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

Maven依赖

 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;

mapper文件

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 3 <mapper namespace="com.cjs.example.baidu.uid.worker.dao.WorkerNodeDAO">
 4     <resultMap id="workerNodeRes"
 5                type="com.cjs.example.baidu.uid.worker.entity.WorkerNodeEntity">
 6         <id column="ID" jdbcType="BIGINT" property="id" />
 7         <result column="HOST_NAME" jdbcType="VARCHAR" property="hostName" />
 8         <result column="PORT" jdbcType="VARCHAR" property="port" />
 9         <result column="TYPE" jdbcType="INTEGER" property="type" />
10         <result column="LAUNCH_DATE" jdbcType="DATE" property="launchDate" />
11         <result column="MODIFIED" jdbcType="TIMESTAMP" property="modified" />
12         <result column="CREATED" jdbcType="TIMESTAMP" property="created" />
13     </resultMap>
14 
15     <insert id="addWorkerNode" useGeneratedKeys="true" keyProperty="id"
16         parameterType="com.cjs.example.baidu.uid.worker.entity.WorkerNodeEntity">
17         INSERT INTO WORKER_NODE
18         (HOST_NAME,
19         PORT,
20         TYPE,
21         LAUNCH_DATE,
22         MODIFIED,
23         CREATED)
24         VALUES (
25         #{hostName},
26         #{port},
27         #{type},
28         #{launchDate},
29         NOW(),
30         NOW())
31     </insert>
32 
33     <select id="getWorkerNodeByHostPort" resultMap="workerNodeRes">
34         SELECT
35         ID,
36         HOST_NAME,
37         PORT,
38         TYPE,
39         LAUNCH_DATE,
40         MODIFIED,
41         CREATED
42         FROM
43         WORKER_NODE
44         WHERE
45         HOST_NAME = #{host} AND PORT = #{port}
46     </select>
47 </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

 1 package com.cjs.example;
 2 
 3 import com.cjs.example.baidu.uid.impl.CachedUidGenerator;
 4 import com.cjs.example.baidu.uid.impl.DefaultUidGenerator;
 5 import com.cjs.example.baidu.uid.worker.DisposableWorkerIdAssigner;
 6 import com.cjs.example.baidu.uid.worker.WorkerIdAssigner;
 7 import org.springframework.beans.factory.annotation.Autowired;
 8 import org.springframework.boot.SpringApplication;
 9 import org.springframework.boot.autoconfigure.SpringBootApplication;
10 import org.springframework.context.annotation.Bean;
11 import org.springframework.jdbc.core.JdbcTemplate;
12 import org.springframework.transaction.annotation.EnableTransactionManagement;
13 
14 @EnableTransactionManagement
15 @SpringBootApplication
16 public class UidGeneratorDemoApplication {
17 
18     public static void main(String[] args) {
19         SpringApplication.run(UidGeneratorDemoApplication.class, args);
20     }
21 
22     @Autowired
23     private WorkerIdAssigner workerIdAssigner;
24 
25     @Bean
26     public DefaultUidGenerator defaultUidGenerator() {
27         DefaultUidGenerator defaultUidGenerator = new DefaultUidGenerator();
28         defaultUidGenerator.setWorkerIdAssigner(workerIdAssigner);
29         defaultUidGenerator.setTimeBits(29);
30         defaultUidGenerator.setWorkerBits(21);
31         defaultUidGenerator.setSeqBits(13);
32         defaultUidGenerator.setEpochStr("2018-07-21");
33         return defaultUidGenerator;
34     }
35 
36     @Bean
37     public DisposableWorkerIdAssigner disposableWorkerIdAssigner() {
38         return new DisposableWorkerIdAssigner();
39     }
40 
41     @Bean
42     public CachedUidGenerator cachedUidGenerator() {
43         CachedUidGenerator cachedUidGenerator = new CachedUidGenerator();
44         cachedUidGenerator.setWorkerIdAssigner(workerIdAssigner);
45         cachedUidGenerator.setTimeBits(29);
46         cachedUidGenerator.setWorkerBits(21);
47         cachedUidGenerator.setSeqBits(13);
48         cachedUidGenerator.setEpochStr("2018-07-21");
49         return cachedUidGenerator;
50     }
51 
52 }

