本篇文章详细介绍了基于阿里巴巴的Druid连接池的多数据源以及Spring 的自定义事务管理器实现方式。 技术栈： JDK：8 Spring Boot：2.5.5 Mybatis：2.2.0 Druid：1.1.10 (建议使用1.2.8,我受限于Nexus只能用1.1.10)

这两个数据源可以是异构数据库(未实测),注意调整相关配置

* date: 2021/11/26 15:20 * * @author Arvin Lee * @version 1.0 */ @Configuration @Slf4j public class DruidConfig { @Value("${spring.datasource.url:#{null}}") private String dbUrl; @Value("${spring.datasource.username: #{null}}") private String username; @Value("${spring.datasource.password:#{null}}") private String password; @Value("${spring.datasource.driverClassName:#{null}}") private String driverClassName; @Value("${spring.datasource2.url:#{null}}") private String dbUrl2; @Value("${spring.datasource2.username: #{null}}") private String username2; @Value("${spring.datasource2.password:#{null}}") private String password2; @Value("${spring.datasource2.driverClassName:#{null}}") private String driverClassName2; @Bean @Primary public DataSource dataSource() { return CommonFunctionInConfig.getDataSource(dbUrl, username, password, driverClassName, statFilter(), wallFilter()); } @Bean public DataSource dataSource2() { return CommonFunctionInConfig.getDataSource(dbUrl2, username2, password2, driverClassName2, statFilter(), wallFilter()); } @Bean public ServletRegistrationBean druidServlet() { ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*"); //控制台管理用户，加入下面2行 进入druid后台就需要登录 servletRegistrationBean.addInitParameter("loginUsername", "admin"); servletRegistrationBean.addInitParameter("loginPassword", "admin"); return servletRegistrationBean; } @Bean public FilterRegistrationBean filterRegistrationBean() { FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(); filterRegistrationBean.setFilter(new WebStatFilter()); filterRegistrationBean.addUrlPatterns("/*"); filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"); filterRegistrationBean.addInitParameter("profileEnable", "true"); return filterRegistrationBean; } @Bean public StatFilter statFilter() { StatFilter statFilter = new StatFilter(); //slowSqlMillis用来配置SQL慢的标准，执行时间超过slowSqlMillis的就是慢。 statFilter.setLogSlowSql(true); //SQL合并配置 statFilter.setMergeSql(true); //slowSqlMillis的缺省值为3000，也就是3秒。 statFilter.setSlowSqlMillis(1000); return statFilter; } @Bean public WallFilter wallFilter() { WallFilter wallFilter = new WallFilter(); //允许执行多条SQL WallConfig config = new WallConfig(); config.setMultiStatementAllow(true); wallFilter.setConfig(config); return wallFilter; } } 配置通用方法类 package com.xxx.config; import com.alibaba.druid.filter.Filter; import com.alibaba.druid.filter.stat.StatFilter; import com.alibaba.druid.pool.DruidDataSource; import com.alibaba.druid.wall.WallFilter; import java.util.ArrayList; import java.util.List; /** * Description: * 配置包下的通用方法 *

* date: 2021/11/29 15:06 * * @author Arvin Lee * @version 1.0 */ public class CommonFunctionInConfig { /** * getDataSource * 获取数据源 * * @param dbUrl 数据库连接地址 * @param username 用户名 * @param password 密码 * @param driverClassName 驱动名 * @param statFilter - * @param wallFilter - * @return com.alibaba.druid.pool.DruidDataSource * @author Arvin Lee * @date 2021/12/7 9:28 **/ protected static DruidDataSource getDataSource(String dbUrl, String username, String password, String driverClassName, StatFilter statFilter, WallFilter wallFilter) { DruidDataSource datasource = new DruidDataSource(); datasource.setUrl(dbUrl); datasource.setUsername(username); datasource.setPassword(password); datasource.setDriverClassName(driverClassName); List filters = new ArrayList(); filters.add(statFilter); filters.add(wallFilter); datasource.setProxyFilters(filters); return datasource; } }

