From f99f645cf795a5c8ab9940b4a8f05551de4401bb Mon Sep 17 00:00:00 2001 From: ayi <2294931964@qq.com> Date: Thu, 15 Jan 2026 15:32:09 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0ID=E7=94=9F=E6=88=90=E5=99=A8?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../common/utils/SnowflakeIdGenerator.java | 180 ++++++++++++++++++ 1 file changed, 180 insertions(+) create mode 100644 xiaoyi-framework/xiaoyi-common/src/main/java/com/jy/framework/common/utils/SnowflakeIdGenerator.java diff --git a/xiaoyi-framework/xiaoyi-common/src/main/java/com/jy/framework/common/utils/SnowflakeIdGenerator.java b/xiaoyi-framework/xiaoyi-common/src/main/java/com/jy/framework/common/utils/SnowflakeIdGenerator.java new file mode 100644 index 0000000..fd2d4bf --- /dev/null +++ b/xiaoyi-framework/xiaoyi-common/src/main/java/com/jy/framework/common/utils/SnowflakeIdGenerator.java @@ -0,0 +1,180 @@ +package com.jy.framework.common.utils; + +import java.lang.management.ManagementFactory; +import java.net.InetAddress; +import java.net.NetworkInterface; + +public class SnowflakeIdGenerator { + // ====================== 配置参数 ====================== + /** 开始时间戳 (2024-01-01 00:00:00)，可自定义，减少ID长度 */ + private static final long START_TIMESTAMP = 1704067200000L; + + /** 机器ID所占的位数 (最多10位，支持1024个节点) */ + private static final long WORKER_ID_BITS = 10L; + + /** 序列号所占的位数 (最多12位，支持4096个/毫秒) */ + private static final long SEQUENCE_BITS = 12L; + + // ====================== 位移计算 ====================== + /** 机器ID左移位数 (12位) */ + private static final long WORKER_ID_SHIFT = SEQUENCE_BITS; + + /** 时间戳左移位数 (10+12=22位) */ + private static final long TIMESTAMP_LEFT_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS; + + /** 序列号的最大值 (4095) */ + private static final long SEQUENCE_MASK = ~(-1L << SEQUENCE_BITS); + + // ====================== 全局变量 ====================== + /** 机器ID (0-1023) */ + private final long workerId; + + /** 序列号 (0-4095) */ + private long sequence = 0L; + + /** 上一次生成ID的时间戳 */ + private long lastTimestamp = -1L; + + // ====================== 单例实例 ====================== + private static volatile SnowflakeIdGenerator INSTANCE; + + /** + * 私有构造器，初始化机器ID（自动计算，也可手动指定） + * + * @param workerId 机器ID (0-1023) + * @throws IllegalArgumentException 机器ID超出范围时抛出 + */ + private SnowflakeIdGenerator(long workerId) { + // 校验机器ID范围 + long maxWorkerId = ~(-1L << WORKER_ID_BITS); + if (workerId < 0 || workerId > maxWorkerId) { + throw new IllegalArgumentException(String.format("Worker ID 必须在 0 到 %d 之间", maxWorkerId)); + } + this.workerId = workerId; + } + + /** + * 获取单例实例（自动计算机器ID） + * + * @return 雪花算法生成器实例 + */ + public static SnowflakeIdGenerator getInstance() { + if (INSTANCE == null) { + synchronized (SnowflakeIdGenerator.class) { + if (INSTANCE == null) { + INSTANCE = new SnowflakeIdGenerator(calculateWorkerId()); + } + } + } + return INSTANCE; + } + + /** + * 手动指定机器ID获取实例（适合分布式部署时手动分配节点ID） + * + * @param workerId 机器ID (0-1023) + * @return 雪花算法生成器实例 + */ + public static SnowflakeIdGenerator getInstance(long workerId) { + if (INSTANCE == null) { + synchronized (SnowflakeIdGenerator.class) { + if (INSTANCE == null) { + INSTANCE = new SnowflakeIdGenerator(workerId); + } + } + } + return INSTANCE; + } + + /** + * 生成下一个ID（核心方法，线程安全） + * + * @return 有序、唯一的Long类型ID + * @throws RuntimeException 时钟回拨时抛出（避免ID重复） + */ + public synchronized long nextId() { + long currentTimestamp = System.currentTimeMillis(); + + // 检查时钟回拨（关键：避免ID重复） + if (currentTimestamp < lastTimestamp) { + throw new RuntimeException( + String.format("时钟回拨检测！拒绝生成ID，上一次时间：%d，当前时间：%d", lastTimestamp, currentTimestamp)); + } + + // 同一毫秒内，序列号递增 + if (currentTimestamp == lastTimestamp) { + sequence = (sequence + 1) & SEQUENCE_MASK; + // 同一毫秒内序列号用尽，等待下一毫秒 + if (sequence == 0) { + currentTimestamp = waitNextMillis(lastTimestamp); + } + } else { + // 不同毫秒，序列号重置为0 + sequence = 0L; + } + + // 更新最后生成ID的时间戳 + lastTimestamp = currentTimestamp; + + // 组合ID：时间戳 + 机器ID + 序列号 + return ((currentTimestamp - START_TIMESTAMP) << TIMESTAMP_LEFT_SHIFT) | (workerId << WORKER_ID_SHIFT) + | sequence; + } + + /** + * 等待下一毫秒，直到获取新的时间戳 + * + * @param lastTimestamp 上一次生成ID的时间戳 + * @return 新的时间戳 + */ + private long waitNextMillis(long lastTimestamp) { + long timestamp = System.currentTimeMillis(); + while (timestamp <= lastTimestamp) { + timestamp = System.currentTimeMillis(); + } + return timestamp; + } + + /** + * 自动计算机器ID（基于网卡+进程ID，避免手动配置） + * + * @return 0-1023之间的机器ID + */ + private static long calculateWorkerId() { + try { + // 第一步：获取网卡MAC地址的哈希值 + InetAddress address = InetAddress.getLocalHost(); + long macHash = NetworkInterface.getByInetAddress(address).getHardwareAddress()[0] & 0xFF; + + // 第二步：获取进程ID（避免同一机器多进程冲突） + String processName = ManagementFactory.getRuntimeMXBean().getName(); + long pid = Long.parseLong(processName.split("@")[0]); + + // 组合并取模，确保在0-1023之间 + return (macHash + pid) % (~(-1L << WORKER_ID_BITS)); + } catch (Exception e) { + // 异常时返回随机数（生产环境建议手动指定机器ID） + return (long)(Math.random() * (~(-1L << WORKER_ID_BITS))); + } + } + + // ====================== 测试用例 ====================== + public static void main(String[] args) { + // 测试生成10个ID，验证有序性和唯一性 + SnowflakeIdGenerator generator = SnowflakeIdGenerator.getInstance(); + for (int i = 0; i < 10; i++) { + long id = generator.nextId(); + System.out.println("生成的ID：" + id); + } + + // 多线程测试（验证线程安全） + Runnable task = () -> { + for (int i = 0; i < 5; i++) { + System.out.println(Thread.currentThread().getName() + " -> " + generator.nextId()); + } + }; + new Thread(task, "线程1").start(); + new Thread(task, "线程2").start(); + } + +}