介绍

源码地址

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

UidGenerator以组件形式工作在应用项目中，支持自定义workerId位数和初始化策略，从而适用于docker等虚拟化环境下实例自动重启、漂移等场景。

在实现上，UidGenerator通过借用未来时间来解决sequence天然存在的并发限制；采用RingBuffer来缓存已生成的UID，并行化UID的生产和消费，同时对CacheLine补齐，避免了由RingBuffer带来的硬件级「伪共享」问题，最终单机QPS可达600万。

打包源码

导包

注意事项：请在需要集成UidGenerator的项目进行导包操作，输入如下命令进行如下操作进行导包，注意修改jar包位置

mvn install:install-file -Dfile=/opt/uid-generator-1.0.0-SNAPSHOT.jar -DgroupId=com.generator -DartifactId=uid-generator -Dversion=1.0.0-SNAPSHOT -Dpackaging=jar

引入依赖

注意事项：由于UidGenerator默认集成了MyBatis和MyBatis Spring相关依赖，本项目使用的是MyBatis Plus，因此要把MyBatis和MyBatis Spring的依赖排除。

<dependency>
    <groupId>com.generator</groupId>
    <artifactId>uid-generator</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <exclusions>
        <exclusion>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>commons-lang</groupId>
    <artifactId>commons-lang</artifactId>
    <version>2.6</version>
</dependency>

创建数据表

DROP TABLE IF EXISTS `worker_node`;
CREATE TABLE `worker_node` (
  `work_node_id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',
  `host_name` varchar(64) NOT NULL COMMENT '主机名称',
  `port` varchar(64) NOT NULL COMMENT '端口',
  `type` int NOT NULL COMMENT '类型(ACTUAL or CONTAINER)',
  `launch_date` date NOT NULL COMMENT '年月日',
  `create_time` datetime(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) COMMENT '创建时间',
  `update_time` datetime(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3) COMMENT '修改时间',
  PRIMARY KEY (`work_node_id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

创建实体类

@Data
@TableName("worker_node")
public class WorkNode {

    @TableId(value = "work_node_id", type = IdType.AUTO)
    private Long workNodeId;

    /**
     * 主机名称
     */
    private String hostName;

    /**
     * 端口
     */
    private String port;

    /**
     * 类型(ACTUAL or CONTAINER)
     */
    private Integer type;

    /**
     * 年月日
     */
    private Date launchDate;

    /**
     * 创建时间
     */
    private Date createTime;

    /**
     * 修改时间
     */
    @TableField(update = "now()")
    private Date updateTime;
}

创建持久层

@Repository
public interface WorkerNodeMapper extends BaseMapper<WorkNode> {
}

创建接口及实现类

public interface WorkNodeService extends IService<WorkNodeDO> {
    WorkNodeDO getWorkerNodeByHostPort(String host, String port);

    void insertWorkerNode(WorkNodeDO workNode);
}

@Service
public class WorkNodeServiceImpl extends ServiceImpl<WorkerNodeMapper, WorkNodeDO> implements WorkNodeService {

    @Override
    public WorkNodeDO getWorkerNodeByHostPort(String host, String port) {
        return null;
    }

    @Override
    public void insertWorkerNode(WorkNodeDO workNode) {

    }
}

创建UidGenerator配置类

public class DisposableWorkerIdAssigner implements WorkerIdAssigner {

    @Autowired
    private WorkNodeService workNodeService;

    /**
     * Assign worker id base on database.<p>
     * If there is host name & port in the environment, we considered that the node runs in Docker container<br>
     * Otherwise, the node runs on an actual machine.
     *
     * @return assigned worker id
     */
    @Transactional(rollbackFor = Exception.class)
    @Override
    public long assignWorkerId() {
        WorkNodeDO workNode = buildWorkerNode();
        workNodeService.insertWorkerNode(workNode);
        return workNode.getWorkNodeId();
    }

    /**
     * Build worker node entity by IP and PORT
     */
    private WorkNodeDO buildWorkerNode() {
        WorkNodeDO workNode = new WorkNodeDO();
        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() + "-" + new Random().nextInt(100000));
            workNode.setLaunchDate(new Date());
        }
        return workNode;
    }
}

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

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

测试

@RestController
@RequestMapping("/v1/test")
public class TestController {
    @Autowired
    private UidGenerator uidGenerator;

    @GetMapping("/uid")
    public Long index() {
        return uidGenerator.getUID();
    }
}