文章目录

文章采用springboot+mysql+mybatis来配置两个数据库。其中数据库连接池采用的是springboot默认的 hikari ,如果想用其他的数据库连接池，请引入相关的依赖。

创建一个springboot项目，并在pom中引入相关的依赖

<parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.6.6</version>
      <relativePath/> <!-- lookup parent from repository -->
</parent>


<dependencies>

     
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
		//MySQL驱动
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
		//Mybatis依赖
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>
    </dependencies>

创建yml配置文件

因为我们需要配置两个数据源，而springboot默认配置DataSource时只能配置一个数据源，所以我们不能spring.dataSource这样进行配置了，我们要自定义一个配置，如下：

# 配置主库的相关连接信息
master:
 dataSource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/springcloud?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
    username: root
    password: 12345678

# 配置从库的相关配置
second:
  dataSource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://68.134.176.112:3306/zj?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
    username: root
    password: 12345678

上面的注释就表示在主库中查找springcould库中的相关信息，在从库中查找zj库中的相关信息，我这里将数据库装在了两台不同的机器上，其实也可以设置相同的ip地址，查询不同的库

创建主启动类

@SpringBootApplication
public class DatesourcetestApplication {

    public static void main(String[] args) {
        SpringApplication.run(DatesourcetestApplication.class, args);
    }

}

创建datasource配置类

配置两个不同的数据源
首先创建一个主用于配置master数据库的配置类。

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

    private static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";

    @Value("${master.dataSource.url}")
    private String url;

    @Value("${master.dataSource.username}")
    private String username;

    @Value("${master.dataSource.password}")
    private String password;

    @Value("${master.dataSource.driver-class-name}")
    private String driverClassName;


    @Primary
    @Bean("masterDataSource")
    public DataSource getMasterDataSource(){
        //创建一个数据源对象，springboot默认为Hikari数据源，我们也用该数据源
        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setDriverClassName(driverClassName);
        dataSource.setJdbcUrl(url);
        return dataSource;



    }

    @Bean("masterTransactionManager")
    @Primary
    public TransactionManager getMasterTransactionManager(){
        return new DataSourceTransactionManager
                ( getMasterDataSource());
    }

    @Bean("masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(masterDataSource);
        sqlSessionFactory.setMapperLocations(
                new PathMatchingResourcePatternResolver()
                .getResources(MAPPER_LOCATION)

        );
        return sqlSessionFactory.getObject();


    }
}

之后再配置second数据库的配置类

@Configuration
@MapperScan(basePackages = "com.zj.datesourcetest.second",sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {

    private static final String MAPPER_LOCATION = "classpath:mapper/second/*.xml";

    @Value("${second.dataSource.url}")
    private String url;

    @Value("${second.dataSource.username}")
    private String username;

    @Value("${second.dataSource.password}")
    private String password;

    @Value("${second.dataSource.driver-class-name}")
    private String driverClassName;



    @Bean("secondDataSource")
    public DataSource getSecondDataSource(){
        //创建一个数据源对象，springboot默认为Hikari数据源，我们也用该数据源
        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setDriverClassName(driverClassName);
        dataSource.setJdbcUrl(url);
        return dataSource;



    }

    @Bean("secondTransactionManager")
    public TransactionManager getSecondTransactionManager(){
        return new DataSourceTransactionManager
                ( getSecondDataSource());
    }

    @Bean("secondSqlSessionFactory")
    public SqlSessionFactory secondSqlSessionFactory(@Qualifier("secondDataSource") DataSource secondDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(secondDataSource);
        sqlSessionFactory.setMapperLocations(
                new PathMatchingResourcePatternResolver()
                .getResources(MAPPER_LOCATION)

        );
        return sqlSessionFactory.getObject();


    }
}

我们配置好了两个数据源的相关信息，就可以写mapper和xml了

配置mapper与xml

两个mapper：

@Mapper
public interface MasterMapper {

    String getSerialById(int id);
}

@Mapper
public interface SecondMapper {

    String getNameById(@Param("id") int id);
}

两个xml

<?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.zj.datesourcetest.master.MasterMapper">
    <select id="getSerialById" parameterType="int" resultType="String">
        select serial from payment where id=#{id}
    </select>

<!--    <insert id="savePayment" parameterType="com.zj.apiCommons.entity.Payment" useGeneratedKeys="true" keyProperty="id">-->
<!--        insert into payment(serial) values(#{serial})-->
<!--    </insert>-->
</mapper>

<?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.zj.datesourcetest.second.SecondMapper">
    <select id="getNameById" parameterType="int" resultType="String">
        select newname from jjj where id=#{id}
    </select>

<!--    <insert id="savePayment" parameterType="com.zj.apiCommons.entity.Payment" useGeneratedKeys="true" keyProperty="id">-->
<!--        insert into payment(serial) values(#{serial})-->
<!--    </insert>-->
</mapper>

基本的配置就已经完成了，不过先看看我的目录结构，以便于在创建项目的时候能有一个大概的了解。
在这里插入图片描述

测试

之后我们进行测试
测试的目的：
看看在同一个项目下是否可以对同一个项目处理两个数据库。
请自行在Test测试下测试下面两个方法

@SpringBootTest
class DatesourcetestApplicationTests {

    @Autowired
    private DataSource dataSource;

    @Autowired
    private MasterMapper masterMapper;

    @Autowired
    private SecondMapper secondMapper;

	//主库测试
    @Test
    public void MasterTest(){
        String serialById = masterMapper.getSerialById(1);
        System.out.println(serialById);
    }

	//从库配置
    @Test
    public void SecondTest(){
        String nameById = secondMapper.getNameById(23);
        System.out.println(nameById);
    }

}

测试后不报错就可以，至于数据库，请自行创建一些表自行测试

如果想要参考源代码，可以访问我的github地址进行拉取：

https://github.com/2290653824/springfamilybucket/tree/main/springfamilybucket/datesourcetest

# spring # mysql
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