perfix_10.length());

        String ipStr = longToIp(Long.valueOf(ip_long));
        String startTimeStr = dateFormat.format(new Date(Long.valueOf(startTime)));

        System.out.printf("ip=%s,time=%s,pid=%s", ipStr, startTimeStr, pid);
        LOGGER.info("ip={},time={},pid={}", ipStr, startTimeStr, pid);

    }

    /**
     * 获取当前进程id
     * 
     * @return
     */
    private static final String getPid() {
        // get name representing the running Java virtual machine.
        String name = ManagementFactory.getRuntimeMXBean().getName();
        String pid = name.split("@")[0];
        return pid;
    }

    /**
     * 获取当前服务器ip
     * 
     * @return
     */
    private static final String getLocalAddress() {
        InetAddress addr = null;
        try {
            addr = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }

        if (addr == null) {
            return null;
        }

        return addr.getHostAddress();
    }

    /**
     * long转为ip
     * 
     * @param ip
     * @return
     */
    private static String longToIp(long ip) {
        return ((ip >> 24) & 0xFF) + "." + ((ip >> 16) & 0xFF) + "." + ((ip >> 8) & 0xFF) + "." + (ip & 0xFF);
    }

    /**
     * ip转为long
     * 
     * @param ipAddress
     * @return
     */
    private static long ipToLong(String ipAddress) {
        long result = 0;
        String[] ipAddressInArray = ipAddress.split("\.");
        for (int i = 3; i >= 0; i--) {
            long ip = Long.parseLong(ipAddressInArray[3 - i]);
            result |= ip << (i * 8);
        }
        return result;
    }

}