【ShardingSphere】springboot整合shardingjdbc使用精确分片算法自定义分库分表

爱被打了一巴掌 2022-10-06 05:56 321阅读 0赞

> 上两篇文章讲到了两种分库分表的方式，这两种方式可以归结为一种类型，都是通过配置的形式来分片数据。本文我们继续讲解一种新的方式来分片数据，除了配置的形式外，shardingjdbc还支持通过代码来自定义规则。

--------------------

### 自定义规则 ###

之前我们实现了id取模和按日期分库分表，这里我们为了展示技术，还是继续按照日期分表，不过这里通过代码来自定义。在开始写代码之前，我们先将分库分表规则定义好。  
这里我们建立两个库ds0,ds1。每个库建立表t\_order2021、t\_order2022两个表，语句如下：

CREATE TABLE `t_order2021` (
      `id` bigint(32) NOT NULL,
      `user_id` int(11) DEFAULT NULL,
      `order_id` int(11) DEFAULT NULL,
      `cloumn` varchar(45) DEFAULT NULL,
      `day_date` char(8) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
    CREATE TABLE `t_order2022` (
      `id` bigint(32) NOT NULL,
      `user_id` int(11) DEFAULT NULL,
      `order_id` int(11) DEFAULT NULL,
      `cloumn` varchar(45) DEFAULT NULL,
      `day_date` char(8) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

### 搭建工程 ###

基本环境准备好了，我们就可以开始我们的工程搭建了。这里搭建一个springboot工程，然后整合mybatis和shardingjdbc。具体依赖如下：

<properties>
        <java.version>1.8</java.version>
        <sharding-sphere.version>4.1.1</sharding-sphere.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    
        <dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <version>${sharding-sphere.version}</version>
        </dependency>
    
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
        </dependency>
    
        
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>
    
        
        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>4.0.3</version>
        </dependency>
    
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.25</version>
        </dependency>
    
        
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>
    </dependencies>

### 上手sharding配置 ###

添加mybatis和shardingjdbc的配置

server.port=10080
    
    spring.shardingsphere.datasource.names=ds0,ds1
    
    # 配置第一个数据库
    spring.shardingsphere.datasource.ds0.type=com.zaxxer.hikari.HikariDataSource
    spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
    spring.shardingsphere.datasource.ds0.jdbc-url=jdbc:mysql://localhost:3306/ds0
    spring.shardingsphere.datasource.ds0.username=root
    spring.shardingsphere.datasource.ds0.password=root
    
    # 配置第二个数据库
    spring.shardingsphere.datasource.ds1.type=com.zaxxer.hikari.HikariDataSource
    spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
    spring.shardingsphere.datasource.ds1.jdbc-url=jdbc:mysql://localhost:3306/ds1
    spring.shardingsphere.datasource.ds1.username=root
    spring.shardingsphere.datasource.ds1.password=root
    
    # 配置t_order表的分库策略
    spring.shardingsphere.sharding.tables.t_order.database-strategy.standard.sharding-column=id
    # 自定义分库策略
    spring.shardingsphere.sharding.tables.t_order.database-strategy.standard.precise-algorithm-class-name=com.example.test.config.MyDbPreciseShardingAlgorithm
    
    # 配置t_order的分表策略
    spring.shardingsphere.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{2021..2022}
    spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column=day_date
    # 自定义分表策略
    spring.shardingsphere.sharding.tables.t_order.table-strategy.standard.precise-algorithm-class-name=com.example.test.config.MyTablePreciseShardingAlgorithm
    
    # 添加t_order表的id生成策略
    spring.shardingsphere.sharding.tables.t_order.key-generator.column=id
    spring.shardingsphere.sharding.tables.t_order.key-generator.type=SNOWFLAKE
    
    # 打开sql输出日志
    spring.shardingsphere.props.sql.show=true
    
    # mybatis配置
    mybatis.mapper-locations=classpath:mapping/*.xml
    mybatis.type-aliases-package=com.example.test.po
    
    # 配置日志级别
    logging.level.com.echo.shardingjdbc.dao=DEBUG

启动类上添加mybatis的mapper扫描配置@MapperScan(“com.example.test.dao”)

> 在以上配置中，我们定义了自定义配置的类路径，接下来我们会去编写这两个自定义配置的内容。

### 编写自定义规则类 ###

在文章开头我们就已经定义了规则，现在我们来实现这个规则。根据我们的规则我们可以选择精确分片算法来实现，具体代码如下：

package com.example.test.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.apache.shardingsphere.api.sharding.standard.PreciseShardingAlgorithm;
    import org.apache.shardingsphere.api.sharding.standard.PreciseShardingValue;
    
    import java.util.Collection;
    
    /**
     * 自定义分库规则类
     * @author echo
     * @date 2021/6/10 0010 上午 10:09
     */
    @Slf4j
    public class MyDbPreciseShardingAlgorithm implements PreciseShardingAlgorithm<Long> {
        
    
        /**
         * 分片策略
         *
         * @param availableTargetNames 所有的数据源
         * @param shardingValue        SQL执行时传入的分片值
         * @return 返回
         */
        @Override
        public String doSharding(Collection<String> availableTargetNames, PreciseShardingValue<Long> shardingValue) {
        
            // 真实节点
            availableTargetNames.forEach(item -> log.info("actual node db:{}", item));
    
            log.info("logic table name:{},rout column:{}", shardingValue.getLogicTableName(), shardingValue.getColumnName());
    
