一、简介

uid-generator是由百度技术部开发,GitHub地址

UidGenerator是Java实现的, 基于Snowflake算法的唯一ID生成器

Snowflake算法

Snowflake算法描述：指定机器 & 同一时刻 & 某一并发序列，是唯一的。据此可生成一个64 bits的唯一ID（long）。默认采用上图字节分配方式：

二、使用Spring boot项目集成uid-generator

2.1 将项目下载之后生成文件

下载完成后使用IDEA打开

复制生成的文件夹到maven仓库

我的maven仓库安装到了d盘

之后就可以使用标签引入了

2.2项目中引入uid-generator依赖，并排除其中的mybatis依赖

如果项目是SpringBoot+Mybatisplus，UidGenerator是Spring+Mybatis，直接引入uid-generator之后，本地项目启动就会出现创建SqlSessionFactory报错，所以，直接将uid-generator中的mybatis相关依赖排除。避免出现不必要的启动问题

<dependency>
    <groupId>com.baidu.fsg</groupId>
    <artifactId>uid-generator</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <exclusions>
        <exclusion>
            <groupId>org.mybatis</groupId>
            <artifactId>*</artifactId>
        </exclusion>
    </exclusions>
</dependency>

2.3 创建数据库表

DROP TABLE IF EXISTS WORKER_NODE;
CREATE TABLE WORKER_NODE
(
ID BIGINT NOT NULL AUTO_INCREMENT COMMENT 'auto increment id',
HOST_NAME VARCHAR(64) NOT NULL COMMENT 'host name',
PORT VARCHAR(64) NOT NULL COMMENT 'port',
TYPE INT NOT NULL COMMENT 'node type: ACTUAL or CONTAINER',
LAUNCH_DATE DATE NOT NULL COMMENT 'launch date',
MODIFIED TIMESTAMP NOT NULL COMMENT 'modified time',
CREATED TIMESTAMP NOT NULL COMMENT 'created time',
PRIMARY KEY(ID)
)
 COMMENT='DB WorkerID Assigner for UID Generator',ENGINE = INNODB;

2.4 生成实体类与mapper

2.4.1实体类

import java.util.Date;

public class WorkerNode {

    private Long id;

    private String hostName;

    private String port;

    private Integer type;

    private Date LaunchDate;

    private Date modified;

    private Date created;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getHostName() {
        return hostName;
    }

    public void setHostName(String hostName) {
        this.hostName = hostName;
    }

    public String getPort() {
        return port;
    }

    public void setPort(String port) {
        this.port = port;
    }

    public Integer getType() {
        return type;
    }

    public void setType(Integer type) {
        this.type = type;
    }

    public Date getLaunchDate() {
        return LaunchDate;
    }

    public void setLaunchDate(Date launchDate) {
        LaunchDate = launchDate;
    }

    public Date getModified() {
        return modified;
    }

    public void setModified(Date modified) {
        this.modified = modified;
    }

    public Date getCreated() {
        return created;
    }

    public void setCreated(Date created) {
        this.created = created;
    }

    @Override
    public String toString() {
        return "WorkerNode{" +
                "id=" + id +
                ", hostName='" + hostName + '\'' +
                ", port='" + port + '\'' +
                ", type=" + type +
                ", LaunchDate=" + LaunchDate +
                ", modified=" + modified +
                ", created=" + created +
                '}';
    }
}

2.4.2 mapper与mapper.xml

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface WorkerNodeMapper {

    int addWorkerNode(WorkerNode workerNodeEntity);


    WorkerNode getWorkerNodeByHostPort(@Param("host") String host, @Param("port") String port);

}

<?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.lq.mapper.WorkerNodeMapper">
    <resultMap id="BaseResultMap"
               type="com.lq.entity.pojo.WorkerNode">
        <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.lq.entity.pojo.WorkerNode">
        INSERT INTO WORKER_NODE
        (HOST_NAME,
         PORT,
         TYPE,
         LAUNCH_DATE,
         MODIFIED,
         CREATED)
        VALUES (
                   #{hostName},
                   #{port},
                   #{type},
                   #{launchDate},
                   NOW(),
                   NOW())
    </insert>

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

注:

修改对应位置为自己实体类与mapper所在位置

2.5 service与impl

• service

/**
 * @注释
 */
public interface IWorkerNodeService {

    public long genUid();
}

• serviceimpl

import com.baidu.fsg.uid.UidGenerator;
import com.lq.service.IWorkerNodeService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

/**
 */
@Service
public class WorkerNodeServiceImpl implements IWorkerNodeService {
    @Resource
    private UidGenerator uidGenerator;

    @Override
    public long genUid() {
        return uidGenerator.getUID();
    }
}

2.6 添加配置类

2.6.1 DisposableWorkerIdAssigner

import com.baidu.fsg.uid.utils.DockerUtils;
import com.baidu.fsg.uid.utils.NetUtils;
import com.baidu.fsg.uid.worker.WorkerIdAssigner;
import com.baidu.fsg.uid.worker.WorkerNodeType;
import org.apache.commons.lang.math.RandomUtils;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.util.Date;

/**
 */
public class DisposableWorkerIdAssigner implements WorkerIdAssigner {

    @Resource
    private WorkerNodeMapper workerNodeMapper;

    @Override
    @Transactional
    public long assignWorkerId() {
        WorkerNode workerNode = buildWorkerNode();

        workerNodeMapper.addWorkerNode(workerNode);

        return workerNode.getId();
    }

    private WorkerNode buildWorkerNode() {
        WorkerNode workNode = new WorkerNode();
        if (DockerUtils.isDocker()) {
            workNode.setType(WorkerNodeType.CONTAINER.value());
            workNode.setHostName(DockerUtils.getDockerHost());
            workNode.setPort(DockerUtils.getDockerPort());
            workNode.setLaunchDate(new Date());
        } else {
            workNode.setType(WorkerNodeType.ACTUAL.value());
            workNode.setHostName(NetUtils.getLocalAddress());
            workNode.setPort(System.currentTimeMillis() + "-" + RandomUtils.nextInt(100000));
            workNode.setLaunchDate(new Date());
        }

        return workNode;
    }
}

2.6.2 WorkerNodeConfig

import com.baidu.fsg.uid.UidGenerator;
import com.baidu.fsg.uid.impl.CachedUidGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/** 
 */
@Configuration
public class WorkerNodeConfig {

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

    @Bean("cachedUidGenerator")
    public UidGenerator uidGenerator(DisposableWorkerIdAssigner disposableWorkerIdAssigner){
        CachedUidGenerator cachedUidGenerator = new CachedUidGenerator();
        cachedUidGenerator.setWorkerIdAssigner(disposableWorkerIdAssigner);
        return cachedUidGenerator;
    }
}

2.7 测试

import com.lq.service.IWorkerNodeService;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 */
@SpringBootTest
public class UidGenerateTest {

    @Resource
    private IWorkerNodeService workerNodeService;

    @Test
    public void getUid() {
        List<Long> list = new ArrayList<>();
        for (int i = 0; i < 50; i++) {
            long uid = workerNodeService.genUid();
            list.add(uid);
        }
        AtomicInteger num = new AtomicInteger();
        list.forEach(l -> {
            System.out.println("第" + num.getAndIncrement() + "个id为 = " + l);
        });
    }
}