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]);
}
}
}
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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