07、Sharding-JDBC 实战;SpringBoot整合Sharding-JDBC通过混合分片策略(Complex)实现分表操作

1、SpringBoot基础配置

框架搭建:SpringBoot + HikariCP/Druid + Mybatis + Mysql+sharding-jdbc

1、POM依赖:

<dependency>
      <groupId>org.apache.shardingsphere</groupId>
      <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
      <version>4.1.1</version>
</dependency>

2、配置允许数据源覆盖
properties文件加入以下配置

# 允许数据源覆盖
spring.main.allow-bean-definition-overriding=true

3、数据源配置
数据源类型通常选择DruidDataSource或者HikariDataSource两者在配置上有所不同。

  • DruidDataSource
  <!-- 不能使用druid-spring-boot-starter,会导致:Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required -->
   <dependency>
     <groupId>com.alibaba</groupId>
     <artifactId>druid</artifactId>
     <version>version</version>
   </dependency>

 com.alibaba.druid.pool.DruidDataSource
 DruidDataSource需要引入druid的Jar包,使用:url
  spring.shardingsphere.datasource.m1.type=com.alibaba.druid.pool.DruidDataSource
  spring.shardingsphere.datasource.m1.url=

  • HikariDataSource
 com.zaxxer.hikari.HikariDataSource
 HikariDataSource要使用:jdbc-url
  spring.shardingsphere.datasource.m1.type=com.zaxxer.hikari.HikariDataSource
  spring.shardingsphere.datasource.m1.jdbc-url=

2、创建表

将用户(user)表,进行水平分表,分为:user_1,user_2 .... user_6

//创建数据表
CREATE TABLE user_1/user_2/..../user_6 (
    id BIGINT(20) NOT NULL COMMENT 'Id',
    name VARCHAR(20) NOT NULL COMMENT '名称',
    phone VARCHAR(20) NOT NULL COMMENT '电话',
    email VARCHAR(20) NOT NULL COMMENT '邮箱',
    PRIMARY KEY (id)
) 

3、完整properties配置

server.port=9090
server.servlet.context-path=/demo
spring.application.name=sharding-jdbc-simple-demo
# 允许数据源覆盖
spring.main.allow-bean-definition-overriding=true
# MyBatis配置
# 搜索指定包别名
mybatis.typeAliasesPackage=com.lhz.sharding.model.entity
# 配置mapper的扫描,找到所有的mapper.xml映射文件
mybatis.mapperLocations=classpath*:mybatis/**/*.xml
#数据库类型
mybatis.configuration.database-id=mysql
#自动驼峰转换
mybatis.configuration.map-underscore-to-camel-case=true
#pagehelper  分页插件
pagehelper.helper-dialect=mysql
pagehelper.reasonable=false
pagehelper.support-methods-arguments=true
pagehelper.params=count=countSql

#sharding-jdbc 水平分表规则配置,使用complex模式
# 数据源名称,多数据源逗号隔开
spring.shardingsphere.datasource.names=m1
spring.shardingsphere.datasource.m1.type=com.zaxxer.hikari.HikariDataSource
spring.shardingsphere.datasource.m1.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.m1.jdbc-url=jdbc:mysql://127.0.0.1:3307/shardingjdbc?useUnicode=true&useSSL=false&zeroDateTimeBehavior=convertToNull&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai
spring.shardingsphere.datasource.m1.username=root
spring.shardingsphere.datasource.m1.password=lhzlx
# 水平分表:user_1/2/3..,多个表进行分表时,依次在tables标签后写逻辑
# user_1/2/3... 为数据库中的事实表
# user为xml编码中操作的逻辑表,sharding-jdbc会自动根据策略操作事实表
# 配置节点分布情况,表示有user_1到user_6共6张表
spring.shardingsphere.sharding.tables.user.actual-data-nodes=m1.user_$->{1..6}
# 指定user表的主键生成策略为SNOWFLAKE
spring.shardingsphere.sharding.tables.user.key-generator.column=id
spring.shardingsphere.sharding.tables.user.key-generator.type=SNOWFLAKE

