【Spring boot】双数据源/多数据源 spring boot+druid配置多数据源详细配置

1.pom.xml文件

<spring.boot.version>2.2.5.RELEASE</spring.boot.version>
<mysql-connector-java-version>6.0.6</mysql-connector-java-version>
<alibaba-druid-version>1.1.10</alibaba-druid-version>

<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.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
</dependencies>

2.启动类

// 这个就不需要在启动类加了，相比较单数据源  @MapperScan("com.swapping.dao.mapper.mysql")
@SpringBootApplication
@ComponentScan(basePackages = {"com.swapping.*"})
@Slf4j
public class SwappingApiApplication {

    public static void main(String[] args) {
        try {
            SpringApplication.run(SwappingApiApplication.class, args);
            System.out.println("SwappingApiApplication 启动成功......");
        } catch (Exception e) {
            log.error("SwappingApiApplication 启动失败", e);
        }
    }
}

3.yml配置文件

yml配置文件如下，双数据源如下，多数据源就往下加配置就行
注意：相比较单数据源，应该用jdbc-url做key，否则会有运行时异常 多数据源java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName.
${my_first_mysql.host} 或 ${my_sencond_tidb.host} 可以是配置文件取的配置，也可以像username一样直接写死，都可以

# 驱动配置信息
spring:
  datasource:
    my-first-mysql:
      #连接池的配置信息
      driver-class-name: com.mysql.cj.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
      druid:
        filters:
        max-active: 16
        initial-size: 2
        max-wait: 3000
        minIdle: 2
        time-between-eviction-runsMillis: 60000
        min-evictable-idle-timeMillis: 300000
        validation-query: SELECT 1
        test-while-idle: true
        test-on-borrow: false
        test-on-return: false
        pool-prepared-statements: false
        max-open-prepared-statements: -1
      jdbc-url: jdbc:mysql://${my_first_mysql.host}:${my_first_mysql.port}/my_first_mysql_dbName?characterEncoding=UTF-8&rewriteBatchedStatements=true&allowMultiQueries=true&serverTimezone=GMT%2B8&connectTimeout=2000&socketTimeout=150000
      username: XXX
      password: XXX
    my-sencond-tidb:
      #连接池的配置信息
      driver-class-name: com.mysql.cj.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
      druid:
        filters:
        max-active: 16
        initial-size: 2
        max-wait: 3000
        minIdle: 2
        time-between-eviction-runsMillis: 60000
        min-evictable-idle-timeMillis: 300000
        validation-query: SELECT 1
        test-while-idle: true
        test-on-borrow: false
        test-on-return: false
        pool-prepared-statements: false
        max-open-prepared-statements: -1
      jdbc-url: jdbc:mysql://${my_sencond_tidb.host}:${my_sencond_tidb.port}/my_sencond_mysql_dbName?characterEncoding=UTF-8&rewriteBatchedStatements=true&allowMultiQueries=true&serverTimezone=GMT%2B8&connectTimeout=2000&socketTimeout=150000
      username: XXX
      password: XXX

4.自定义DataSourceConfig

自定义DataSourceConfig，而不用Springboot自启动的DataSourceConfig。
两个数据源就定义两个，多个数据源就定义多个
如果重点2没有区分各数据源的包扫描路径，会有运行时异常：org.apache.ibatis.binding.BindingException: Invalid bound statement (not found)

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;


/**
 * 第一个数据源
 *
 * @author xudong.shen
 * @date 2022/04/16
 */
@Configuration
@MapperScan(basePackages = "com.swapping.dao.mapper.mysql", sqlSessionTemplateRef  = "sqlSessionTemplate")//重点1 指定包扫描，当前这个数据源对应的mapper.java文件放在哪个包下，这里路径就指定哪里
public class MyFirstDataSourceConfig {

    @Bean
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.my-first-mysql")//重点3 这里对应yml的当前数据源的前缀
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();

    }

    @Bean
    @Primary
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/mysql/*.xml"));//重点2 指定包扫描,当前这个数据源对应的mapper.xml文件在哪个resource下的包里，这里路径就指定哪里
        // bean.setPlugins(new Interceptor[] {xxx}); // 设置MyBatis插件
        return bean.getObject();
    }


    @Bean
    @Primary
    public DataSourceTransactionManager testTransactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    @Primary
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**
 * 第二个数据源
 *
 * @author xudong.shen
 * @date 2022/04/18
 */
@Configuration
@MapperScan(basePackages = "com.swapping.dao.mapper.tidb", sqlSessionTemplateRef  = "sqlSessionTemplateSecond")//重点1 指定包扫描，当前这个数据源对应的mapper.java文件放在哪个包下，这里路径就指定哪里
public class MySecondDataSourceConfig {


   
    @Bean(name = "dataSourceSecond")
    @ConfigurationProperties(prefix = "spring.datasource.my-sencond-tidb")//重点3 这里对应yml的当前数据源的前缀
    public DataSource testDataSource() {
        return DataSourceBuilder.create().build();

    }

    @Bean(name = "sqlSessionFactorySecond")
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("dataSourceSecond") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/tidb/*.xml"));//重点2 指定包扫描,当前这个数据源对应的mapper.xml文件在哪个resource下的包里，这里路径就指定哪里
        // bean.setPlugins(new Interceptor[] {xxx}); // 设置mybatis插件
        return bean.getObject();
    }

    @Bean(name = "transactionManagerSecond")
    public DataSourceTransactionManager testTransactionManager(@Qualifier("dataSourceSecond") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "sqlSessionTemplateSecond")
    public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("sqlSessionFactorySecond") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

5.Mapper.java 和 Mapper.xml的说明

到这里，多数据源的配置层面东西，就全部完成了。
后面的mapper.java  mapper.xml  就放在上面各自数据源的指定包路径下，即可。
后面Service调用Mapper的动作，就和单数据源 一样了。正常调用就行了。（当然，跨数据源了，事务肯定就行不通了！）