连接池其他配置参数可以在这里统一调整

* date: 2021/11/26 15:39 * * @author Arvin Lee * @version 1.0 */ @Configuration @MapperScan(basePackages = "com.xxx.dao.datasource1", markerInterface = BaseMapper.class, sqlSessionFactoryRef = "sqlSessionFactory") public class DataSourceConfig { @Resource @Qualifier("dataSource") private DataSource ds; @Bean public SqlSessionFactory sqlSessionFactory() throws Exception { SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean(); factoryBean.setDataSource(ds); //指定mapper xml目录 ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); factoryBean.setMapperLocations(resolver.getResources("classpath:mapper/datasource1/*.xml")); return factoryBean.getObject(); } @Bean public SqlSessionTemplate sqlSessionTemplate() throws Exception { // 使用上面配置的Factory return new SqlSessionTemplate(sqlSessionFactory()); } /** * masterTransactionManager * 关于事务管理器，不管是JPA还是JDBC等都实现自接口 PlatformTransactionManager * 如果你添加的是 spring-boot-starter-jdbc 依赖，框架会默认注入 DataSourceTransactionManager 实例。 * 在Spring容器中，我们手工注解@Bean 将被优先加载，框架不会重新实例化其他的 PlatformTransactionManager 实现类。 * * @return org.springframework.jdbc.datasource.DataSourceTransactionManager * @author Arvin Lee * @date 2021/11/26 15:42 **/ @Bean(name = "transactionManager") @Primary public DataSourceTransactionManager masterTransactionManager() { //MyBatis自动参与到spring事务管理中，无需额外配置，只要org.mybatis.spring.SqlSessionFactoryBean引用的数据源 // 与DataSourceTransactionManager引用的数据源一致即可，否则事务管理会不起作用。 return new DataSourceTransactionManager(ds); } } 此处需要注意一下，代码经过脱敏，所以MapperScan 注解的 basePackages 路径com.xxx.dao.datasource1 大意如下 –com.xxx ------dao (存放dao层接口) ----------datasource1(与第一个数据源映射的dao) ----------datasource2(与第二个数据源映射的dao)markerInterface 对应的BaseMapper.class是我自定义的Mybatis的BaseMapper，如果没有可以不写。sqlSessionFactoryRef 参考的sql会话工厂，这个与返回SqlSessionFactory的方法的方法名对应@Qualifier(“dataSource”) 这是给DataSource起别名，因为是多数据源，命名没有特殊要求。classpath:mapper/datasource1/*.xml 这个是mapper.xml映射路径，路径格式参考dao 示例： –reosurce ------mapper ----------datasource1 ----------datasource2 第二个数据源(datasource2)配置类 package com.xxx.config; import com.xxx.common.BaseMapper; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.SqlSessionTemplate; import org.springframework.beans.factory.annotation.Qualifier; 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.core.io.support.ResourcePatternResolver; import org.springframework.jdbc.datasource.DataSourceTransactionManager; import tk.mybatis.spring.annotation.MapperScan; import javax.annotation.Resource; import javax.sql.DataSource; /** * Description: * mybatis数据源2配置 *