            //精确分片
            log.info("column value:{}", shardingValue.getValue());
    
            for (String each : availableTargetNames) {
        
                Long value = shardingValue.getValue();
                if (("ds" + value % 2).equals(each)) {
        
                    return each;
                }
            }
    
            return null;
        }
    
    }

package com.example.test.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.apache.shardingsphere.api.sharding.standard.PreciseShardingAlgorithm;
    import org.apache.shardingsphere.api.sharding.standard.PreciseShardingValue;
    
    import java.util.Collection;
    
    /**
     * 自定义分表规则类
     *
     * @author echo
     * @date 2021/6/10 0010 上午 10:09
     */
    @Slf4j
    public class MyTablePreciseShardingAlgorithm implements PreciseShardingAlgorithm<String> {
        
    
        @Override
        public String doSharding(Collection<String> availableTargetNames, PreciseShardingValue<String> shardingValue) {
        
            // 真实节点
            availableTargetNames.forEach(item -> log.info("actual node table:{}", item));
    
            log.info("logic table name:{},rout column:{}", shardingValue.getLogicTableName(), shardingValue.getColumnName());
    
            // 精确分片
            log.info("column value:{}", shardingValue.getValue());
    
            for (String each : availableTargetNames) {
        
                if (("t_order" + shardingValue.getValue()).equals(each)) return each;
            }
    
            return null;
        }
    
    }

### 上测试代码 ###

按照之前文章的套路，我们写点测试代码，代码如下：

package com.example.test.controller;
    
    import com.example.test.po.TOrder;
    import com.example.test.service.TOrderService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.List;
    
    /**
     * @author echo
     * @date 2021/6/3 0003 下午 16:37
     */
    @RestController
    @RequestMapping("/order")
    public class TOrderController {
        
    
        @Autowired
        private TOrderService tOrderService;
    
        @PostMapping("/save")
        public String save(@RequestBody TOrder tOrder) {
        
            tOrderService.save(tOrder);
            return "success";
        }
    
        @PostMapping("/delete")
        public String delete(@RequestParam(value = "id") Long id) {
        
            tOrderService.delete(id);
            return "success";
        }
    
        @PostMapping("/update")
        public int update(@RequestBody TOrder tOrder) {
        
            return tOrderService.update(tOrder);
        }
    
        @GetMapping("/getList")
        public List<TOrder> getList() {
        
            return tOrderService.getList();
        }
    
    }
    
    public interface TOrderService {
        
        void save(TOrder tOrder);
    
        void delete(Long id);
    
        int update(TOrder tOrder);
    
        List<TOrder> getList();
    }
    
    @Service
    public class TOrderServiceImpl implements TOrderService {
        
    
        @Autowired
        private TOrderDao tOrderDao;
    
        @Override
        public void save(TOrder tOrder) {
        
            tOrderDao.insert(tOrder);
        }
    
        @Override
        public void delete(Long id) {
        
            tOrderDao.delete(id);
        }
    
        @Override
        public int update(TOrder tOrder) {
        
            return tOrderDao.update(tOrder);
        }
    
        @Override
        public List<TOrder> getList() {
        
            return tOrderDao.getList();
        }
    
    }
    
    public interface TOrderDao {
        
    
        void insert(TOrder tOrder);
    
        List<TOrder> getList();
    
        void delete(Long id);
    
        int update(TOrder tOrder);
    }
    
    <?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.example.test.dao.TOrderDao">
        <resultMap id="BaseResultMap" type="com.example.test.po.TOrder">
            <id column="id" jdbcType="BIGINT" property="id"/>
            <result column="user_id" jdbcType="INTEGER" property="userId"/>
            <result column="order_id" jdbcType="INTEGER" property="orderId"/>
            <result column="cloumn" jdbcType="VARCHAR" property="cloumn"/>
            <result column="day_date" jdbcType="CHAR" property="dayDate"/>
        </resultMap>
        <sql id="Base_Column_List">
            id, user_id, order_id, cloumn, day_date
        </sql>
    
        <insert id="insert" parameterType="com.example.test.po.TOrder">
            insert into t_order (user_id, order_id, cloumn, day_date) value (#{
        userId}, #{
        orderId}, #{
        cloumn}, #{
        dayDate})
        </insert>
    
        <select id="getList" resultMap="BaseResultMap">
            select
            <include refid="Base_Column_List"/>
            from t_order
        </select>
    
        <delete id="delete" parameterType="java.lang.Long">
            delete from t_order
            where id = #{
        id,jdbcType=BIGINT}
        </delete>
    
        <update id="update" parameterType="com.example.test.po.TOrder">
            update t_order
            set
              cloumn = #{
        cloumn,jdbcType=VARCHAR},
              order_id = #{
        orderId,jdbcType=INTEGER},
              user_id = #{
        userId,jdbcType=INTEGER}
            where id = #{
        id,jdbcType=BIGINT}
        </update>
    </mapper>

### 完成之后我们可以测试一下 ###

调用接口http://localhost:3306/order/save,我们会发现，我们的数据根据我们既定的规则进入了相应的表  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3hsZWNobw_size_16_color_FFFFFF_t_70]

### 总结 ###

*  在配置的时候，版本问题会对配置造成一定的影响，所以如果配置相应内容的话， 要注意版本信息对应的官网配置规则
 *  不同规则对应的配置规则不一，比如这里用的精确分片算法，需要找到对应的精确分片算法的配置内容，不然不会生效

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