spring boot 配置 mybatis-plus多数据源

简介

Mybatis-puls 多数据源的使用，采用的是官方提供的dynamic-datasource-spring-boot-starter包的 @DS 注解，具体可以参考官网：

https://gitee.com/baomidou/dynamic-datasource-spring-boot-starter

pom.xml文件引入如下依赖

主要引入dynamic-datasource-spring-boot-starter包

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.olive</groupId><artifactId>mybatis-plus-multip-datasource</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>mybatis-multip-datasource</name><url>http://maven.apache.org</url><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.5.14</version><relativePath /> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.5.2</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.2</version></dependency></dependencies>
</project>

配置两个数据源

分别为第一个主数据源(primary)，第二数据源(slave_1)，具体配置如下：

# 基本配置
server:port: 8080# 数据库
spring:datasource:dynamic:primary: master #设置默认的数据源或者数据源组,默认值即为masterstrict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源datasource:master:url: jdbc:mysql://127.0.0.1:3306/db01?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=trueusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver # 3.2.0开始支持SPI可省略此配置slave_1:url: jdbc:mysql://127.0.0.1:3306/crm72?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=trueusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Drivermybatis-plus:mapper-locations: mapper/*.xmltype-aliases-package: com.olive.entityconfiguration:map-underscore-to-camel-case: truelog-impl: org.apache.ibatis.logging.stdout.StdOutImpl

创建学生与老师实体类

学生实体类

package com.olive.entity;import java.io.Serializable;import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;@TableName("t_student")
@Data
public class StudentDO implements Serializable{@TableId(value="id", type = IdType.AUTO)private Long id;@TableField("user_name")private String name;@TableField("sex")private int sex;@TableField("grade")private String grade;
}

老师实体类

package com.olive.entity;import java.io.Serializable;import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;@Data
@TableName("t_teacher")
public class TeacherDO implements Serializable {@TableId(value = "id", type = IdType.AUTO)private Long id;@TableField("user_name")private String name;@TableField("sex")private int sex;@TableField("office")private String office;
}

数据库持久类

StudentMapper持久类

package com.olive.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.olive.entity.StudentDO;
import org.apache.ibatis.annotations.Mapper;@Mapper
public interface StudentMapper extends BaseMapper<StudentDO> {}

TeacherMapper持久类

package com.olive.mapper;import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.olive.entity.TeacherDO;
import org.apache.ibatis.annotations.Mapper;@DS("slave_1")
@Mapper
public interface TeacherMapper extends BaseMapper<TeacherDO> {}

以上，两个持久类的实现都是继承BaseMapper基类，该类提供了基本的增删改查的方法；要注意的是，TeacherMapper 类使用了@DS("slave_1")指定了数据源；而StudentMapper没有指定，使用的是默认的数据源。

服务类的实现

先定义操作学生和老师的两个接口

StudentService接口

package com.olive.service;import com.baomidou.mybatisplus.extension.service.IService;
import com.olive.entity.StudentDO;public interface StudentService extends IService<StudentDO> {
}

TeacherService接口

package com.olive.service;import com.baomidou.mybatisplus.extension.service.IService;
import com.olive.entity.TeacherDO;public interface TeacherService extends IService<TeacherDO> {
}

再定义接口的实现类

StudentServiceImpl类

package com.olive.service.impl;import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.olive.entity.StudentDO;
import com.olive.mapper.StudentMapper;
import com.olive.service.StudentService;
import org.springframework.stereotype.Service;@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, StudentDO>implements StudentService {
}

TeacherServiceImpl类

package com.olive.service.impl;import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.olive.entity.TeacherDO;
import com.olive.mapper.TeacherMapper;
import com.olive.service.TeacherService;
import org.springframework.stereotype.Service;@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, TeacherDO>implements TeacherService {}