本文实例讲述了Java实现产生随机字符串主键的UUID工具类。分享给大家供大家参考，具体如下：
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package com.gcloud.common;import java.net.InetAddress;import java.util.UUID;/** * uuid工具类 * Created by charlin on 2017/9/9. */public class UUIDUtil { private String sep = ""; private static int IP = 0; private static short counter = (short) 0; private static int JVM = (int) (System.currentTimeMillis() >>> 8); static { try { IP = toInt(InetAddress.getLocalHost().getAddress()); } catch (Exception e) { } } private static UUIDUtil instance = new UUIDUtil(); public static UUIDUtil getInstance() { return instance; } /** * byte转int * * @param bytes * @return */ public static int toInt(byte[] bytes) { int result = 0; for (int i = 0; i < 4; i++) { result = (result << 8) - Byte.MIN_VALUE + (int) bytes[i]; } return result; } protected String format(int intval) { String formatted = Integer.toHexString(intval); StringBuffer buf = new StringBuffer("00000000"); buf.replace(8 - formatted.length(), 8, formatted); return buf.toString(); } protected String format(short shortval) { String formatted = Integer.toHexString(shortval); StringBuffer buf = new StringBuffer("0000"); buf.replace(4 - formatted.length(), 4, formatted); return buf.toString(); } protected int getJVM() { return JVM; } protected synchronized short getCount() { if (counter < 0) { counter = 0; } return counter++; } protected int getIP() { return IP; } protected short getHiTime() { return (short) (System.currentTimeMillis() >>> 32); } protected int getLoTime() { return (int) System.currentTimeMillis(); } public String generate() { return new StringBuffer(36).append(format(getIP())).append(sep).append( format(getJVM())).append(sep).append(format(getHiTime())) .append(sep).append(format(getLoTime())).append(sep).append( format(getCount())).toString(); } // 得到一个序号 public static String getUUID() { String s = UUID.randomUUID().toString(); return s.substring(0, 8) + s.substring(9, 13) + s.substring(14, 18) + s.substring(19, 23) + s.substring(24); } /** * 一次得到多个序号 * * @param number int 需要获得的序号数量 * @return String[] 序号数组 */ public static String[] getUUID(int number) { if (number < 1) { return null; } String[] ss = new String[number]; for (int i = 0; i < ss.length; i++) { ss[i] = getUUID(); } return ss; } public static void main(String[] str) { System.out.println("服务器之家测试结果："); // 得到一个序号 System.out.println(getUUID()); System.out.println("----------------------------"); // 一次得到多个序号 String[] UUID_s = getUUID(10); for (int i = 0; i < UUID_s.length; i++) { System.out.println(UUID_s[i]); } }} |
运行结果：
希望本文所述对大家java程序设计有所帮助。
原文链接：http://blog.csdn.net/lovoo/article/details/77925870
