前言

多数据源是一种常见的技术需求，它允许应用程序连接和操作多个不同的数据库或数据源。

使用该方式配置数据源就是，将连接不同数据的Mapper有Mapping文件放到不同的目录下，在配置DataSource进行手动指定，使用时通过不同目录的Mapper访问不同的数据库连接，达到多数据源配置的目的；

1、创建数据库(表)

分别在mysql中创建两个库：system、log，并且创建对应的表(根据项目实际情况的定)，如下：

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2、yaml配置

spring:application:name: quartzdatasource:# 数据源一system:driverClassName: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3307/system?useUnicode=true&useSSL=false&zeroDateTimeBehavior=convertToNull&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghaiusername: rootpassword: lhzlx# 数据源二log:driverClassName: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://127.0.0.1:3307/log?useUnicode=true&useSSL=false&zeroDateTimeBehavior=convertToNull&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Asia/Shanghaiusername: rootpassword: lhzlx# hikari连接池type: com.zaxxer.hikari.HikariDataSourcehikari:#最大连接数，小于等于0会被重置为默认值10；大于零小于1会被重置为minimum-idle的值maximum-pool-size: 10#最小空闲连接，默认值 10，小于0或大于maximum-pool-size，都会重置为maximum-pool-sizeminimum-idle: 2#连接超时时间:毫秒，小于250毫秒，否则被重置为默认值30秒connection-timeout: 60000#空闲连接超时时间，默认值600000ms（10分钟），大于等于max-lifetime且max-lifetime>0，会被重置为0；#不等于0且小于10秒，会被重置为10秒。#只有空闲连接数大于最大连接数且空闲时间超过该值，才会被释放(自动释放过期链接)idle-timeout: 600000#连接最大存活时间.不等于0且小于30秒，会被重置为默认值30分钟.设置应该比mysql设置的超时时间短max-lifetime: 640000#连接测试查询connection-test-query: SELECT 1#mapper 别名扫描
mybatis:type-aliases-package: com.lhz.demo.model.entity#数据库类型configuration.database-id: mysql#自动驼峰转换configuration.map-underscore-to-camel-case: true

注意： 在使用hikari作为连接池时，如果配置多数据源需要将url修改为jdbc-url，使用druid作为连接池则不需要修改；否则会出现jdbcUrl is required with driverClassName错误；

3、数据源配置

配置LogDataSourceConfig与SystemDataSourceConfig

@MapperScan(basePackages = "com.lhz.demo.mapper.system", sqlSessionFactoryRef = "systemSqlSessionFactory")
@Configuration
public class SystemDataSourceConfig {//  @Primary ：默认数据源@Primary@Bean("systemDataSource")// yaml文件中配置的数据源前缀@ConfigurationProperties(prefix = "spring.datasource.system")public DataSource getSystemDataSource(){return DataSourceBuilder.create().build();}@Primary@Bean("systemSqlSessionFactory")public SqlSessionFactory systemSqlSessionFactory(@Qualifier("systemDataSource") DataSource dataSource) throws Exception {SqlSessionFactoryBean bean = new SqlSessionFactoryBean();bean.setDataSource(dataSource);// 配置mapping所在目录bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mappers/system/*.xml"));return bean.getObject();}@Primary@Bean("systemSqlSessionTemplate")public SqlSessionTemplate systemSqlSessionTemplate(@Qualifier("systemSqlSessionFactory") SqlSessionFactory sqlSessionFactory){return new SqlSessionTemplate(sqlSessionFactory);}
}

@Configuration
@MapperScan(basePackages = "com.lhz.demo.mapper.log", sqlSessionFactoryRef = "logSqlSessionFactory")
public class LogDataSourceConfig {@Bean("logDataSource")// yaml文件中配置的数据源前缀@ConfigurationProperties(prefix = "spring.datasource.log")public DataSource getLogDataSource(){return DataSourceBuilder.create().build();}@Bean("logSqlSessionFactory")public SqlSessionFactory logSqlSessionFactory(@Qualifier("logDataSource") DataSource dataSource) throws Exception {SqlSessionFactoryBean bean = new SqlSessionFactoryBean();bean.setDataSource(dataSource);// 配置mapping所在目录bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mappers/log/*.xml"));return bean.getObject();}@Bean("logSqlSessionTemplate")public SqlSessionTemplate logSqlSessionTemplate(@Qualifier("logSqlSessionFactory") SqlSessionFactory sqlSessionFactory){return new SqlSessionTemplate(sqlSessionFactory);}
}

4、mappering

在resources/mappers/log目录下创建LogMapper.xml

<?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.lhz.demo.mapper.log.LogMapper"><select id="selectAll" resultType="com.lhz.demo.model.entity.TbLog">select * from tb_log</select>
</mapper>

在resources/mappers/system目录下创建SystemMapper.xml

<?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.lhz.demo.mapper.system.SysMapper"><select id="selectAll" resultType="com.lhz.demo.model.entity.TbSystem">select * from tb_system</select>
</mapper>

在这里插入图片描述

5、mapper

在com.lhz.demo.mapper.log目录下创建LogMapper

@Mapper
public interface LogMapper {List<TbLog> selectAll();
}

在com.lhz.demo.mapper.system目录下创建SystemMapper

@Mapper
public interface SysMapper {List<TbSystem> selectAll();
}

6、controllrt

@RestController
@RequestMapping("/test")
@Slf4j
public class TestController {@Resourceprivate SysMapper sysMapper;@Resourceprivate LogMapper logMapper;/*** 查询system库* @return*/@GetMapping("/sys")public Object sys() {return sysMapper.selectAll();}/*** 查询log库* @return*/@GetMapping("/log")public Object log() {return logMapper.selectAll();}
}