fix code

hutool-core/src/main/java/org/dromara/hutool/core/data/id/Snowflake.java

@@ -15,7 +15,6 @@ package org.dromara.hutool.core.data.id;
 import org.dromara.hutool.core.date.SystemClock;
 import org.dromara.hutool.core.lang.Assert;
 import org.dromara.hutool.core.lang.tuple.Pair;
-import org.dromara.hutool.core.text.StrUtil;
 import org.dromara.hutool.core.util.RandomUtil;
 
 import java.io.Serializable;
@@ -53,11 +52,6 @@ public class Snowflake implements Serializable {
 	 * 默认的起始时间，为Thu, 04 Nov 2010 01:42:54 GMT
 	 */
 	public static long DEFAULT_TWEPOCH = 1288834974657L;
-	/**
-	 * 默认回拨时间，2S
-	 */
-	public static long DEFAULT_TIME_OFFSET = 2000L;
-
 	private static final long WORKER_ID_BITS = 5L;
 	// 最大支持机器节点数0~31，一共32个
 	@SuppressWarnings({"PointlessBitwiseExpression", "FieldCanBeLocal"})
@@ -84,10 +78,6 @@ public class Snowflake implements Serializable {
 	private final long workerId;
 	private final long dataCenterId;
 	private final boolean useSystemClock;
-	/**
-	 * 允许的时钟回拨毫秒数
-	 */
-	private final long timeOffset;
 	/**
 	 * 当在低频模式下时，序号始终为0，导致生成ID始终为偶数<br>
 	 * 此属性用于限定一个随机上限，在不同毫秒下生成序号时，给定一个随机数，避免偶数问题。<br>
@@ -146,20 +136,9 @@ public class Snowflake implements Serializable {
 	 * @param isUseSystemClock 是否使用{@link SystemClock} 获取当前时间戳
 	 * @since 5.1.3
 	 */
-	public Snowflake(final Date epochDate, final long workerId, final long dataCenterId, final boolean isUseSystemClock) {
+	public Snowflake(final Date epochDate, final long workerId, final long dataCenterId,
-		this(epochDate, workerId, dataCenterId, isUseSystemClock, DEFAULT_TIME_OFFSET);
+					 final boolean isUseSystemClock) {
-	}
+		this(epochDate, workerId, dataCenterId, isUseSystemClock, 0);
-
-	/**
-	 * @param epochDate        初始化时间起点（null表示默认起始日期）,后期修改会导致id重复,如果要修改连workerId dataCenterId，慎用
-	 * @param workerId         工作机器节点id
-	 * @param dataCenterId     数据中心id
-	 * @param isUseSystemClock 是否使用{@link SystemClock} 获取当前时间戳
-	 * @param timeOffset       允许时间回拨的毫秒数
-	 * @since 5.8.0
-	 */
-	public Snowflake(final Date epochDate, final long workerId, final long dataCenterId, final boolean isUseSystemClock, final long timeOffset) {
-		this(epochDate, workerId, dataCenterId, isUseSystemClock, timeOffset, 0);
 	}
 
 	/**
@@ -167,17 +146,15 @@ public class Snowflake implements Serializable {
 	 * @param workerId            工作机器节点id
 	 * @param dataCenterId        数据中心id
 	 * @param isUseSystemClock    是否使用{@link SystemClock} 获取当前时间戳
-	 * @param timeOffset          允许时间回拨的毫秒数
 	 * @param randomSequenceLimit 限定一个随机上限，在不同毫秒下生成序号时，给定一个随机数，避免偶数问题，0表示无随机，上限不包括值本身。
 	 * @since 5.8.0
 	 */
 	public Snowflake(final Date epochDate, final long workerId, final long dataCenterId,
-					 final boolean isUseSystemClock, final long timeOffset, final long randomSequenceLimit) {
+					 final boolean isUseSystemClock, final long randomSequenceLimit) {
 		this.twepoch = (null != epochDate) ? epochDate.getTime() : DEFAULT_TWEPOCH;
 		this.workerId = Assert.checkBetween(workerId, 0, MAX_WORKER_ID);
 		this.dataCenterId = Assert.checkBetween(dataCenterId, 0, MAX_DATA_CENTER_ID);
 		this.useSystemClock = isUseSystemClock;
-		this.timeOffset = timeOffset;
 		this.randomSequenceLimit = Assert.checkBetween(randomSequenceLimit, 0, SEQUENCE_MASK);
 	}
 
@@ -219,19 +196,16 @@ public class Snowflake implements Serializable {
 	public synchronized long nextId() {
 		long timestamp = genTime();
 		if (timestamp < this.lastTimestamp) {
-			if (this.lastTimestamp - timestamp < timeOffset) {
+			timestamp = lastTimestamp;
-				// 容忍指定的回拨，避免NTP校时造成的异常
-				timestamp = lastTimestamp;
-			} else {
-				// 如果服务器时间有问题(时钟后退) 报错。
-				throw new IllegalStateException(StrUtil.format("Clock moved backwards. Refusing to generate id for {}ms", lastTimestamp - timestamp));
-			}
 		}
 
 		if (timestamp == this.lastTimestamp) {
+			// 时间出现回拨，递增序号
 			final long sequence = (this.sequence + 1) & SEQUENCE_MASK;
 			if (sequence == 0) {
-				timestamp = tilNextMillis(lastTimestamp);
+				// 如果序号耗尽，不再等待时间追赶，而是采用“超前消费”方式，让时间递增。
+				// 这样可以避免系统暂停等待，而选择在“未来”ID新增不快时追上来。
+				timestamp += 1;
 			}
 			this.sequence = sequence;
 		} else {
@@ -295,27 +269,6 @@ public class Snowflake implements Serializable {
 	}
 
 	// ------------------------------------------------------------------------------------------------------------------------------------ Private method start
-
-	/**
-	 * 循环等待下一个时间
-	 *
-	 * @param lastTimestamp 上次记录的时间
-	 * @return 下一个时间
-	 */
-	private long tilNextMillis(final long lastTimestamp) {
-		long timestamp = genTime();
-		// 循环直到操作系统时间戳变化
-		while (timestamp == lastTimestamp) {
-			timestamp = genTime();
-		}
-		if (timestamp < lastTimestamp) {
-			// 如果发现新的时间戳比上次记录的时间戳数值小，说明操作系统时间发生了倒退，报错
-			throw new IllegalStateException(
-					StrUtil.format("Clock moved backwards. Refusing to generate id for {}ms", lastTimestamp - timestamp));
-		}
-		return timestamp;
-	}
-
 	/**
 	 * 生成时间戳
 	 *

hutool-core/src/test/java/org/dromara/hutool/core/lang/SnowflakeTest.java

@@ -94,7 +94,7 @@ public class SnowflakeTest {
 	@Disabled
 	public void snowflakeRandomSequenceTest(){
 		final Snowflake snowflake = new Snowflake(null, 0, 0,
-				false, Snowflake.DEFAULT_TIME_OFFSET, 2);
+				false, 2);
 		for (int i = 0; i < 1000; i++) {
 			final long id = snowflake.nextId();
 			Console.log(id);
@@ -107,7 +107,7 @@ public class SnowflakeTest {
 	public void uniqueOfRandomSequenceTest(){
 		// 测试并发环境下生成ID是否重复
 		final Snowflake snowflake = new Snowflake(null, 0, 0,
-				false, Snowflake.DEFAULT_TIME_OFFSET, 100);
+				false, 100);
 
 		final Set<Long> ids = new ConcurrentHashSet<>();
 		ThreadUtil.concurrencyTest(100, () -> {