最近由于項目中需要同時連接兩個數(shù)據(jù)庫，所以需要配置多個數(shù)據(jù)源，由于springboot 默認(rèn)幫我們做了很多自動配置，所以在配置的時候就遇到了問，稍后我們會討論這個問題。

項目依賴

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.3.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <version>1.5.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>6.0.5</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.12</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
            <version>1.5.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.29</version>
        </dependency>

數(shù)據(jù)庫不同源配置文件

master連接的是test庫，slave連接的是haozi，這里的命名并沒有主從關(guān)系，只是為了區(qū)分

datasource.master.url=jdbc:mysql://127.0.0.1:3306/test
datasource.master.driverClassName=com.mysql.jdbc.Driver
datasource.master.username=root
datasource.master.password=


datasource.slave.url=jdbc:mysql://127.0.0.1:3306/haozi
datasource.slave.driverClassName=com.mysql.jdbc.Driver
datasource.slave.username=root
datasource.slave.password=

Master Mybatis配置

@Configuration
@MapperScan(basePackages = "com.example.mapper.master",sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {

    @Bean(name = "masterDataSource")
    @ConfigurationProperties("datasource.master")
    public DataSource masterDataSource(){
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "masterSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
        .getResources("classpath*:mapper/master/*.xml"));
        return sessionFactoryBean.getObject();
    }

}

Slave Mybatis配置

@Configuration
@MapperScan(basePackages = "com.example.mapper.slave",sqlSessionFactoryRef = "slaveSqlSessionFactory")
public class SlaveSourceConfig {
    @Bean(name = "slaveDataSource")
    @ConfigurationProperties("datasource.slave")
    public DataSource slaveDataSource(){
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "slaveSqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("slaveDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/slave/*.xml"));
        return sessionFactoryBean.getObject();
    }
}

結(jié)構(gòu)圖及對應(yīng)關(guān)系分析

structure1.png

這里的mapper目錄下的master和slave主要存放的是mapper接口，被上面的DataSourceConfig上的@MapperScan注解所燒面，這里面我把master和slave的mapper接口放在不同的子目錄下了。

structure1.png

這里分別放的是和上面mapper接口對應(yīng)的.xml文件，被上面的配置來掃描，然后通過setMapperLocations注冊到SqlSessionFactory中。

可能遇到的問題

• mybatis required a single bean, but 2 were found
  這是因我們這里配置了兩個數(shù)據(jù)源，springboot會自動的注入，但是注入的時候發(fā)現(xiàn)有兩個，所以不知道選擇哪一個了，因為我們要關(guān)閉springboot關(guān)于mybatis的一些自動注入，在@SpringBootApplication注解下面，加入一個@EnableAutoConfiguration(exclude=""），具體如下：

@SpringBootApplication
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class,DataSourceTransactionManagerAutoConfiguration.class, MybatisAutoConfiguration.class})

第一個是數(shù)據(jù)源，第二個是數(shù)據(jù)源的事務(wù)管理器，第三個是和SessionFactory相關(guān)的。