Springboot之 Mybatis 多数据源实现

简介

上篇讲解了 JPA 多数据源实现；这篇讲解一下 Mybatis 多数据源实现 。主要采用将不同数据库的 Mapper 接口分别存放到不同的 package，Spring 去扫描不同的包，注入不同的数据源来实现多数据源。原理跟 JPA 多数据源实现基本一致。

创建 mybatis-multip-datasource 项目

数据库脚本参考：

pom.xml文件引入如下依赖

<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>4.0.0modelVersion>
 
	<groupId>com.olivegroupId>
	<artifactId>mybatis-multip-datasourceartifactId>
	<version>0.0.1-SNAPSHOTversion>
	<packaging>jarpackaging>
 
	<name>jpa-multip-datasourcename>
	<url>http://maven.apache.orgurl>
 
	<parent>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-parentartifactId>
		<version>2.5.14version>
		<relativePath /> 
	parent>
 
	<properties>
		<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
		<maven.compiler.source>8maven.compiler.source>
		<maven.compiler.target>8maven.compiler.target>
	properties>
 
	<dependencies>
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-testartifactId>
			<scope>testscope>
		dependency>
		<dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>2.1.3version>
        dependency>
		
		<dependency>
			<groupId>mysqlgroupId>
			<artifactId>mysql-connector-javaartifactId>
		dependency>
 
		<dependency>
			<groupId>org.projectlombokgroupId>
			<artifactId>lombokartifactId>
		dependency>
		
		<dependency>
		    <groupId>org.springframework.bootgroupId>
		    <artifactId>spring-boot-starter-webartifactId>
		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(second)，具体配置如下：

# 基本配置
server:
  port: 8080
 
# 数据库
spring:
  datasource:
    primary:
      driver-class-name: com.mysql.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/db01?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=true
      username: root
      password: root
    second:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/crm72?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=true
      username: root
      password: root
 
  jackson:
    serialization:
      indent-output: true

配置数据源

DataSourceConfig配置

package com.olive.config;
 
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 javax.sql.DataSource;
 
/**
 * @Description: 数据源配置
 */
@Configuration
public class DataSourceConfig {
 
    @Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    @Primary
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean(name = "secondDataSource")
    @Qualifier("secondDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.second")
    public DataSource secondDataSource() {
        return DataSourceBuilder.create().build();
    }
}

PrimaryConfig数据源

/**
 * @Description: 主数据源配置
 */
@Configuration
@MapperScan(basePackages = "com.olive.mapper.primary",
            sqlSessionTemplateRef = "primarySqlSessionTemplate")
public class PrimaryConfig {
 
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;
 
    @Bean(name = "primarySqlSessionFactory")
    @Primary
    public SqlSessionFactory primarySqlSessionFacotory() throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(primaryDataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/primary/*.xml"));
        return sqlSessionFactoryBean.getObject();
    }
 
    @Bean(name = "primaryTransactionManager")
    @Primary
    public DataSourceTransactionManager primaryTransactionManager() {
        return new DataSourceTransactionManager(primaryDataSource);
    }
 
    @Bean(name = "primarySqlSessionTemplate")
    @Primary
    public SqlSessionTemplate primarySqlSessionTemplate(@Qualifier("primarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
 
}

SecondConfig数据源

/**
 * @Description: 主数据源配置
 */
@Configuration
@MapperScan(basePackages = "com.olive.mapper.second",
        sqlSessionTemplateRef = "secondSqlSessionTemplate")
public class SecondConfig {
 
    @Autowired
    @Qualifier("secondDataSource")
    private DataSource secondDataSource;
 
    @Bean(name = "secondSqlSessionFactory")
    public SqlSessionFactory secondSqlSessionFacotory() throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(secondDataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/second/*.xml"));
        return sqlSessionFactoryBean.getObject();
    }
 
    @Bean(name = "secondTransactionManager")
    public DataSourceTransactionManager secondTransactionManager() {
        return new DataSourceTransactionManager(secondDataSource);
    }
 
    @Bean(name = "secondSqlSessionTemplate")
    public SqlSessionTemplate secondSqlSessionTemplate(@Qualifier("secondSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

创建学生与老师实体类

Student实体类

package com.olive.entity.primary;
 
import java.io.Serializable;
import lombok.Data;
 
@Data
public class StudentDO implements Serializable{
 
    private Long id;
 
    private String name;
 
    private int sex;
    
    private String grade;
}

Teacher实体类

package com.olive.entity.second;
 
import java.io.Serializable;
import lombok.Data;
 
@Data
public class TeacherDO implements Serializable {
 
	private Long id;
 
	private String name;
 
	private int sex;
	
	private String office;
}

数据库持久类

StudentMapper类

package com.olive.mapper.primary;
 
import com.olive.entity.primary.StudentDO;
import org.apache.ibatis.annotations.Param;
 
 
public interface StudentMapper {
 
    int save(@Param("studentDO") StudentDO studentDO);
}

TeacherMapper类

package com.olive.mapper.second;
 
import com.olive.entity.second.TeacherDO;
import org.apache.ibatis.annotations.Param;
 
public interface TeacherMapper {
 
    int save(@Param("teacherDO") TeacherDO teacherDO);
}

Mybatis xml映射

StudentMapper.xml

mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.olive.mapper.primary.StudentMapper">
  <resultMap id="BaseResultMap" type="com.olive.entity.primary.StudentDO">
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="sex" jdbcType="INTEGER" property="sex" />
    <result column="grade" jdbcType="VARCHAR" property="grade" />
  resultMap>
 
  <insert id="save">
    INSERT INTO t_student (user_name, sex, grade) VALUES (#{studentDO.name}, #{studentDO.sex}, #{studentDO.grade});
  insert>
mapper>

TeacherMapper.xml

mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.olive.mapper.second.TeacherMapper">
  <resultMap id="BaseResultMap" type="com.olive.entity.second.TeacherDO">
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="sex" jdbcType="INTEGER" property="sex" />
    <result column="office" jdbcType="VARCHAR" property="office" />
  resultMap>
 
  <insert id="save">
    INSERT INTO t_teacher ( user_name, sex, office) VALUES (#{teacherDO.name}, #{teacherDO.sex}, #{teacherDO.office});
  insert>
mapper>

主要注意这两个xml文件需要放到不同的目录，如下图

创建springboot引导类

package com.olive;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class Application {
 
    public static void main(String[] args) {
        SpringApplication.run(Application.class);
    }
 
}

测试

package com.olive;
 
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
 
import com.olive.entity.primary.StudentDO;
import com.olive.entity.second.TeacherDO;
import com.olive.mapper.primary.StudentMapper;
import com.olive.mapper.second.TeacherMapper;
 
@SpringBootTest
public class MybatisTest {
 
	@Autowired
	StudentMapper studentMapper;
 
	@Autowired
	TeacherMapper teacherMapper;
 
	@Test
	public void userSave() {
		StudentDO studentDO = new StudentDO();
		studentDO.setName("BUG弄潮儿");
		studentDO.setSex(1);
		studentDO.setGrade("一年级");
		studentMapper.save(studentDO);
 
		TeacherDO teacherDO = new TeacherDO();
		teacherDO.setName("Java乐园");
		teacherDO.setSex(2);
		teacherDO.setOffice("语文");
		teacherMapper.save(teacherDO);
	}
}