java实现随机生成UUID

public class IDGenerator {     private static long num=0;      /**   * 随机生成UUID   * @return   */  public static synchronized String getUUID(){    UUID uuid=UUID.randomUUID();    String str = uuid.toString();     String uuidStr=str.replace("-", "");    return uuidStr;  }  /**   * 根据字符串生成固定UUID   * @param name   * @return   */  public static synchronized String getUUID(String name){    UUID uuid=UUID.nameUUIDFromBytes(name.getBytes());    String str = uuid.toString();     String uuidStr=str.replace("-", "");    return uuidStr;  }  /**   * 根据日期生成长整型id   * @param args   */  public static synchronized long getLongId(){    String date=DateUtil.getDate2FormatString(new Date(), "yyyyMMddHHmmssS");    System.out.println("原始id="+date);    if(num>=99) num=0l;    ++num;    if(num<10) {      date=date+00+num;    }else{      date+=num;    }    return Long.valueOf(date);  }  }