# 指定user表的分片策略,分片策略包括分片键和分片算法
# 配置表的分片策略
spring.shardingsphere.sharding.tables.user.table-strategy.complex.sharding-columns=id
# 复合分片算法
spring.shardingsphere.sharding.tables.user.table-strategy.complex.algorithm-class-name=\
  com.lhz.sharding.algorithm.MyComplexKeysShardingAlgorithm
# 打开sql输出日志
spring.shardingsphere.props.sql.show=true

4、分片算法

混合分片策略,支持多个分片健操作,并且集成了精确匹配与范围匹配查询,具体处理逻辑如下代码

MyComplexKeysShardingAlgorithm:

import com.google.common.collect.Range;
import org.apache.shardingsphere.api.sharding.complex.ComplexKeysShardingAlgorithm;
import org.apache.shardingsphere.api.sharding.complex.ComplexKeysShardingValue;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

/**
 * @Description:
 **/
public class MyComplexKeysShardingAlgorithm implements ComplexKeysShardingAlgorithm<Long> {
   
     
    /**
     * @param tbNames                  数据库中所有的事实表
     * @param complexKeysShardingValue 分片相关信息
     * @return
     */
    @Override
    public Collection<String> doSharding(Collection<String> tbNames, ComplexKeysShardingValue<Long> complexKeysShardingValue) {
   
     

        String logicTableName = complexKeysShardingValue.getLogicTableName();

        // 获取范围查询匹配的值
        Range<Long> range = this.getRangeValue(complexKeysShardingValue, "id");
        if (range != null) {
   
     
            // between and 的起始值,需要处理只有最大值或者只有最小值的情况
            boolean hasLowerBound = range.hasLowerBound();
            boolean hasUpperBound = range.hasUpperBound();

            // 只有最小值,比如:id > x
            if (hasLowerBound && !hasUpperBound) {
   
     
                // 直接返回所有表名称
                return tbNames;
            }

            // 只有最大值,比如:id < x
            if (!hasLowerBound && hasUpperBound) {
   
     
                long upper = range.upperEndpoint();
                if (upper < tbNames.size()) {
   
     
                    // 如果最大值小于表的总数,则返回需要的表名
                    return matchMinAndMax(1, upper, logicTableName, tbNames);
                } else {
   
     
                    // 如果最大值大于表的总数,则返回所有
                    return tbNames;
                }
            }

            // 区间值情况
            long lower = range.lowerEndpoint();
            long upper = range.upperEndpoint();

            // 拼接事实表名称
            return matchMinAndMax(lower, upper, logicTableName, tbNames);
        }

        // 得到每个分片健对应的值,如果有多个则取多个实现相应逻辑即可
        Collection<Long> ids = this.getShardingValue(complexKeysShardingValue, "id");

        // 先按原有方式处理,注意 IN的情况,是不是返回多个对象
        List<String> tableNameList = new ArrayList<>();
        for (Long id : ids) {
   
     
            long tableNum = id % tbNames.size();
            // 事实表后缀
            String suffix = String.valueOf(tableNum == 0 ? tableNum + 6 : tableNum);
            String tableName = logicTableName + "_" + suffix;
            if (tbNames.contains(tableName)) {
   
     
                // 添加满足要求的表名称
                tableNameList.add(tableName);
            }

            // 如果满足要求的表已经覆盖了所有表,此处处理是为了方式查询区间过大,而分表不多,导致的过度遍历
            if (tableNameList.size() == tbNames.size()) {
   
     
                return tableNameList;
            }
        }
        return tableNameList;
    }

    private Collection<Long> getShardingValue(ComplexKeysShardingValue<Long> shardingValues, final String column) {
   
     
        Collection<Long> valueSet = new ArrayList<>();
        // 匹配分片字段
        Map<String, Collection<Long>> columnNameAndShardingValuesMap = shardingValues.getColumnNameAndShardingValuesMap();
        if (columnNameAndShardingValuesMap.containsKey(column)) {
   
     
            valueSet.addAll(columnNameAndShardingValuesMap.get(column));
        }
        return valueSet;
    }

    private Range<Long> getRangeValue(ComplexKeysShardingValue<Long> shardingValues, final String column) {
   
