还可以直接
这是工具类自带的，推荐
IdUtil.getSnowflake().nextId()
public class SnowflakeIdGenerator {
private static final long START_TIMESTAMP = 1630000000000L;
private static final long WORKER_ID_BITS = 5L;
private static final long MAX_WORKER_ID = ~(-1L << WORKER_ID_BITS);
private static final long SEQUENCE_BITS = 12L;
private static final long WORKER_ID_SHIFT = SEQUENCE_BITS;
private static final long TIMESTAMP_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS;
private static final long SEQUENCE_MASK = ~(-1L << SEQUENCE_BITS);
private final long workerId;
private long sequence = 0L;
private long lastTimestamp = -1L;
public SnowflakeIdGenerator(long workerId) {
if (workerId < 0 || workerId > MAX_WORKER_ID) {
throw new IllegalArgumentException("Worker ID must be between 0 and " + MAX_WORKER_ID);
}
this.workerId = workerId;
}
public synchronized long nextId() {
long timestamp = System.currentTimeMillis();
if (timestamp < lastTimestamp) {
throw new RuntimeException("Clock moved backwards. Refusing to generate ID for " + (lastTimestamp - timestamp) + " milliseconds.");
}
if (timestamp == lastTimestamp) {
sequence = (sequence + 1) & SEQUENCE_MASK;
if (sequence == 0) {
timestamp = tilNextMillis(lastTimestamp);
}
} else {
sequence = 0L;
}
lastTimestamp = timestamp;
return ((timestamp - START_TIMESTAMP) << TIMESTAMP_SHIFT) | (workerId << WORKER_ID_SHIFT) | sequence;
}
private long tilNextMillis(long lastTimestamp) {
long timestamp = System.currentTimeMillis();
while (timestamp <= lastTimestamp) {
timestamp = System.currentTimeMillis();
}
return timestamp;
}
}