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Java生成全局唯一ID代码演示

看了GitHub上的两个生成唯一ID的算法程序（一个出自百度，一个出自美团），打算运行着试试看，至于原理什么的文档上讲得很详细了，此处不再一一粘贴了，此处只演示代码

百度UID生成器

1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 3     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 4     <modelVersion>4.0.0</modelVersion>
 5 
 6     <groupId>com.cjs.example</groupId>
 7     <artifactId>uid-generator-demo</artifactId>
 8     <version>0.0.1-SNAPSHOT</version>
 9     <packaging>jar</packaging>
10 
11     <name>uid-generator-demo</name>
12     <description></description>
13 
14     <parent>
15         <groupId>org.springframework.boot</groupId>
16         <artifactId>spring-boot-starter-parent</artifactId>
17         <version>2.0.3.RELEASE</version>
18         <relativePath/> <!-- lookup parent from repository -->
19     </parent>
20 
21     <properties>
22         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24         <java.version>1.8</java.version>
25     </properties>
26 
27     <dependencies>
28         <dependency>
29             <groupId>org.mybatis.spring.boot</groupId>
30             <artifactId>mybatis-spring-boot-starter</artifactId>
31             <version>1.3.2</version>
32         </dependency>
33         <dependency>
34             <groupId>mysql</groupId>
35             <artifactId>mysql-connector-java</artifactId>
36             <version>5.1.46</version>
37         </dependency>
38 
39         <dependency>
40             <groupId>org.apache.commons</groupId>
41             <artifactId>commons-collections4</artifactId>
42             <version>4.2</version>
43         </dependency>
44         <dependency>
45             <groupId>org.apache.commons</groupId>
46             <artifactId>commons-lang3</artifactId>
47             <version>3.7</version>
48         </dependency>
49 
50         <dependency>
51             <groupId>org.springframework.boot</groupId>
52             <artifactId>spring-boot-starter-test</artifactId>
53             <scope>test</scope>
54         </dependency>
55     </dependencies>
56 
57     <build>
58         <plugins>
59             <plugin>
60                 <groupId>org.springframework.boot</groupId>
61                 <artifactId>spring-boot-maven-plugin</artifactId>
62             </plugin>
63         </plugins>
64     </build>
65 
66 </project>

SQL脚本

1 DROP DATABASE IF EXISTS `mytest`;
 2 CREATE DATABASE `mytest` ;
 3 use `mytest`;
 4 DROP TABLE IF EXISTS WORKER_NODE;
 5 CREATE TABLE WORKER_NODE
 6 (
 7     ID BIGINT NOT NULL AUTO_INCREMENT COMMENT 'auto increment id',
 8     HOST_NAME VARCHAR(64) NOT NULL COMMENT 'host name',
 9     PORT VARCHAR(64) NOT NULL COMMENT 'port',
10     TYPE INT NOT NULL COMMENT 'node type: ACTUAL or CONTAINER',
11     LAUNCH_DATE DATE NOT NULL COMMENT 'launch date',
12     MODIFIED TIMESTAMP NOT NULL COMMENT 'modified time',
13     CREATED TIMESTAMP NOT NULL COMMENT 'created time',
14     PRIMARY KEY(ID)
15 )COMMENT='DB WorkerID Assigner for UID Generator',ENGINE = INNODB;
复制代码

mapper文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cjs.example.baidu.uid.worker.dao.WorkerNodeDAO">
    <resultMap id="workerNodeRes"
               type="com.cjs.example.baidu.uid.worker.entity.WorkerNodeEntity">
        <id column="ID" jdbcType="BIGINT" property="id" />
        <result column="HOST_NAME" jdbcType="VARCHAR" property="hostName" />
        <result column="PORT" jdbcType="VARCHAR" property="port" />
        <result column="TYPE" jdbcType="INTEGER" property="type" />
        <result column="LAUNCH_DATE" jdbcType="DATE" property="launchDate" />
        <result column="MODIFIED" jdbcType="TIMESTAMP" property="modified" />
        <result column="CREATED" jdbcType="TIMESTAMP" property="created" />
    </resultMap>

    <insert id="addWorkerNode" useGeneratedKeys="true" keyProperty="id"
        parameterType="com.cjs.example.baidu.uid.worker.entity.WorkerNodeEntity">
        INSERT INTO WORKER_NODE
        (HOST_NAME,
        PORT,
        TYPE,
        LAUNCH_DATE,
        MODIFIED,
        CREATED)
        VALUES (
        #{hostName},
        #{port},
        #{type},
        #{launchDate},
        NOW(),
        NOW())
    </insert>

    <select id="getWorkerNodeByHostPort" resultMap="workerNodeRes">
        SELECT
        ID,
        HOST_NAME,
        PORT,
        TYPE,
        LAUNCH_DATE,
        MODIFIED,
        CREATED
        FROM
        WORKER_NODE
        WHERE
        HOST_NAME = #{host} AND PORT = #{port}
    </select>
</mapper>

application.yml配置

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mytest
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver
mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml

Spring Bean配置

package com.cjs.example;

import com.cjs.example.baidu.uid.impl.CachedUidGenerator;
import com.cjs.example.baidu.uid.impl.DefaultUidGenerator;
import com.cjs.example.baidu.uid.worker.DisposableWorkerIdAssigner;
import com.cjs.example.baidu.uid.worker.WorkerIdAssigner;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@EnableTransactionManagement
@SpringBootApplication
public class UidGeneratorDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(UidGeneratorDemoApplication.class, args);
    }