测试

 1 package com.cjs.example;
 2 
 3 import com.cjs.example.baidu.uid.impl.CachedUidGenerator;
 4 import com.cjs.example.baidu.uid.impl.DefaultUidGenerator;
 5 import com.cjs.example.meituan.idleaf.IdLeafService;
 6 import org.junit.Test;
 7 import org.junit.runner.RunWith;
 8 import org.springframework.beans.factory.annotation.Autowired;
 9 import org.springframework.beans.factory.annotation.Qualifier;
10 import org.springframework.boot.test.context.SpringBootTest;
11 import org.springframework.test.context.junit4.SpringRunner;
12 
13 @RunWith(SpringRunner.class)
14 @SpringBootTest
15 public class UidGeneratorDemoApplicationTests {
16 
17     @Autowired
18     @Qualifier("defaultUidGenerator")
19     private DefaultUidGenerator defaultUidGenerator;
20 
21     @Autowired
22     @Qualifier("cachedUidGenerator")
23     private CachedUidGenerator cachedUidGenerator;
24 
25 26     27 
28     @Test
29     public void testSerialGenerate() {
30         long uid = defaultUidGenerator.getUID();
31         System.out.println(uid);
32         System.out.println(defaultUidGenerator.parseUID(uid));
33     }
34 
35     @Test
36     public void testSerialGenerate2() {
37         long uid = cachedUidGenerator.getUID();
38         System.out.println(uid);
39         System.out.println(cachedUidGenerator.parseUID(uid));
40     }
41 
42 }

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

 1 DROP TABLE IF EXISTS `id_segment`;
 2 
 3 CREATE TABLE `id_segment` (
 4   `biz_tag` varchar(50) DEFAULT NULL COMMENT '业务标识',
 5   `max_id` bigint(20) DEFAULT NULL COMMENT '分配的id号段的最大值',
 6   `p_step` bigint(20) DEFAULT NULL COMMENT '步长',
 7   `last_update_time` datetime DEFAULT NULL,
 8   `current_update_time` datetime DEFAULT NULL
 9 ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='号段存储表';
10 
11 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

 1 package com.cjs.example;
 2 
 3 import com.cjs.example.meituan.idleaf.IdLeafService;
 4 import com.cjs.example.meituan.idleaf.support.MysqlIdLeafServiceImpl;
 5 import org.springframework.beans.factory.annotation.Autowired;
 6 import org.springframework.boot.SpringApplication;
 7 import org.springframework.boot.autoconfigure.SpringBootApplication;
 8 import org.springframework.context.annotation.Bean;
 9 import org.springframework.jdbc.core.JdbcTemplate;
10 import org.springframework.transaction.annotation.EnableTransactionManagement;
11 
12 @EnableTransactionManagement
13 @SpringBootApplication
14 public class UidGeneratorDemoApplication {
15 
16     public static void main(String[] args) {
17         SpringApplication.run(UidGeneratorDemoApplication.class, args);
18     }
19 
20     @Autowired
21     private JdbcTemplate jdbcTemplate;
22 
23     @Bean(initMethod = "init")
24     public IdLeafService idLeafService() {
25         MysqlIdLeafServiceImpl mysqlIdLeafService = new MysqlIdLeafServiceImpl();
26         mysqlIdLeafService.setJdbcTemplate(jdbcTemplate);
27         mysqlIdLeafService.setAsynLoadingSegment(true);
28         mysqlIdLeafService.setBizTag("Order");
29         return mysqlIdLeafService;
30     }
31 }

测试

1 @Autowired
2 private IdLeafService idLeafService;
3 
4 @Test
5 public void testSerialGenerate3() {
6     Long id = idLeafService.getId();
7     System.out.println(id);
8 }

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/cjsblog/p/9347304.html