From 13b31b2ca2a5f8600002a042b536c9d5529842e3 Mon Sep 17 00:00:00 2001
From: Junjie <fallin.jie@qq.com>
Date: 星期一, 09 三月 2026 19:21:18 +0800
Subject: [PATCH] #

---
 src/main/java/com/core/common/SnowflakeIdWorker.java |   78 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 78 insertions(+), 0 deletions(-)

diff --git a/src/main/java/com/core/common/SnowflakeIdWorker.java b/src/main/java/com/core/common/SnowflakeIdWorker.java
new file mode 100644
index 0000000..7dd3d7b
--- /dev/null
+++ b/src/main/java/com/core/common/SnowflakeIdWorker.java
@@ -0,0 +1,78 @@
+package com.core.common;
+
+public class SnowflakeIdWorker {
+
+    private final long twepoch = 1420041600000L;
+    private final long sequenceBits = 12L;
+    private final long workerIdBits = 5L;
+    private final long datacenterIdBits = 5L;
+    private final long workerIdLeftShift = 12L;
+    private final long datacenterIdLeftShift = 17L;
+    private final long timestampLeftShift = 22L;
+    private final long maxWorkerId = 31L;
+    private final long maxDatacenterId = 31L;
+    private final long sequenceMask = 4095L;
+
+    private long workerId;
+    private long datacenterId;
+    private long sequence = 0L;
+    private long lastTimestamp = -1L;
+
+    public SnowflakeIdWorker(long workerId, long datacenterId) {
+        if (workerId > maxWorkerId || workerId < 0) {
+            throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
+        }
+        if (datacenterId > maxDatacenterId || datacenterId < 0) {
+            throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
+        }
+        this.workerId = workerId;
+        this.datacenterId = datacenterId;
+    }
+
+    public SnowflakeIdWorker() {
+        this(0L, 0L);
+    }
+
+    public synchronized long nextId() {
+        long timestamp = timeGen();
+        if (timestamp < lastTimestamp) {
+            throw new RuntimeException(String.format(
+                    "Clock moved backwards.  Refusing to generate id for %d milliseconds",
+                    lastTimestamp - timestamp));
+        }
+        if (lastTimestamp == timestamp) {
+            sequence = (sequence + 1) & sequenceMask;
+            if (sequence == 0) {
+                timestamp = tilNextMillis(lastTimestamp);
+            }
+        } else {
+            sequence = 0L;
+        }
+        lastTimestamp = timestamp;
+        return ((timestamp - twepoch) << timestampLeftShift)
+                | (datacenterId << datacenterIdLeftShift)
+                | (workerId << workerIdLeftShift)
+                | sequence;
+    }
+
+    protected long tilNextMillis(long lastTimestamp) {
+        long timestamp = timeGen();
+        while (timestamp <= lastTimestamp) {
+            timestamp = timeGen();
+        }
+        return timestamp;
+    }
+
+    protected long timeGen() {
+        return System.currentTimeMillis();
+    }
+
+    public static void main(String[] args) {
+        SnowflakeIdWorker idWorker = new SnowflakeIdWorker(0L, 0L);
+        for (int i = 0; i < 1000; i++) {
+            long id = idWorker.nextId();
+            System.out.println(Long.toBinaryString(id));
+            System.out.println(id);
+        }
+    }
+}

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