    @Autowired
    private WorkerIdAssigner workerIdAssigner;

    @Bean
    public DefaultUidGenerator defaultUidGenerator() {
        DefaultUidGenerator defaultUidGenerator = new DefaultUidGenerator();
        defaultUidGenerator.setWorkerIdAssigner(workerIdAssigner);
        defaultUidGenerator.setTimeBits(29);
        defaultUidGenerator.setWorkerBits(21);
        defaultUidGenerator.setSeqBits(13);
        defaultUidGenerator.setEpochStr("2018-07-21");
        return defaultUidGenerator;
    }

    @Bean
    public DisposableWorkerIdAssigner disposableWorkerIdAssigner() {
        return new DisposableWorkerIdAssigner();
    }

    @Bean
    public CachedUidGenerator cachedUidGenerator() {
        CachedUidGenerator cachedUidGenerator = new CachedUidGenerator();
        cachedUidGenerator.setWorkerIdAssigner(workerIdAssigner);
        cachedUidGenerator.setTimeBits(29);
        cachedUidGenerator.setWorkerBits(21);
        cachedUidGenerator.setSeqBits(13);
        cachedUidGenerator.setEpochStr("2018-07-21");
        return cachedUidGenerator;
    }

}

测试

package com.cjs.example;

import com.cjs.example.baidu.uid.impl.CachedUidGenerator;
import com.cjs.example.baidu.uid.impl.DefaultUidGenerator;
import com.cjs.example.meituan.idleaf.IdLeafService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class UidGeneratorDemoApplicationTests {

    @Autowired
    @Qualifier("defaultUidGenerator")
    private DefaultUidGenerator defaultUidGenerator;

    @Autowired
    @Qualifier("cachedUidGenerator")
    private CachedUidGenerator cachedUidGenerator;

26     27 
    @Test
    public void testSerialGenerate() {
        long uid = defaultUidGenerator.getUID();
        System.out.println(uid);
        System.out.println(defaultUidGenerator.parseUID(uid));
    }

    @Test
    public void testSerialGenerate2() {
        long uid = cachedUidGenerator.getUID();
        System.out.println(uid);
        System.out.println(cachedUidGenerator.parseUID(uid));
    }

}

美团UID生成器

Maven依赖

1 <dependency>
2     <groupId>org.apache.ignite</groupId>
3     <artifactId>ignite-zookeeper</artifactId>
4     <version>2.4.0</version>
5 </dependency>

SQL脚本

DROP TABLE IF EXISTS `id_segment`;

CREATE TABLE `id_segment` (
  `biz_tag` varchar(50) DEFAULT NULL COMMENT '业务标识',
  `max_id` bigint(20) DEFAULT NULL COMMENT '分配的id号段的最大值',
  `p_step` bigint(20) DEFAULT NULL COMMENT '步长',
  `last_update_time` datetime DEFAULT NULL,
  `current_update_time` datetime DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='号段存储表';

insert  into `id_segment`(`biz_tag`,`max_id`,`p_step`,`last_update_time`,`current_update_time`) values ('Order',60,20,'2018-07-21 15:44:02','2018-07-21 16:25:07');

Spring Bean配置

package com.cjs.example;

import com.cjs.example.meituan.idleaf.IdLeafService;
import com.cjs.example.meituan.idleaf.support.MysqlIdLeafServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@EnableTransactionManagement
@SpringBootApplication
public class UidGeneratorDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(UidGeneratorDemoApplication.class, args);
    }

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Bean(initMethod = "init")
    public IdLeafService idLeafService() {
        MysqlIdLeafServiceImpl mysqlIdLeafService = new MysqlIdLeafServiceImpl();
        mysqlIdLeafService.setJdbcTemplate(jdbcTemplate);
        mysqlIdLeafService.setAsynLoadingSegment(true);
        mysqlIdLeafService.setBizTag("Order");
        return mysqlIdLeafService;
    }
}

测试

@Autowired
private IdLeafService idLeafService;

@Test
public void testSerialGenerate3() {
    Long id = idLeafService.getId();
    System.out.println(id);
}

个人感觉无论是从文档，原理，还是代码，觉得还是百度的那个比较好用（哇咔咔O(∩_∩)O哈哈~）

还有一个Redis的方案感觉也不错

完整代码上传至 https://github.com/chengjiansheng/uid-generator-demo.git

参考

https://github.com/baidu/uid-generator

https://tech.meituan.com/MT_Leaf.html?utm_source=tuicool&utm_medium=referral

https://github.com/zhuzhong/idleaf

https://blog.csdn.net/liubenlong007/article/details/53884447

https://www.cnblogs.com/baiwa/p/5318432.html

https://blog.csdn.net/imi00/article/details/78629710

最后，关于RingBuffer（循环缓冲区，或者叫环形缓冲区）

https://blog.csdn.net/u011046042/article/details/51853535

https://www.jianshu.com/p/c3913c5cc184

https://blog.csdn.net/z69183787/article/details/52403134

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原文地址：https://www.cnblogs.com/a8457013/p/10075718.html