     
        // 匹配分片字段
        Map<String, Range<Long>> columnNameAndRangeValuesMap = shardingValues.getColumnNameAndRangeValuesMap();
        if (columnNameAndRangeValuesMap.containsKey(column)) {
   
     
            return columnNameAndRangeValuesMap.get(column);
        }
        return null;
    }

    private List<String> matchMinAndMax(long lower, long upper, String logicTableName, Collection<String> tbNames) {
   
     
        List<String> tableNameList = new ArrayList<>();
        for (long index = lower; index <= upper; index++) {
   
     
            long tableNum = index % tbNames.size();
            // 事实表后缀
            String suffix = String.valueOf(tableNum == 0 ? tableNum + 6 : tableNum);
            String tableName = logicTableName + "_" + suffix;
            if (tbNames.contains(tableName)) {
   
     
                // 添加满足要求的表名称
                tableNameList.add(tableName);
            }

            // 如果满足要求的表已经覆盖了所有表,此处处理是为了方式查询区间过大,而分表不多,导致的过度遍历
            if (tableNameList.size() == tbNames.size()) {
   
     
                return tableNameList;
            }
        }
        return tableNameList;
    }
}

范围查询示例:

 
精确查询示例:

 

5、实体类

User :

@Data
public class User implements Serializable {
   
     
    private Long id;

    private String name;

    private String phone;

    private String email;
}

6、Mapper类

ComplexMapper :

@Mapper
public interface ComplexMapper {
   
     
    /**
     * 根据ID查询
     *
     * @param id
     * @return
     */
    User selectById(@Param("id") Long id);

    List<User> selectByIn(@Param("ids") List<Long> ids);

    /**
     * 根据ID删除
     *
     * @param id
     * @return
     */
    int deleteById(@Param("id") Long id);

    /**
     * 根据ID更新
     *
     * @param id
     * @return
     */
    int updateById(@Param("id") Long id);
    /**
     * 新增数据
     *
     * @param min
     * @param max
     * @return
     */
    List<User> listByRange(@Param("min") Long min, @Param("max") Long max);

    int insert(User user);

    int insertBatch(List<User> list);
}

StandardMapper.xml:

<?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.lhz.sharding.mapper.ComplexMapper">

    <select id="selectById" parameterType="java.lang.Long"
            resultType="com.lhz.sharding.model.entity.User">
        select a.*
        from user a
        where a.id ={id}
    </select>

    <select id="selectByIn" parameterType="java.lang.Long"
            resultType="com.lhz.sharding.model.entity.User">
        select a.*
        from user a
        where a.id IN
        <foreach collection="ids" item="id" open="(" close=")" separator=",">
           {id}
        </foreach>
    </select>

    <select id="listByRange"
            resultType="com.lhz.sharding.model.entity.User">
        select a.*
        from user a
        <!--where a.id >{min}-->
        <!--where a.id <{max}-->
        where a.id >={min} and a.id <={max}
        <!-- where a.id between{min} and{max}-->
    </select>

    <update id="updateById" parameterType="java.lang.Long">
        update
            user
        set name ='测试名称'
        where id ={id}
    </update>

    <delete id="deleteById" parameterType="java.lang.Long">
        delete
        from user
        where id ={id}
    </delete>

    <insert id="insert" parameterType="com.lhz.sharding.model.entity.User">
        insert into user(id, name, phone, email)
        values (#{id},{name},{phone},{email})
    </insert>

    <insert id="insertBatch" parameterType="com.lhz.sharding.model.entity.User">
        insert into user(id, name, phone, email)
        values
        <foreach collection="list" item="item" separator=",">
            (#{item.id},{item.name},{item.phone},{item.email})
        </foreach>
    </insert>
</mapper>

7、Service类

ComplexService:

@Service
public class ComplexService {
   
     
    @Resource
    private ComplexMapper complexMapper;
    /**
     * 根据ID查询
     *
     * @param id
     * @return
     */
    public User selectById(Long id) {
   
     

