随机生成序列号

最新推荐文章于 2025-01-22 00:15:00 发布

原创最新推荐文章于 2025-01-22 00:15:00 发布 · 2.9k 阅读

2 ·

CC 4.0 BY-SA版权

文章标签：

#随机数 #主键ID #20位主键ID

Java 专栏收录该内容

1 篇文章

订阅专栏

该博客介绍了一个Java类`IDGenerator`，用于生成基于时间戳和随机数的20位唯一序列号。通过结合当前时间（精确到秒）和四个独立随机数生成器的输出，确保了序列号的唯一性。此外，还提供了一个生成10位序列号的方法，避免了特定数值以防止冲突。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

import java.security.SecureRandom;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class IDGenerator
{
  private static SecureRandom r1 = new SecureRandom();

  private static SecureRandom r2 = new SecureRandom();

  private static SecureRandom r3 = new SecureRandom();

  private static SecureRandom r4 = new SecureRandom();

  private static final Long L1 = Long.valueOf(1000000000L);
  private static final Long L2 = Long.valueOf(1000000L);
  private static final Long L3 = Long.valueOf(1000L);
  private static long beginMillis;

  static
  {
    try
    {
      beginMillis = new SimpleDateFormat("yyyyMMdd HH:mm:ss").parse("20100101 00:00:00").getTime();
    }
    catch (ParseException localParseException)
    {
      beginMillis = System.currentTimeMillis();
    }
  }

  public long getID20()
  {
    long timeValue = System.currentTimeMillis() / 1000L;
    int randomValue1 = Math.abs(r1.nextInt() % 1000);
    int randomValue2 = Math.abs(r2.nextInt() % 1000);
    int randomValue3 = Math.abs(r3.nextInt() % 1000);
    return timeValue * L1.longValue() + randomValue1 * L2.longValue() + randomValue2 * L3.longValue() + randomValue3;
  }

  public int getID10()
  {
    int randomNum;
    do
      randomNum = r4.nextInt(20);
    while ((randomNum == 0) || (randomNum == 2) || (randomNum == 4) || (randomNum == 6) || (randomNum == 8));

    return randomNum * 100000000 + (int)((System.currentTimeMillis() - beginMillis) / 1000L % 100000000L);
  }
}