基于ShardingJDBC的分库分表

因产品推广发展，业务对数据库的访问压力变大（数据库为虚拟机），单表已无力支撑，综合考虑对主要的大表做了分库分表。本文简要介绍分库分表实现过程。

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一、分库分表技术选型

数据库使用的是MySQL，分库分表方式最终从“基于Mycat中间件分库分表”和“基于ShardingJDBC分库分表”中二选一。因业务目标TPS较高，考虑到Mycat本身也可能成为分库分表的瓶颈（访问模型如图），最终采用了ShardingJDBC做分库分表。

二、设计实现

1.拆分设计

业务表中量不大的表，例如不超过百万记录的表，不做分库分表，固定在一个分库的表中。

业务表中量大的表做分库分表，此处以一张表为例。根据极限目标数据存储量100亿、单表存放最多1000万数据等考虑，拆分成128张表，因服务器有限，MySQL采用4主4从的部署方式，每台MySQL部署4个库（后续也可拆分成8主8从或16主16从，只需迁移数据及更新应用配置的访问数据库URL即可），每个库中分8张表，共计4*4*8=128张表。

2.分库分表实现

注：项目框架为SpringCloud，DAO层框架为Mybatis，数据库连接采用的Druid。

（1）建库建表

原单库表中不需要分库分表的表不做改动（确保最小改动），作为默认库表（假定原名为db），另建15个MySQL分库（如命名为db1 ~ db15），合计16个MySQL库。每个库中建8张分表（如命名为device0 ~ device7）。

（2）主要引入ShardingJDBC工具包

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

（3）分库配置

spring:
  shardingsphere:
    datasource:
      names: db,db1,db2,db3,db4,db5,db6,db7,db8,db9,db10,db11,db12,db13,db14,db15
      db0:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL1的IP:端口}/db?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db1:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL1的IP:端口}/db1?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db2:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL1的IP:端口}/db2?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db3:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL1的IP:端口}/db3?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db4:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL2的IP:端口}/db4?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db5:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL2的IP:端口}/db5?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db6:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL2的IP:端口}/db6?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db7:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL2的IP:端口}/db7?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db8:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL3的IP:端口}/db8?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db9:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL3的IP:端口}/db9?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db10:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL3的IP:端口}/db10?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db11:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL3的IP:端口}/db11?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db12:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL4的IP:端口}/db12?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db13:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL4的IP:端口}/db13?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db14:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL4的IP:端口}/db14?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false
      db15:
        driver-class-name: com.mysql.jdbc.Driver
        username: xxxx
        password: '{cipher}xxxxxxxxxxx'
        url: jdbc:mysql://{MySQL4的IP:端口}/db15?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false
        type: com.alibaba.druid.pool.DruidDataSource
        initialSize: 4
        minIdle: 8
        maxActive: 128
        maxWait: 1500
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        sql-script-encoding: UTF-8
        stat-view-servlet:
          enabled: false

（4）分片策略

分片原理：根据需要操作的字段devId hash到对应的分库号（0 ~ 15）即找到对应的分库，再根据devIdhash到对应的表号（0 ~ 7）即找到对应的表。

分库规则：(int)(Math.abs(devId.hashCode()) % 128 / 8)，即将待操作的字段hashCode绝对值与128取余，得到0~127间的值，再除以8，则得到0~15间的值，即分库号。

分表规则：(int)(Math.abs(devId.hashCode()) % 128 % 8)，即将待操作的字段hashCode绝对值与128取余，得到0~127间的值，再与8取余，则得到0~7间的值，即分表号。

示例采用的注解方式注入数据源，详细代码如下：

import java.io.IOException;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.shardingsphere.api.config.sharding.ShardingRuleConfiguration;
import org.apache.shardingsphere.api.config.sharding.TableRuleConfiguration;
import org.apache.shardingsphere.api.config.sharding.strategy.InlineShardingStrategyConfiguration;
import org.apache.shardingsphere.shardingjdbc.api.ShardingDataSourceFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.ResourcePatternResolver;
import com.alibaba.druid.pool.DruidDataSource;
import com.google.common.collect.Lists;

/**
 * @author [email protected]
 * @date 2020年3月4日 下午9:08:04
 * @version 
 */
@Configuration
@MapperScan(basePackages = "com.cn.iot.dao.mapper.report", sqlSessionTemplateRef = "sqlSessionTemplate")
public class Dal {

    @Autowired
    private ResourcePatternResolver resourceLoader;

    /**
     * 数据库分片规则
     * @return
     */
    @Bean(name = "shardingRuleConfig")
    //@ConfigurationProperties(prefix = "spring.shardingsphere.sharding.tables")
    public ShardingRuleConfiguration shardingRuleConfig() {
       /* 
        * 配置device表分片规则 - 16个分库（db0 ~ db15），每个库中分8张表（device0 ~ device7）
        */
        TableRuleConfiguration deviceTableRuleConfig = new TableRuleConfiguration("device",
                "db${0..15}.device${0..7}");
        // 配置分库 + 分表策略
        deviceTableRuleConfig
                .setDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("devId",
                        "db${(int)(Math.abs(devId.hashCode()) % 128 / 8)}"));
        deviceTableRuleConfig
                .setTableShardingStrategyConfig(new InlineShardingStrategyConfiguration("devId",
                        "device${(int)(Math.abs(devId.hashCode()) % 128 % 8)}"));
        

