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:
sign(1bit) | 固定1bit符号标识,即生成的UID为正数。 |
---|---|
delta seconds (28 bits) | 当前时间,相对于时间基点"2016-05-20"的增量值,单位:秒,最多可支持约8.7年 |
worker id (22 bits) | 机器id,最多可支持约420w次机器启动。内置实现为在启动时由数据库分配,默认分配策略为用后即弃,后续可提供复用策略。 |
sequence (13 bits) | 每秒下的并发序列,13 bits可支持每秒8192个并发。 |
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
java
/**
* @注释
*/
public interface IWorkerNodeService {
public long genUid();
}
- serviceimpl
java
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);
});
}
}