3、spring-boot整合myBaits（多数据源）

1、添加依赖

         <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>

2、在application.properties添加相关配置

spring.datasource1.driver-class-name = com.mysql.jdbc.Driver
spring.datasource1.jdbc-url = jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource1.username = root
spring.datasource1.password = root


spring.datasource2.driver-class-name = com.mysql.jdbc.Driver
spring.datasource2.jdbc-url = jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource2.username = root
spring.datasource2.password = root

在配置文件中配置多个数据源的连接地址

3、配置数据来源

1. 数据源1

@Configuration
@MapperScan(basePackages = "com.hui.wang.spring.boot.mapper.datasource1", sqlSessionTemplateRef = "sqlSessionTemplate1")
public class DataSource1Config {

    @Bean(name = "dataSource1")
    @ConfigurationProperties(prefix = "spring.datasource1")
    @Primary
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactory1")
    @Primary
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource1") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "transactionManager1")
    @Primary
    public DataSourceTransactionManager dataSourceTransactionManager (@Qualifier("dataSource1") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "sqlSessionTemplate1")
    @Primary
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory1") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

2. 数据源2

@Configuration
@MapperScan(basePackages = "com.hui.wang.spring.boot.mapper.datasource2", sqlSessionTemplateRef = "sqlSessionTemplate2")
public class DataSource2Config {

    @Bean(name = "dataSource2")
    @ConfigurationProperties(prefix = "spring.datasource2")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "sqlSessionFactory2")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource2") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "transactionManager2")
    public DataSourceTransactionManager dataSourceTransactionManager (@Qualifier("dataSource2") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "sqlSessionTemplate2")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory2") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

springboot会自动加载spring.datasource.*相关配置，数据源就会自动注入到sqlSessionFactory中，sqlSessionFactory会自动注入到Mapper中，对了你一切都不用管了，直接拿起来使用就行了。

但是多个数据源的时候，需要将数据源的配置和mapper对应上，其中@MapperScan就是配置对应关系的，@MapperScan(basePackages = "com.neo.mapper.test1", sqlSessionTemplateRef = "test1SqlSessionTemplate")这句话的意思就是指明了扫描dao层，并且给dao层注入指定的SqlSessionTemplate。所有@Bean都需要按照命名指定正确。
@ ConfigurationProperties指定application.properties配置文件对应的数据源的key

4、Mapper代码

1. 数据源1的Mapper

package com.hui.wang.spring.boot.mapper.datasource1;

import java.util.List;

import com.hui.wang.spring.boot.domain.UserEntity;
import com.hui.wang.spring.boot.enums.UserSexEnum;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper1 {

    @Select("SELECT * FROM user")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    List<UserEntity> getAll();

    @Select("SELECT * FROM users WHERE id = #{id}")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    UserEntity getOne(Long id);

    @Insert("INSERT INTO users(userName,passWord,user_sex) VALUES(#{userName}, #{passWord}, #{userSex})")
    void insert(UserEntity userEntity);

    @Delete("DELETE FROM users WHERE id =#{id}")
    void delete(Long id);
}

2. 数据源2的Mapper

package com.hui.wang.spring.boot.mapper.datasource2;

import java.util.List;

import com.hui.wang.spring.boot.domain.UserEntity;
import com.hui.wang.spring.boot.enums.UserSexEnum;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper2 {

    @Select("SELECT * FROM user")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    List<UserEntity> getAll();

    @Select("SELECT * FROM users WHERE id = #{id}")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    UserEntity getOne(Long id);

    @Insert("INSERT INTO users(userName,passWord,user_sex) VALUES(#{userName}, #{passWord}, #{userSex})")
    void insert(UserEntity userEntity);

    @Delete("DELETE FROM users WHERE id =#{id}")
    void delete(Long id);

}

这样就配置好了多数据源的Mapper，直接在项目中使用对应的Mapper就行了