springboot+mybatis多数据源最简解决方案

说起多数据源，一般都来解决那些问题呢，主从模式或者业务比较复杂需要连接不同的分库来支持业务。我们项目是后者的模式，网上找了很多，大都是根据jpa来做多数据源解决方案，要不就是老的spring多数据源解决方案，还有的是利用aop动态切换，感觉有点小复杂，其实我只是想找一个简单的多数据支持而已，折腾了两个小时整理出来，供大家参考。

废话不多说直接上代码吧

配置文件

pom包就不贴了比较简单该依赖的就依赖，主要是数据库这边的配置：

mybatis.config-locations=classpath:mybatis/mybatis-config.xml

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 = root

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 = root

一个test1库和一个test2库，其中test1位主库，在使用的过程中必须制定主库，不然会报错。

数据源配置

@Configuration

@MapperScan(basePackages =
"com.neo.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);

最关键的地方就是这块了，一层一层注入,先创建DataSource，在创建SqlSessionFactory在创建事务，最后包装到SqlSessionTemplate中。其中需要制定分库的mapper文件地址，以及分库到层代码。

@MapperScan(basePackages =
"com.neo.mapper.test1", sqlSessionTemplateRef  =
"test1SqlSessionTemplate")

这块的注解就是指明了扫描dao层，并且给dao层注入指定的SqlSessionTemplate。所有@Bean都需要按照命名指定正确。

dao层和xml层

dao层和xml需要按照库来分在不同的目录，比如：test1库dao层在com.neo.mapper.test1包下，test2库在com.neo.mapper.test1

public
interface
User1Mapper
{

    List<UserEntity>
getAll();

    UserEntity getOne(Long id);

    void
insert(UserEntity user);

    void
update(UserEntity user);

    void
delete(Long id);

xml层

<?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.neo.mapper.test1.User1Mapper" >


<resultMap
id="BaseResultMap" type="com.neo.entity.UserEntity" >


<id
column="id" property="id" jdbcType="BIGINT" />


<result
column="userName" property="userName" jdbcType="VARCHAR" />


<result
column="passWord" property="passWord" jdbcType="VARCHAR" />


<result
column="user_sex" property="userSex" javaType="com.neo.enums.UserSexEnum"/>


<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.Long" resultMap="BaseResultMap" >

        SELECT


<include
refid="Base_Column_List" />

       FROM users

       WHERE id = #{id}


</select>


<insert
id="insert" parameterType="com.neo.entity.UserEntity" >

       INSERT INTO

               users

               (userName,passWord,user_sex)

           VALUES

               (#{userName}, #{passWord}, #{userSex})


</insert>


<update
id="update" parameterType="com.neo.entity.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.Long" >

       DELETE FROM

                users

       WHERE

                id =#{id}


</delete>

</mapper>

测试

测试可以使用SpringBootTest,也可以放到Controller中，这里只贴Controller层的使用

@RestController

public
class
UserController
{

    @Autowired


private User1Mapper user1Mapper;

    @Autowired

    private User2Mapper user2Mapper;

    @RequestMapping("/getUsers")

    public List<UserEntity>
getUsers()
{

        List<UserEntity> users=user1Mapper.getAll();

        return users;

    @RequestMapping("/getUser")


public UserEntity getUser(Long 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="/delete/{id}")


public
void
delete(@PathVariable("id") Long id) {

        user1Mapper.delete(id);

最后源码地址在这里spring-boot-mybatis-mulidatasource