springboot初学---mybatis多数据源的解决方案

1.使用xml方式

<1>.application.properties配置文件

## mybatis使用xml的方式连接数据库
# mybatis.config-location=classpath:mybatis/mybatis-config.xml

# mybatis多数据原的配置
spring.datasource.test1.driverClassName =com.mysql.jdbc.Driver
spring.datasource.test1.url =jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8
spring.datasource.test1.username =root
spring.datasource.test1.password =

spring.datasource.test2.driverClassName =com.mysql.jdbc.Driver
spring.datasource.test2.url =jdbc:mysql://localhost:3306/test2?useUnicode=true&characterEncoding=utf-8
spring.datasource.test2.username =root
spring.datasource.test2.password =

说明:test1和test2位两个数据库,在使用过程中必须指明一个位主库,否则报错

<2>.数据源配置

package com.example.demo.datasource;

import javax.sql.DataSource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;

@Configuration

/**
* 指明了扫描dao层，并且给dao层注入指定的SqlSessionTemplate
*/

@MapperScan(basePackages = "com.example.demo.mapper.test1", sqlSessionTemplateRef = "test1SqlSessionTemplate")
public class DataSource1Config {

    @Bean(name = "test1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.test1")
    @Primary
    public DataSource testDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "test1SqlSessionFactory")
    @Primary
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(
                new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/mapper/test1/*.xml"));
        return bean.getObject();
    }

    @Bean(name = "test1TransactionManager")
    @Primary
    public DataSourceTransactionManager testTransactionManager(@Qualifier("test1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "test1SqlSessionTemplate")
    @Primary
    public SqlSessionTemplate testSqlSessionTemplate(
            @Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}

数据源test2和test1一样,只需要将@Primary注解去掉

<3>.mybatis-config.xml配置文件(配置头信息外空壳子就可以)

<4>.DAO层编写

public interface User1Mapper {
    List<UserEntity> getAll();

    UserEntity getOne(Integer id);

    void insert(UserEntity user);

    void update(UserEntity user);

    void delete(Integer id);
}

User2Mapper.java和这个一样即可

<5>.User1Mapper.xml文件配置

<?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.example.demo.mapper.test1.User1Mapper" >
    <resultMap id="BaseResultMap" type="com.example.demo.domain.UserEntity" >
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="userName" property="userName" jdbcType="VARCHAR" />
        <result column="passWord" property="passWord" jdbcType="VARCHAR" />
        <result column="user_sex" property="userSex" jdbcType="VARCHAR"/>
        <result column="nick_name" property="nickName" jdbcType="VARCHAR" />
    </resultMap>
    
    <sql id="Base_Column_List" >
        id, userName, passWord, user_sex, nick_name
    </sql>

    <select id="getAll" resultMap="BaseResultMap"  >
       SELECT 
       <include refid="Base_Column_List" />
       FROM users
    </select>

    <select id="getOne" parameterType="java.lang.Integer" resultMap="BaseResultMap" >
        SELECT 
       <include refid="Base_Column_List" />
       FROM users
       WHERE id = #{id}
    </select>

    <insert id="insert" parameterType="com.example.demo.domain.UserEntity" >
       INSERT INTO 
               users
               (userName,passWord,user_sex,nick_name) 
           VALUES
               (#{userName}, #{passWord}, #{userSex},#{nickName})
    </insert>
    
    <update id="update" parameterType="com.example.demo.domain.UserEntity" >
       UPDATE 
               users 
       SET 
           <if test="userName != null">userName = #{userName},</if>
           <if test="passWord != null">passWord = #{passWord},</if>
           nick_name = #{nickName}
       WHERE 
               id = #{id}
    </update>
    
    <delete id="delete" parameterType="java.lang.Integer" >
       DELETE FROM
                users 
       WHERE 
                id =#{id}
    </delete>
</mapper>

User2Mapper.xml配置一样即可

实体类省略

<6>.测试

@RestController
public class UserController {/**
     * 多数据库源的测试
     */
    /**** start */
    @Autowired
    private User1Mapper user1Mapper;

    @Autowired
    private User2Mapper user2Mapper;

    @RequestMapping("/getUsers1")
    public List<UserEntity> getUsers() {
        List<UserEntity> users = user1Mapper.getAll();
        return users;
    }

    @RequestMapping("/getUsers2")
    public List<UserEntity> getUsers2() {
        List<UserEntity> users = user2Mapper.getAll();
        return users;
    }


    @RequestMapping("/getUser1")
    public UserEntity getUser(Integer id) {
        UserEntity user = user1Mapper.getOne(id);
        return user;
    }
    @RequestMapping("/getUser2")
    public UserEntity getUser2(Integer id) {
        UserEntity user = user2Mapper.getOne(id);
        return user;
    }

    @RequestMapping("/add")
    public void save(UserEntity user) {
        user2Mapper.insert(user);
    }

    @RequestMapping(value = "update")
    public void update(UserEntity user) {
        user2Mapper.update(user);
    }

    @RequestMapping(value = "/deleteUser1/{id}")
    public void delete(@PathVariable("id") Integer id) {
        user1Mapper.delete(id);
    }

    @RequestMapping(value = "/deleteUser2/{id}")
    public void delete2(@PathVariable("id") Integer id) {
        user2Mapper.delete(id);
    }
    /****  end */
}