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
