springboot之集成mybatis之多数据源

多数据源，通常用来解决主从模式或者业务比较复杂须要链接不一样的分库的情景。

配置文件

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，在使用的过程当中必须指定主库，否则会报错。

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);
    }

}

首先建立DataSource，而后建立SqlSessionFactory，再建立事务，最后封装到SqlSessionTemplate中。其中须要指定分库的mapper文件地址，以及分库dao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，而且给dao层注入指定的SqlSessionTemplate。全部@Bean都须要按照命名指定。

dao层和xml层

dao层和xml须要按照库来分在不一样的目录

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

测试能够使用SpringBootTest,也能够放到Controller中

@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);
    }
    
}