        
        ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
        // 设置默认数据源
        shardingRuleConfig.setDefaultDataSourceName("db0");
        shardingRuleConfig.setTableRuleConfigs(Lists.newArrayList(gatewayTableRuleConfig,
                macIndexTableRuleConfig, deviceTableRuleConfig));
        return shardingRuleConfig;
    }

    //---------------------------------默认分库db0---------------------------------------
    /**
     * 默认数据库 db0
     * @return
     */
    @Bean(name = "dataSource0", destroyMethod = "close")
    @Primary
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db0")
    public DataSource druid() {
        return new DruidDataSource();
    }

    //---------------------------------分库db 1 ~ 15---------------------------------------
    /**
     * db1
     * @return
     */
    @Bean(name = "dataSource1", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db1")
    public DataSource druid1() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource2", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db2")
    public DataSource druid2() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource3", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db3")
    public DataSource druid3() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource4", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db4")
    public DataSource druid4() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource5", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db5")
    public DataSource druid5() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource6", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db6")
    public DataSource druid6() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource7", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db7")
    public DataSource druid7() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource8", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db8")
    public DataSource druid8() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource9", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db9")
    public DataSource druid9() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource10", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db10")
    public DataSource druid10() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource11", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db11")
    public DataSource druid11() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource12", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db12")
    public DataSource druid12() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource13", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db13")
    public DataSource druid13() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource14", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db14")
    public DataSource druid14() {
        return new DruidDataSource();
    }

    /**
     * @return
     */
    @Bean(name = "dataSource15", destroyMethod = "close")
    @ConfigurationProperties(prefix = "spring.shardingsphere.datasource.db15")
    public DataSource druid15() {
        return new DruidDataSource();
    }

    /**
     * 
     * @param dataSource0
     * @param dataSource1
     * @param dataSource2
     * @param dataSource3
     * @param dataSource4
     * @param dataSource5
     * @param dataSource6
     * @param dataSource7
     * @param dataSource8
     * @param dataSource9
     * @param dataSource10
     * @param dataSource11
     * @param dataSource12
     * @param dataSource13
     * @param dataSource14
     * @param dataSource15
     * @param shardingRuleConfig
     * @return
     * @throws SQLException
     */
    @Bean(name = "buildDataSource")
    public DataSource buildDataSource(@Qualifier("dataSource0") DataSource dataSource0,
                                      @Qualifier("dataSource1") DataSource dataSource1,
                                      @Qualifier("dataSource2") DataSource dataSource2,
                                      @Qualifier("dataSource3") DataSource dataSource3,
                                      @Qualifier("dataSource4") DataSource dataSource4,
                                      @Qualifier("dataSource5") DataSource dataSource5,
                                      @Qualifier("dataSource6") DataSource dataSource6,
                                      @Qualifier("dataSource7") DataSource dataSource7,
                                      @Qualifier("dataSource8") DataSource dataSource8,
                                      @Qualifier("dataSource9") DataSource dataSource9,
                                      @Qualifier("dataSource10") DataSource dataSource10,
                                      @Qualifier("dataSource11") DataSource dataSource11,
                                      @Qualifier("dataSource12") DataSource dataSource12,
                                      @Qualifier("dataSource13") DataSource dataSource13,
                                      @Qualifier("dataSource14") DataSource dataSource14,
                                      @Qualifier("dataSource15") DataSource dataSource15,
                                      @Qualifier("shardingRuleConfig") ShardingRuleConfiguration shardingRuleConfig)
            throws SQLException {
        Map<String, DataSource> dataSourceMap = new HashMap<String, DataSource>();
        dataSourceMap.put("db0", dataSource0);
        dataSourceMap.put("db1", dataSource1);
        dataSourceMap.put("db2", dataSource2);
        dataSourceMap.put("db3", dataSource3);
        dataSourceMap.put("db4", dataSource4);
        dataSourceMap.put("db5", dataSource5);
        dataSourceMap.put("db6", dataSource6);
        dataSourceMap.put("db7", dataSource7);
        dataSourceMap.put("db8", dataSource8);
        dataSourceMap.put("db9", dataSource9);
        dataSourceMap.put("db10", dataSource10);
        dataSourceMap.put("db11", dataSource11);
        dataSourceMap.put("db12", dataSource12);
        dataSourceMap.put("db13", dataSource13);
        dataSourceMap.put("db14", dataSource14);
        dataSourceMap.put("db15", dataSource15);
        return ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig,
                new Properties());
    }

    /**
     * 
     * @param buildDataSource
     * @return
     * @throws Exception
     */
    @Bean(name = "sqlSessionTemplate")
    @Primary
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("buildDataSource") DataSource buildDataSource)
            throws Exception {
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        factory.setDataSource(buildDataSource);
        factory.setConfigLocation(
                resourceLoader.getResource("classpath:mybatis/sqlmap-config.xml"));
        try {
            factory.setMapperLocations(
                    resourceLoader.getResources("classpath*:mybatis/*Mapper.xml"));
        } catch (IOException never) {
            throw new RuntimeException(never);
        }
        factory.afterPropertiesSet();
        SqlSessionTemplate template = new SqlSessionTemplate(factory.getObject());
        return template;
    }

}

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总结

基于ShardingJDBC分库分表需要结合业务进行设计实现，在性能上相比Mycat有优势，主要是不用担心Mycat瓶颈问题，但有少量代码改造。关于分片策略，本文仅采用了行表达式分片策略，实际的分片策略还有多种，具体可参考官网http://shardingsphere.apache.org/index_zh.html。