SpringBoot3.0整合Mybatis-plus实现多数据源(重构类方式)
背景
前段时间在做一个数据中台的项目，系统用到了不同数据库中的数据。自己又不想手写JDBC连接，既然我有这个需求，那功能应该有人实现了，于是开始了网上搜了，搜索后发现基本都是讲读写分离、主备切换的，后面也查略了Mybatis-plus的官网，里面有这个功能，但好像是我组件的版本之间不兼容，导致出现了一些奇怪的bug，比如：Property ‘sqlSessionFactory‘ or ‘sqlSessionTemplate‘ are required或者是无法访问javax.servlet.http.HttpServlet 亦或者是Cannot resolve reference to bean ‘sqlSessionFactory‘ while setting constructor argument； nested exce。
总之，历经多重磨难总算是解决了
选择合适的组件版本能事半功倍。
组件版本
SpringBoot：3.0.0
JDK：19
MySQL：8.0.28
ClickHouse：21.4.6
clickhouse-jdbc：0.3.2-patch11
Mybatis-plus：3.5.7
dynamic-datasource：3.3.2
Druid：1.2.20
具体的pom.xml文件如下：
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<!--springboot3 开始，JDK最低要求要11，该项目用的是19-->
<version>3.0.0</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<!-- mysql-jdbc 驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<!-- clickhouse-jdbc 驱动-->
<dependency>
<groupId>com.clickhouse</groupId>
<artifactId>clickhouse-jdbc</artifactId>
<version>0.3.2-patch11</version>
<classifier>all</classifier>
<exclusions>
<exclusion>
<groupId>*</groupId>
<artifactId>*</artifactId>
</exclusion>
</exclusions>
</dependency>
<!--json web token-->
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt-api</artifactId>
<version>0.11.5</version>
</dependency>
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt-impl</artifactId>
<version>0.11.5</version>
</dependency>
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt-jackson</artifactId>
<version>0.11.5</version>
</dependency>
<!-- lombok 依赖 -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!-- mybatis-plus 依赖 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.7</version>
</dependency>
<!-- 动态配置多种数据源 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
<version>3.3.2</version>
</dependency>
<!-- druid启动器的依赖 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-3-starter</artifactId>
<version>1.2.20</version>
</dependency>
</dependencies>
至于为什么选择这些版本的组件，我也不知道🤐干活就是了。
需求
在同一个(Maven)项目中，根据不同请求，实现对不同数据库的操作，数据源选择Druid。
源码
项目代码整体架构
application.yml配置文件
spring:
datasource:
dynamic:
primary: system
strict: false
datasource:
system:
url: jdbc:mysql://xxx.xxx.xxx.xxx:xxxx/zhongtai_admin?useSSL=false&useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
username: xxxx
password: xxxx
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 600000
stat-view-servlet:
enabled: true
url-pattern: /druid/*
timeBetweenEvictionRunsMillis: 600000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
filters: stat,wall
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
report:
url: jdbc:clickhouse://xxx.xxx.xxx.xxx:xxxx/ads
enabled: true
driver-class-name: com.clickhouse.jdbc.ClickHouseDriver
type: com.alibaba.druid.pool.DruidDataSource
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 600000
stat-view-servlet:
enabled: true
url-pattern: /druid/*
timeBetweenEvictionRunsMillis: 600000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
filters: stat,wall
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
重写相关容器类
不知道大家是否还了解 SpringBoot 的自动装配原理（过程），像我们直接导 mybatis-plus-boot-starter 或是其他依赖，只要版本之间没问题，理论上是不会直接报：Property ‘sqlSessionFactory‘ or ‘sqlSessionTemplate‘ are required这些错误的，mybatis-plus 里是已经自动封装好了的。
ps：这个错误是我加了 dynamic-datasource-spring-boot-starter 后才报的，当时官网介绍很少（版本号什么的都没给），给了一个详细了解连接，跳转后要付费查略😡
遇到这些问题怎么办？只能自己重写相关方法，注入到bean中了。
SystemDataSourceConfig.java
ackage com.pzb.admin.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
import java.sql.SQLException;
/**
* @Description TODO 因为涉及多个数据源，现重写sqlSessionFactory等配置类，根据不同的mapper.xml映射文件，操作不同的数据源
* @Author zbpeng
* @DATE 2024/10/29 10:51
*/
@Configuration
@MapperScan(basePackages = "com.pzb.*.mapper", sqlSessionFactoryRef = "sqlSessionFactory")
public class SystemDataSourceConfig {
@Bean(name = "dataSource")
@ConfigurationProperties(prefix = "spring.datasource.dynamic.datasource.system")
@Primary
public DataSource dataSource() throws SQLException {
// 选择Druid 数据源
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setFilters("stat");
return druidDataSource;
}
@Bean(name = "sqlSessionFactory")
@Primary
public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource") DataSource dataSource) throws Exception {
MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setTypeAliasesPackage("com.pzb.*.bean");
bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/system/*.xml"));
//其他配置 ps:sqlSessionFactoryBean内可以配置yml的一切配置
MybatisConfiguration mybatisConfiguration = new MybatisConfiguration();
//是否下划线转驼峰
mybatisConfiguration.setMapUnderscoreToCamelCase(true);
//设置日志
mybatisConfiguration.setLogImpl(StdOutImpl.class);
bean.setConfiguration(mybatisConfiguration);
return bean.getObject();
}
@Bean(name = "transactionManager")
@Primary
public DataSourceTransactionManager transactionManager(@Qualifier("dataSource") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "sqlSessionTemplate")
@Primary
public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
ReportDataSourceConfig.java
package com.pzb.statistic.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
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.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
import java.sql.SQLException;
/**
* @Description TODO 因为涉及多个数据源，现重写sqlSessionFactory等配置类，根据不同的mapper.xml映射文件，操作不同的数据源
* @Author zbpeng
* @DATE 2024/10/29 10:55
*/
@Configuration
@MapperScan(basePackages = "com.pzb.statistic.mapper", sqlSessionFactoryRef = "sqlSessionFactory2")
public class ReportDataSourceConfig {
@Bean(name = "dataSource2")
@ConfigurationProperties(prefix = "spring.datasource.dynamic.datasource.report")
public DataSource dataSource() throws SQLException {
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setFilters("stat");
return druidDataSource;
}
@Bean(name = "sqlSessionFactory2")
public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSource2") DataSource dataSource) throws Exception {
MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setTypeAliasesPackage("com.pzb.report.bean");
bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/report/*.xml"));
//其他配置 ps:sqlSessionFactoryBean内可以配置yml的一切配置
MybatisConfiguration mybatisConfiguration = new MybatisConfiguration();
//是否下划线转驼峰
mybatisConfiguration.setMapUnderscoreToCamelCase(true);
//设置日志
mybatisConfiguration.setLogImpl(StdOutImpl.class);
bean.setConfiguration(mybatisConfiguration);
return bean.getObject();
}
@Bean(name = "transactionManager2")
public DataSourceTransactionManager transactionManager(@Qualifier("dataSource2") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "sqlSessionTemplate2")
public SqlSessionTemplate sqlSessionTemplate(@Qualifier("sqlSessionFactory2") SqlSessionFactory sqlSessionFactory) {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
后面就正常写就行了，根据你调的Mapper接口方法，找到对应的.xml映射文件，.xml映射文件绑定了不同的JDBC连接器，进而操作不同的数据库。（大概）
不知个位大佬有没有更好的解决方法方便讲解一下😭
参考资料：
https://blog.csdn.net/weixin_42675423/article/details/126932977
