springboot之集成mybatis之多數據源

多數據源，通常用來解決主從模式或者業務比較複雜須要鏈接不一樣的分庫的情景。

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

一個test1庫和一個test2庫，其中test1位主庫，在使用的過程當中必須指定主庫，否則會報錯。

數據源配置

@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，而後建立SqlSessionFactory，再建立事務，最後封裝到SqlSessionTemplate中。其中須要指定分庫的mapper文件地址，以及分庫dao層代碼

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

這塊的註解就是指明瞭掃描dao層，而且給dao層注入指定的SqlSessionTemplate。全部@Bean都須要按照命名指定。

dao層和xml層

dao層和xml須要按照庫來分在不一樣的目錄

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

	void insert(UserEntity user);

	void update(UserEntity user);

	void delete(Long id);

}

xml層

<?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>

測試

測試能夠使用SpringBootTest,也能夠放到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);
    }
    
}