上一篇文章《SpringBoot实现多数据源（三）【AOP + 自定义注解】》

四、集成多个 Mybatis 框架

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实现步骤

1. 创建一个 dynamic_mybatis 的springboot项目，导入依赖
   • pom.xml

<dependencies>
    <!--jdbc-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <!--web-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--aop-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
    <!--mybatis-->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.4</version>
    </dependency>
    <!--druid-->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.2.8</version>
    </dependency>
    <!--mysql驱动-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.28</version>
    </dependency>
    <!--lombok-->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.24</version>
    </dependency>

</dependencies>

2. 配置文件
   • application.yml

spring:
  application:
    name: dynamic_datasource
  # 数据源
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    # 读数据源
    read:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/read?useSSL=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
      username: root
      password: 123456
    # 写数据源
    write:
      type: com.alibaba.druid.pool.DruidDataSource
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/write?useSSL=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
      username: root
      password: 123456
# 端口号
server:
  port: 3355

3. 实体类（这里省略增删查改的数据库操作）
   • People

package com.vinjcent.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@AllArgsConstructor
@NoArgsConstructor
@Data
public class People {

    private String name;

}

4. 配置读写分离的的MybatisConfiguration配置

• RMybatisConfiguration（读数据源）

package com.vinjcent.config.mybatis;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
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.PathMatchingResourcePatternResolver;

import javax.sql.DataSource;


/**
 * 读数据源配置
 * 1. 指定扫描mapper接口包
 * 2. 指定使用wSqlSessionFactory是哪个
 */
@Configuration
@MapperScan(basePackages = "com.vinjcent.mapper.read", sqlSessionFactoryRef = "rSqlSessionFactory")
public class RMybatisConfiguration {


    @Bean(name = "readDatasource")
    @ConfigurationProperties(prefix = "spring.datasource.read")
    public DataSource readDatasource() {
        // 底层会自动拿到spring.datasource中的配置,创建一个DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory rSqlSessionFactory(@Qualifier("readDatasource") DataSource dataSource) throws Exception {
        final SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);
        sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:com/vinjcent/mapper/read/*.xml"));
        /* 主库设置sql控制台打印 */
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setLogImpl(StdOutImpl.class);
        sqlSessionFactory.setConfiguration(configuration);
        sqlSessionFactory.setTypeAliasesPackage("com.vinjcent.pojo");
        return sqlSessionFactory.getObject();
    }
}

• WMybatisConfiguration（写数据源）

package com.vinjcent.config.mybatis;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
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.PathMatchingResourcePatternResolver;

import javax.sql.DataSource;


/**
 * 写数据源配置
 * 1. 指定扫描mapper接口包
 * 2. 指定使用wSqlSessionFactory是哪个
 */
@Configuration
@MapperScan(basePackages = "com.vinjcent.mapper.write", sqlSessionFactoryRef = "wSqlSessionFactory")
public class WMybatisConfiguration {


    @Bean(name = "writeDatasource")
    @ConfigurationProperties(prefix = "spring.datasource.write")
    public DataSource writeDatasource() {
        // 底层会自动拿到spring.datasource中的配置,创建一个DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory wSqlSessionFactory(@Qualifier("writeDatasource") DataSource dataSource) throws Exception {
        final SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);
        sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:com/vinjcent/mapper/write/*.xml"));
        /* 主库设置sql控制台打印 */
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setLogImpl(StdOutImpl.class);
        sqlSessionFactory.setConfiguration(configuration);
        sqlSessionFactory.setTypeAliasesPackage("com.vinjcent.pojo");
        return sqlSessionFactory.getObject();
    }
}

5. 读写mapper接口以及对应映射文件.xml

• RPeopleMapper

package com.vinjcent.mapper.read;

import com.vinjcent.pojo.People;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface RPeopleMapper {

    List<People> list();

}

<?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.vinjcent.mapper.read.RPeopleMapper">

    <select id="list" resultType="People">
        select * from `people`
    </select>
</mapper>

• WPeopleMapper

package com.vinjcent.mapper.write;

import com.vinjcent.pojo.People;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface WPeopleMapper {

    boolean save(People people);

}

<?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.vinjcent.mapper.write.WPeopleMapper">


    <insert id="save">
        insert into `people`(name)
        values (#{name});
    </insert>

</mapper>

5. Service层
   • PeopleServiceImpl

package com.vinjcent.service.impl;

import com.vinjcent.mapper.read.RPeopleMapper;
import com.vinjcent.mapper.write.WPeopleMapper;
import com.vinjcent.pojo.People;
import com.vinjcent.service.PeopleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class PeopleServiceImpl implements PeopleService {

    private final PeopleService peopleService;

    @Autowired
    public PeopleController(PeopleService peopleService) {
        this.peopleService = peopleService;
    }

	// 读
    @GetMapping("/list")
    public List<People> getAllPeople() {
        return peopleService.list();
    }

    // 写
    @GetMapping("/insert")
    public String addPeople() {
        peopleService.save(new People("vinjcent"));
        return "添加成功";
    }
}

6. 测试接口

• PeopleController

package com.vinjcent.controller;

import com.vinjcent.mapper.read.RPeopleMapper;
import com.vinjcent.mapper.write.WPeopleMapper;
import com.vinjcent.pojo.People;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("people")
public class PeopleController {

    private final WPeopleMapper wPeopleMapper;

    private final RPeopleMapper rPeopleMapper;

    @Autowired
    public PeopleController(WPeopleMapper wPeopleMapper, RPeopleMapper rPeopleMapper) {
        this.wPeopleMapper = wPeopleMapper;
        this.rPeopleMapper = rPeopleMapper;
    }


    @GetMapping("/list")
    public List<People> getAllPeople() {
        return rPeopleMapper.list();
    }

    @GetMapping("/insert")
    public String addPeople() {
        wPeopleMapper.save(new People("vinjcent"));
        return "添加成功";
    }

}

7. 运行并测试接口

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