* date: 2021/11/26 16:02 * * @author Arvin Lee * @version 1.0 */ @Configuration @MapperScan(basePackages = "com.xxx.dao.datasource2", markerInterface = BaseMapper.class, sqlSessionFactoryRef = "sqlSessionFactory2") public class DataSource2Config { @Resource @Qualifier("dataSource2") private DataSource ds; @Bean public SqlSessionFactory sqlSessionFactory2() throws Exception { SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean(); factoryBean.setDataSource(ds); //指定mapper xml目录 ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); factoryBean.setMapperLocations(resolver.getResources("classpath:mapper/datasource2/*.xml")); return factoryBean.getObject(); } @Bean public SqlSessionTemplate sqlSessionTemplate2() throws Exception { // 使用上面配置的Factory return new SqlSessionTemplate(sqlSessionFactory2()); } /** * masterTransactionManager * 关于事务管理器，不管是JPA还是JDBC等都实现自接口 PlatformTransactionManager * 如果你添加的是 spring-boot-starter-jdbc 依赖，框架会默认注入 DataSourceTransactionManager 实例。 * 在Spring容器中，我们手工注解@Bean 将被优先加载，框架不会重新实例化其他的 PlatformTransactionManager 实现类。 * * @return org.springframework.jdbc.datasource.DataSourceTransactionManager * @author Arvin Lee * @date 2021/11/26 15:42 **/ @Bean(name = "transactionManager2") @Primary public DataSourceTransactionManager masterTransactionManager() { //MyBatis自动参与到spring事务管理中，无需额外配置，只要org.mybatis.spring.SqlSessionFactoryBean引用的数据源 // 与DataSourceTransactionManager引用的数据源一致即可，否则事务管理会不起作用。 return new DataSourceTransactionManager(ds); } } 格式与第一个一致，只不过dao、mapper.xml、datasource、SQLSessionFactory不同，需要加个2如果3个数据源，以此类推，再加个DataSourceConfig 同时也要修改DruidConfig 自定义事务管理器通用方法类 package com.xxx.interceptor; import org.springframework.transaction.TransactionDefinition; import org.springframework.transaction.TransactionManager; import org.springframework.transaction.interceptor.*; import java.util.Collections; import java.util.HashMap; import java.util.Map; /** * Description: *

* date: 2021/11/29 10:11 * * @author Arvin Lee * @version 1.0 */ public class OtherFunction { private static final int TX_METHOD_TIMEOUT = 50000; protected static TransactionInterceptor getInterceptor(TransactionManager transactionManager) { NameMatchTransactionAttributeSource source = new NameMatchTransactionAttributeSource(); /*只读事务，不做更新操作*/ RuleBasedTransactionAttribute readOnlyTx = new RuleBasedTransactionAttribute(); readOnlyTx.setReadOnly(true); readOnlyTx.setPropagationBehavior(TransactionDefinition.PROPAGATION_NOT_SUPPORTED); /*当前存在事务就使用当前事务，当前不存在事务就创建一个新的事务*/ RuleBasedTransactionAttribute requiredTx = new RuleBasedTransactionAttribute(); requiredTx.setRollbackRules(Collections.singletonList(new RollbackRuleAttribute(Exception.class))); requiredTx.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED); requiredTx.setTimeout(TX_METHOD_TIMEOUT); Map txMap = new HashMap(8); txMap.put("add*", requiredTx); txMap.put("save*", requiredTx); txMap.put("insert*", requiredTx); txMap.put("update*", requiredTx); txMap.put("delete*", requiredTx); txMap.put("get*", readOnlyTx); txMap.put("select*", readOnlyTx); txMap.put("query*", readOnlyTx); source.setNameMap(txMap); return new TransactionInterceptor(transactionManager, source); } }

这个是下面事务管理器的基础

* date: 2021/11/26 15:44 */ @Aspect @Configuration public class TxAdviceInterceptor { /** * 单位秒 */ private static final String AOP_POINTCUT_EXPRESSION = "execution (* com.xxx.service.datasource1.*.*(..))"; @Resource @Qualifier("transactionManager") private TransactionManager transactionManager; @Bean public TransactionInterceptor txAdvice() { return OtherFunction.getInterceptor(transactionManager); } @Bean public Advisor txAdviceAdvisor() { AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut(); pointcut.setExpression(AOP_POINTCUT_EXPRESSION); return new DefaultPointcutAdvisor(pointcut, txAdvice()); } }

service映射路径规则与dao一致，不做赘述

* date: 2021/11/26 16:05 * * @author Arvin Lee * @version 1.0 */ @Aspect @Configuration public class TxAdvice2Interceptor { /** * 单位秒 */ private static final String AOP_POINTCUT_EXPRESSION = "execution (* com.xxx.service.datasource2.*.*(..))"; @Resource @Qualifier("transactionManager2") private TransactionManager transactionManager; @Bean public TransactionInterceptor txAdvice2() { return OtherFunction.getInterceptor(transactionManager); } @Bean public Advisor txAdviceAdvisor2() { AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut(); pointcut.setExpression(AOP_POINTCUT_EXPRESSION); return new DefaultPointcutAdvisor(pointcut, txAdvice2()); } }

同上