        // in匹配查询
        List<Long> ids = new ArrayList<>();
        ids.add(1L);
        ids.add(3L);
        ids.add(5L);
        List<User> list = complexMapper.selectByIn(ids);

        return complexMapper.selectById(id);
    }

    /**
     * 范围查询
     *
     * @param min
     * @param max
     * @return
     */
    public List<User> listByRange(Long min, Long max) {
   
     
        return complexMapper.listByRange(min, max);
    }

    /**
     * 根据ID删除
     *
     * @param id
     * @return
     */
    @ApiOperation(value = "根据ID删除", notes = "根据ID删除")
    @ApiOperationSupport(order = 15)
    @GetMapping("/deleteById")
    public int deleteById(Long id) {
   
     
        return complexMapper.deleteById(id);
    }

    /**
     * 根据ID更新
     *
     * @param id
     * @return
     */
    @ApiOperation(value = "根据ID更新", notes = "根据ID更新")
    @ApiOperationSupport(order = 20)
    @GetMapping("/updateById")
    public int updateById(Long id) {
   
     
        return complexMapper.updateById(id);
    }

    /**
     * 新增数据
     *
     * @return
     */
    @ApiOperation(value = "新增数据", notes = "新增数据")
    @ApiOperationSupport(order = 25)
    @GetMapping("/insert")
    public int insert() {
   
     
        // 模拟数据
        List<User> list = new ArrayList<>();
        for (long a = 311; a <= 320; a++) {
   
     
            User user = new User();
            user.setId(a);
            user.setName("测试名称-" + a);
            user.setPhone("176-" + a);
            user.setEmail("123@com-" + a);

            list.add(user);
        }

        // 批量新增
        complexMapper.insertBatch(list);

        // 单个新增
        User user = new User();
        user.setId(399L);
        user.setName("测试名称-" + 999);
        user.setPhone("176-" + 999);
        user.setEmail("123@com-" + 999);
        return complexMapper.insert(user);
    }
}

8、Controller类

ComplexController :

@RestController
@RequestMapping("standard")
public class ComplexController {
   
     

    @Resource
    private ComplexService complexService;

    /**
     * 根据ID查询
     *
     * @param id
     * @return
     */
    @GetMapping("/selectById")
    public User selectById(Long id) {
   
     
        return complexService.selectById(id);
    }
    /**
     * 范围查询
     *
     * @param min
     * @param max
     * @return
     */
    @GetMapping("/listByRange")
    public List<User> listByRange(Long min, Long max) {
   
     
        return complexService.listByRange(min, max);
    }

    /**
     * 根据ID删除
     *
     * @param id
     * @return
     */
    @GetMapping("/deleteById")
    public int deleteById(Long id) {
   
     
        return complexService.deleteById(id);
    }

    /**
     * 根据ID更新
     *
     * @param id
     * @return
     */
    @GetMapping("/updateById")
    public int updateById(Long id) {
   
     
        return complexService.updateById(id);
    }

    /**
     * 新增数据
     *
     * @return
     */
    @GetMapping("/insert")
    public int insert() {
   
     
        return complexService.insert();
    }
}

9、测试

1、删除、更新、精确查询:
 
2、范围查询:

2.1、只有最大值情况:

当sql中的查询只有最大值,即<=时,比如:

select * from user where id <{max}

这种情况则hasUpperBound=truehasLowerBound=false,并且需要处理最大值小于表数量以及最大值大于表数量的情况

 

2.2、只有最小值情况:

当sql中的查询只有最大值,即<=时,比如:

select * from user where id >{min}

这种情况则hasUpperBound=falsehasLowerBound=true,那么直接返回所有表即可

 

2.3、最大与最小值都存在情况:
当sql中的查询既有最大值又有最小值,比如:

select * from user where a.id >={min} and a.id <={max}
或者
select * from user where a.id between{min} and{max}

这种情况需要遍历最小值到最大值的区间,并且匹配满足要求的表名称,需要注意的是,如果遍历过程中满足要求的表已经覆盖了所有表,那么就直接返回所有表,不再继续遍历,这是为了方式查询区间过大,而分表不多,导致的过度遍历。

 
执行结果:

 

3、新增数据: