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);
  }
  
}