druiddatasource配置（druid pom配置）

         
  
    
    
     
     
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        org.springframework.boot 
                    
      
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        com.alibaba 
                    
      
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// 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);         }     } }

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:          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=       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:          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=       username: XXX       password: XXX

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);     } }

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！）