springboot--springboot+mybatis多資料來源最簡解決方案，

springboot--springboot+mybatis多資料來源最簡解決方案，

說起多資料來源，一般都來解決那些問題呢，主從模式或者業務比較複雜需要串連不同的分庫來支援業務。我們項目是後者的模式，網上找了很多，大都是根據jpa來做多資料來源解決方案，要不就是老的spring多資料來源解決方案，還有的是利用aop動態切換，感覺有點小複雜，其實我只是想找一個簡單的多資料支援而已，折騰了兩個小時整理出來，供大家參考。

廢話不多說直接上代碼吧
設定檔
pom包就不貼了比較簡單該依賴的就依賴，主要是資料庫這邊的配置：

mybatis.config-locations=classpath:mybatis/mybatis-config.xmlspring.datasource.test1.driverClassName = com.mysql.jdbc.Driverspring.datasource.test1.url = jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf-8spring.datasource.test1.username = rootspring.datasource.test1.password = rootspring.datasource.test2.driverClassName = com.mysql.jdbc.Driverspring.datasource.test2.url = jdbc:mysql://localhost:3306/test2?useUnicode=true&characterEncoding=utf-8spring.datasource.test2.username = rootspring.datasource.test2.password = root

一個test1庫和一個test2庫，其中test1位主庫，在使用的過程中必須制定主庫，不然會報錯。
資料來源配置

@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);     }}

最關鍵的地方就是這塊了，一層一層注入,先建立DataSource，在建立SqlSessionFactory在建立事務，最後封裝到SqlSessionTemplate中。其中需要制定分庫的mapper檔案地址，以及分庫到層代碼

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

這塊的註解就是指明了掃描dao層，並且給dao層注入指定的SqlSessionTemplate。所有@Bean都需要按照命名指定正確。
dao層和xml層
dao層和xml需要按照庫來分在不同的目錄，比如：test1庫dao層在com.neo.mapper.test1包下，test2庫在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
測試可以使用SpringBootTest,也可以放到Controller中，這裡只貼Controller層的使用

@RestControllerpublic 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);    }}

最後源碼地址在這裡：https://github.com/ityouknow/spring-boot-starter

文章來源：http://mp.weixin.qq.com/s/ESI8K3voQKyl6Pj7zbK6qw

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