本文是一個生成32位UUID的工具類，可直接拿去使用，如有不妥當的地方，歡迎下方留言

package com.gobestsoft.core.util;

import java.util.Random;

/**
 * 32位UUID生成器
 * 
 * @version V1.0
 * @author 
 */
public class UUIDUtil {

    /**
     * 生成不帶-的UUID
     * 
     * @return UUID
     */
    public static String getUUID() {
        // 返回用UUID
        String uuidResult = ""
 
;
        // 臨時用UUID
        String uuidTemp = "";
        // 取得UUID儲存到臨時用UUID
        uuidTemp = java.util.UUID.randomUUID().toString();

        // 替換掉所有-字元
        uuidResult = uuidTemp.replaceAll("-", "");

        // 返回UUID
        return uuidResult;
    }

    /**
     * java生成隨機數字和字母組合
     * 
     * @param
 
 length
     *            [生成隨機數的長度]
     * @return
     */
    public static String getCharAndNumr(int length) {
        String val = "";
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            // 輸出字母還是數字
            String charOrNum = random.nextInt(2) % 2 == 0 ? "char"
 
 : "num";
            // 字串
            if ("char".equalsIgnoreCase(charOrNum)) {
                // 取得大寫字母還是小寫字母
                int choice = random.nextInt(2) % 2 == 0 ? 65 : 97;
                val += (char) (choice + random.nextInt(26));
            } else if ("num".equalsIgnoreCase(charOrNum)) { // 數字
                val += String.valueOf(random.nextInt(10));
            }
        }
        return val;
    }

    /**
     * 隨機生成純數字
     * 
     * @param length
     * @return
     */
    public static String getNumber(int length) {
        char[] chars = { '1', '2', '3', '4', '5', '6', '7', '8', '9', '0' };
        Random random = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 1; i <= length; i++) {
            sb.append(chars[random.nextInt(chars.length)]);
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        System.out.println(UUIDUtil.getCharAndNumr(16));
        System.out.println(UUIDUtil.getUUID());
    }
}