一、前言
本教程主要内容
- 使用Spring Boot+MyBatis访问多个数据源
 
本教程开发环境
1、操作系统: Windows 10 X64
2、Java SDK: jdk-8u141
3、Maven:3.5
4、IDE:IntelliJ IDEA 2017
5、Spring Boot:1.5.6
本项目构建基于:https://ken.io/note/springboot-course-basic-curd-xml
二、多数据源配置
1、创建数据库&表
- 创建数据库test
 
CREATE DATABASE test;
- 创建表:note
 
DROP TABLE IF EXISTS `note`;
CREATE TABLE `note` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) DEFAULT NULL,
  `body` longtext,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
2、修改配置文件增加数据源
修改数据库连接配置(application.yml),将之前的spring.datasource更换为自定义的courseDataSource、testDataSource
#数据库连接配置
courseDataSource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/course?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
testDataSource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
3、调整数据源对应实体
1、在io.ken.springboot.course.model下新建两个package:course、test
2、将User.java移动到io.ken.springboot.course.model.course
3、在io.ken.springboot.course.model.test下新建Note.java
package io.ken.springboot.course.model.test;
public class Note {
    private int id;
    private String title;
    private String body;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getBody() {
        return body;
    }
    public void setBody(String body) {
        this.body = body;
    }
}
4、配置数据源对应Configuration
1、在io.ken.springboot.course.dao下新建两个package:course、test
2、将UserMapper.java移动到io.ken.springboot.course.dao.course并去掉@Mapper注解
3、在io.ken.springboot.course.dao.test下新建NoteMapper.java
package io.ken.springboot.course.dao.test;
import io.ken.springboot.course.model.test.Note;
import java.util.List;
public interface NoteMapper {
    List<Note> queryAll();
}
5、调整MyBatis Mappere配置
1、在/resources/conf/mybatis/mapper下新建两个文件夹:course、test
2、将UserMapper.xml移动到/resources/conf/mybatis/mapper/course
3、在/resources/conf/mybatis/mapper/test下新建NoteMapper.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="io.ken.springboot.course.dao.test.NoteMapper">
    <select id="queryAll" resultType="io.ken.springboot.course.model.test.Note">
        SELECT * FROM note
    </select>
</mapper>
6、配置数据源对应Configuration
1、在io.ken.springboot.course下新建package:config
2、在io.ken.springboot.course.config下创建CourseDbConfig.java
package io.ken.springboot.course.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.autoconfigure.jdbc.DataSourceBuilder;
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 javax.sql.DataSource;
@Configuration
@MapperScan(basePackages = "io.ken.springboot.course.dao.course", sqlSessionFactoryRef = "courseSqlSessionFactory")
public class CourseDbConfig {
    @Bean(name = "courseDataSource")
    @ConfigurationProperties(prefix = "courseDataSource")
    @Primary
    public DataSource courseDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "courseSqlSessionFactory")
    @Primary
    public SqlSessionFactory courseSqlSessionFactory(@Qualifier("courseDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:conf/mybatis/mapper/course/*.xml"));
        return bean.getObject();
    }
}
3、在io.ken.springboot.course.config下创建TestDbConfig.java
package io.ken.springboot.course.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.autoconfigure.jdbc.DataSourceBuilder;
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 javax.sql.DataSource;
@Configuration
@MapperScan(basePackages = "io.ken.springboot.course.dao.test", sqlSessionFactoryRef = "testSqlSessionFactory")
public class TestDbConfig {
    @Bean(name = "testDataSource")
    @ConfigurationProperties(prefix = "testDataSource")
    public DataSource testDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "testSqlSessionFactory")
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("testDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:conf/mybatis/mapper/test/*.xml"));
        return bean.getObject();
    }
}
7、创建NoteController并提供API
package io.ken.springboot.course.controller;
import io.ken.springboot.course.dao.test.NoteMapper;
import io.ken.springboot.course.model.test.Note;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.List;
@Controller
@RequestMapping("/note")
public class NoteController {
    @Autowired
    NoteMapper noteMapper;
    @RequestMapping("/queryall")
    @ResponseBody
    List<Note> queryAll() {
        return noteMapper.queryAll();
    }
}
8、API测试
| API | 示例 | 
|---|---|
| 添加用户 | /user/add?name=tom&age=1&hobby=football | 
| 更新用户 | /user/updatebyid?name=ken&age=18&hobby=coding&id=1 | 
| 查询指定用户 | /user/querybyid?id=1 | 
| 查询所有用户 | /user/queryall | 
| 删除指定用户 | /user/delbyid?id=2 | 
| 查询所有日志 | /note/queryall | 
三、备注
- 本文代码示例
 
https://github.com/ken-io/springboot-course/tree/master/chapter-02-04