java写一个用于生成雪花id的工具类

我们创建一个类 叫 SnowflakeIdGenerator 作为生成雪花id的工具类
然后 编写代码如下

public class SnowflakeIdGenerator {private static final long START_TIMESTAMP = 1609459200000L; // 设置起始时间戳，可以根据需要进行调整private static final long WORKER_ID_BITS = 5L; // 机器ID所占位数private static final long DATACENTER_ID_BITS = 5L; // 数据中心ID所占位数private static final long SEQUENCE_BITS = 12L; // 序列号所占位数private static final long MAX_WORKER_ID = ~(-1L << WORKER_ID_BITS); // 机器ID的最大值private static final long MAX_DATACENTER_ID = ~(-1L << DATACENTER_ID_BITS); // 数据中心ID的最大值private static final long WORKER_ID_SHIFT = SEQUENCE_BITS; // 机器ID的位移量private static final long DATACENTER_ID_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS; // 数据中心ID的位移量private static final long TIMESTAMP_LEFT_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS + DATACENTER_ID_BITS; // 时间戳的位移量private static final long SEQUENCE_MASK = ~(-1L << SEQUENCE_BITS); // 序列号的屏蔽位private final long workerId; // 机器IDprivate final long datacenterId; // 数据中心IDprivate long lastTimestamp = -1L; // 上次生成ID的时间戳private long sequence = 0L; // 序列号public SnowflakeIdGenerator(long workerId, long datacenterId) {if (workerId > MAX_WORKER_ID || workerId < 0) {throw new IllegalArgumentException("Worker ID 超出范围");}if (datacenterId > MAX_DATACENTER_ID || datacenterId < 0) {throw new IllegalArgumentException("数据中心 ID 超出范围");}this.workerId = workerId;this.datacenterId = datacenterId;}public synchronized long nextId() {long timestamp = System.currentTimeMillis();if (timestamp < lastTimestamp) {throw new RuntimeException("系统时间不正确");}if (timestamp == lastTimestamp) {sequence = (sequence + 1) & SEQUENCE_MASK;if (sequence == 0) {timestamp = tilNextMillis(lastTimestamp);}} else {sequence = 0L;}lastTimestamp = timestamp;return ((timestamp - START_TIMESTAMP) << TIMESTAMP_LEFT_SHIFT) |(datacenterId << DATACENTER_ID_SHIFT) |(workerId << WORKER_ID_SHIFT) |sequence;}private long tilNextMillis(long lastTimestamp) {long timestamp = System.currentTimeMillis();while (timestamp <= lastTimestamp) {timestamp = System.currentTimeMillis();}return timestamp;}
}

然后 只需要在其他类中调用他 获取id即可

SnowflakeIdGenerator idGenerator = new SnowflakeIdGenerator(1, 1);
long id = idGenerator.nextId();
System.out.println("新的雪花ID：" + id);

这里 我们直接new了一个SnowflakeIdGenerator类的实例
然后 通过nextId获取一个雪花id
运行结果如下

也是没有任何问题