SpringBoot项目多数据源，mybatis 驼峰失效

1. 配置多数据源时，application.yml 的有关 mybatis 的配置是失效的，因为他不知道配置哪一个数据源

2. application.yml 配置文件

server:
  # 服务器的HTTP端口
  port: 8097

spring:
  # 配置数据源
  datasource:
    master:
      jdbc-url: jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC
      username: root
      password: root
      driver-class-name: com.mysql.cj.jdbc.Driver
    test:
      jdbc-url: jdbc:mysql://localhost:3306/test2?useSSL=false&serverTimezone=UTC
      username: root
      password: root
      driver-class-name: com.mysql.cj.jdbc.Driver

# MyBatis配置
mybatis:
    # 搜索指定包别名
    # (如果 typeAliasesPackage不进行配置，resultType就得写全名resultType="com.liyh.entity.User"，
    # 但是如果配置了别名,就可以不用写全路径直接写resultType="User"即可)
    type-aliases-package: com.liyh.entity
    # 配置mapper的扫描，找到所有的mapper.xml映射文件
    mapper-locations: classpath*:mapper/**/*Mapper.xml
    # 使用驼峰命名
    # 数据库表列：user_name
    # 实体类属性：userName
    configuration:
      map-underscore-to-camel-case: true

3. 解决方法一

3.1 application.yml 的配置驼峰保留

3.2 定义全局的配置

@Bean
@ConfigurationProperties(prefix = "mybatis.configuration")
public org.apache.ibatis.session.Configuration configuration() {
    return new org.apache.ibatis.session.Configuration();
}

3.3 在sqlSessionFactory中设置配置

@Primary
@Bean(name = "masterSqlSessionFactory")
public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource, org.apache.ibatis.session.Configuration configuration) throws Exception {
    SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
    sqlSessionFactoryBean.setDataSource(dataSource);
    sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*.xml"));
    sqlSessionFactoryBean.setTypeAliasesPackage("com.liyh.entity");
    sqlSessionFactoryBean.setConfiguration(configuration);
    return sqlSessionFactoryBean.getObject();
}

3.4 完整代码

package com.liyh.config;

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.boot.jdbc.DataSourceBuilder;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = {"com.liyh.mapper"}, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MybatisMasterConfig {

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

    /**
     * 配置事务管理器，不然事务不起作用
     *
     * @return
     */
    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(this.dataSource());
    }

    @Bean
    @ConfigurationProperties(prefix = "mybatis.configuration")
    public org.apache.ibatis.session.Configuration configuration() {
        return new org.apache.ibatis.session.Configuration();
    }

    @Primary
    @Bean(name = "masterSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource, org.apache.ibatis.session.Configuration configuration) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/*.xml"));
        sqlSessionFactoryBean.setTypeAliasesPackage("com.liyh.entity");
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }
}

4. 解决方法二

4.1 在 sqlSessionFactory 返回的 bean 中设置驼峰

sqlSessionFactoryBean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);

@Primary
@Bean(name = "masterSqlSessionFactory")
public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {
    SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
    sqlSessionFactoryBean.setDataSource(dataSource);
    sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*.xml"));
    sqlSessionFactoryBean.setTypeAliasesPackage("com.liyh.entity");
    sqlSessionFactoryBean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);
    return sqlSessionFactoryBean.getObject();
}

4.2 完整代码

package com.liyh.config;

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.boot.jdbc.DataSourceBuilder;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = {"com.liyh.mapper"}, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MybatisMasterConfig {

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

    /**
     * 配置事务管理器，不然事务不起作用
     *
     * @return
     */
    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(this.dataSource());
    }

    @Bean
    @ConfigurationProperties(prefix = "mybatis.configuration")
    public org.apache.ibatis.session.Configuration configuration() {
        return new org.apache.ibatis.session.Configuration();
    }

    @Primary
    @Bean(name = "masterSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource, org.apache.ibatis.session.Configuration configuration) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/*.xml"));
        sqlSessionFactoryBean.setTypeAliasesPackage("com.liyh.entity");
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }

}