自己写雪花算法IdWorker
package com.aiyusheng.shopping.util; import java.lang.management.ManagementFactory; import java.net.InetAddress; import java.net.NetworkInterface; import java.text.SimpleDateFormat; import java.util.Date; /** * <p>名称:IdWorker.java</p> * <p>描述:分布式自增长ID</p> * <pre> * Twitter的 Snowflake JAVA实现方案 * </pre> * 核心代码为其IdWorker这个类实现,其原理结构如下,我分别用一个0表示一位,用—分割开部分的作用: * 1||0---0000000000 0000000000 0000000000 0000000000 0 --- 00000 ---00000 ---000000000000 * 在上面的字符串中,第一位为未使用(实际上也可作为long的符号位),接下来的41位为毫秒级时间, * 然后5位datacenter标识位,5位机器ID(并不算标识符,实际是为线程标识), * 然后12位该毫秒内的当前毫秒内的计数,加起来刚好64位,为一个Long型。 * 这样的好处是,整体上按照时间自增排序,并且整个分布式系统内不会产生ID碰撞(由datacenter和机器ID作区分), * 并且效率较高,经测试,snowflake每秒能够产生26万ID左右,完全满足需要。 * <p> * 64位ID (42(毫秒)+5(机器ID)+5(业务编码)+12(重复累加)) * * @author Polim */ public class IdWorker { // 时间起始标记点,作为基准,一般取系统的最近时间(一旦确定不能变动) private final static long TWEPOCH= 1288834974657L; // 机器标识位数 private final static long WORKDER_ID_BITS = 5L; // 数据中心标识位数 private final static long DATACENTER_ID_BITS = 5L; // 机器ID最大值 private final static long MAX_WORKDER_ID= -1L ^ (-1L << WORKDER_ID_BITS); // 数据中心ID最大值 private final static long MAX_DATACENTER_ID= -1L ^ (-1L << DATACENTER_ID_BITS); // 毫秒内自增位 private final static long SEQUENCE_BITS= 12L; // 机器ID偏左移12位 private final static long WORKDER_ID_SHIFT= SEQUENCE_BITS; // 数据中心ID左移17位 private final static long DATACENTER_ID_SHIFT= SEQUENCE_BITS + WORKDER_ID_BITS; // 时间毫秒左移22位 private final static long TIMESTAMP_LEFT_SHIFT = SEQUENCE_BITS + WORKDER_ID_BITS + SEQUENCE_BITS; private final static long SEQUENCE_MASK= -1L ^ (-1L << SEQUENCE_BITS); /* 上次生产id时间戳 */ private static long lastTimestamp = -1L; // 0,并发控制 private long sequence = 0L; private final long workerId; // 数据标识id部分 private final long datacenterId; public IdWorker(){ this.datacenterId = getDatacenterId(MAX_DATACENTER_ID); this.workerId = getMaxWorkerId(datacenterId, MAX_WORKDER_ID); } /** * @param workerId * 工作机器ID * @param datacenterId * 序列号 */ public IdWorker(long workerId, long datacenterId) { if (workerId > MAX_WORKDER_ID || workerId < 0) { throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", MAX_WORKDER_ID)); } if (datacenterId > MAX_WORKDER_ID || datacenterId < 0) { throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", MAX_DATACENTER_ID)); } this.workerId = workerId; this.datacenterId = datacenterId; } /** * 获取下一个ID * * @return */ 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) { // 当前毫秒内,则+1 sequence = (sequence + 1) & SEQUENCE_MASK; if (sequence == 0) { // 当前毫秒内计数满了,则等待下一秒 timestamp = tilNextMillis(lastTimestamp); } } else { sequence = 0L; } lastTimestamp = timestamp; // ID偏移组合生成最终的ID,并返回ID long nextId = ((timestamp - TWEPOCH) << TIMESTAMP_LEFT_SHIFT) | (datacenterId << DATACENTER_ID_SHIFT) | (workerId << WORKDER_ID_SHIFT) | sequence; return nextId; } /** * 功能描述: 自动补全生成32位 * @Param: * @Return: java.lang.String * @Author: chenzhian * @Date: 2020/12/2 17:24 * @Description: */ public synchronized String next32Id(){ String Id= nextId()+""; String nowtime = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()); Integer surplusLength=32-Id.length()-nowtime.length(); if(surplusLength>0){ //自动补缺数字 String strsurplus = String.format("%0"+surplusLength+"d", 0); return nowtime+strsurplus+Id; }else if(surplusLength==0){ return nowtime+Id; }else{ return nowtime.substring(0,(nowtime.length()+surplusLength))+Id; } } /** * 阻塞到下一个毫秒,直到获得新的时间戳 * @param lastTimestamp 上次生成ID的时间截 * @return 当前时间戳 */ private long tilNextMillis(final long lastTimestamp) { long timestamp = this.timeGen(); while (timestamp <= lastTimestamp) { timestamp = this.timeGen(); } return timestamp; } /** * 返回以毫秒为单位的当前时间 * @return 当前时间(毫秒) */ private long timeGen() { return System.currentTimeMillis(); } /** * <p> * 获取 maxWorkerId * </p> */ protected static long getMaxWorkerId(long datacenterId, long maxWorkerId) { StringBuffer mpid = new StringBuffer(); mpid.append(datacenterId); String name = ManagementFactory.getRuntimeMXBean().getName(); if (!name.isEmpty()) { /* * GET jvmPid */ mpid.append(name.split("@")[0]); } /* * MAC + PID 的 hashcode 获取16个低位 */ return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1); } /** * <p> * 数据标识id部分 * </p> */ protected static long getDatacenterId(long maxDatacenterId) { long id = 0L; try { InetAddress ip = InetAddress.getLocalHost(); NetworkInterface network = NetworkInterface.getByInetAddress(ip); if (network == null) { id = 1L; } else { byte[] mac = network.getHardwareAddress(); id = ((0x000000FF & (long) mac[mac.length - 1]) | (0x0000FF00 & (((long) mac[mac.length - 2]) << 8))) >> 6; id = id % (maxDatacenterId + 1); } } catch (Exception e) { System.out.println(" getDatacenterId: " + e.getMessage()); } return id; } }
package com.aiyusheng.shopping.config; import org.springframework.boot.context.properties.ConfigurationProperties; @ConfigurationProperties(prefix = "ly.worker") public class IdWorkerProperties { private long workerId;// 当前机器id private long datacenterId;// 序列号 public long getWorkerId() { return workerId; } public void setWorkerId(long workerId) { this.workerId = workerId; } public long getDatacenterId() { return datacenterId; } public void setDatacenterId(long datacenterId) { this.datacenterId = datacenterId; } }
package com.aiyusheng.shopping.config; import com.aiyusheng.shopping.util.IdWorker; import org.springframework.boot.context.properties.EnableConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration @EnableConfigurationProperties(IdWorkerProperties.class) public class IdWorkerConfig { @Bean public IdWorker idWorker(IdWorkerProperties prop) { return new IdWorker(prop.getWorkerId(), prop.getDatacenterId()); } }
配置文件application.properties
ly.worker.workerId=1
ly.worker.datacenterId=1