原文出处：
纯洁的微笑
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。
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：
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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
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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
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@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);
}
}
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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
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@MapperScan
(basePackages =
"com.neo.mapper.test1"
, sqlSessionTemplateRef =
"test1SqlSessionTemplate"
)
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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
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public
interface
User1Mapper {
List<UserEntity> getAll();
UserEntity getOne(Long id);
void
insert(UserEntity user);
void
update(UserEntity user);
void
delete(Long id);
}
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xml层
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<?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>
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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
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@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);
}
}
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