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SpringBoot整合Mybatis-Plus+Druid实现多数据源

news 来源：原创 2025/9/14 16:56:26

概述

Spring Boot：
Spring Boot是一个基于Spring框架的开源Java开发框架，旨在简化Spring应用程序的开发、配置和部署。它提供了一种快速、敏捷的方式来构建独立的、生产级别的Spring应用程序，同时还提供了许多开箱即用的功能和工具，如自动配置、内嵌式Web容器、健康检查、监控和管理等。

Mybatis-Plus：
Mybatis-Plus是一个基于Mybatis的增强工具，它在Mybatis的基础上扩展了许多实用的功能，可以帮助开发人员更加高效地完成数据库操作，提高开发效率和代码质量。

Druid：
Druid是一个高性能的数据库连接池，它可以与各种关系型数据库进行集成，如MySQL、Oracle、PostgreSQL等。Druid提供了可扩展、高可用、高性能的数据库连接管理功能，可以帮助开发人员更加高效地完成数据库操作。

有了基本的理解接下来我们用这些组合实现多数据源功能

🍹1. pom.xml 添加依赖

加入一些必要的pom依赖：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><!--spring-boot-web--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--mybatis-plus--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.1.2</version></dependency><!-- druid--><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.16</version></dependency><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><!--   mysql     --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version></dependency>

🛑2. application.yml

spring:datasource:druid:initial-size: 5min-idle: 5max-active: 5db1:url: jdbc:mysql://localhost:6030/demo?useUnicode=true&characterEncoding=utf-8&useSSL=false&allowPublicKeyRetrieval=true&nullCatalogMeansCurrent=true&useInformationSchema=trueusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driverdb2:url: jdbc:mysql://localhost:6030/demo1?useUnicode=true&characterEncoding=utf-8&useSSL=false&allowPublicKeyRetrieval=true&nullCatalogMeansCurrent=true&useInformationSchema=trueusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver
mybatis-plus:configuration:map-underscore-to-camel-case: false

⏳ 3. 排除默认加载

在项目启动类中排除druid属性默认加载（也可以直接在配置中加载我的项目配置没有成功就直接用这种方式了）
不加这个多数据源可能无法都加载出来

@SpringBootApplication(exclude = DruidDataSourceAutoConfigure.class)

🛎 4. Mybatis-Plus 配置

添加mybatisplus的多数据源配置

@Configuration
public class MybatisPlusConfig {/** mybatis 3.4.1 pagination config start ***/@Beanpublic PaginationInterceptor paginationInterceptor() {//        return new PaginationInterceptor();PaginationInterceptor paginationInterceptor = new PaginationInterceptor();paginationInterceptor.setDialectType("postgresql");return paginationInterceptor;}/*** SQL执行效率插件(优化sql的执行效率 不需要可以不加)* */@Bean@Profile({"dev","qa"})// 设置 dev test 环境开启public PerformanceInterceptor performanceInterceptor() {PerformanceInterceptor performanceInterceptor = new PerformanceInterceptor();performanceInterceptor.setMaxTime(1000);performanceInterceptor.setFormat(true);return performanceInterceptor;}/*** 多数据源的创建 有几个就写几个 */@Bean(name = "db1")@ConfigurationProperties(prefix = "spring.datasource.druid.db1" )public DataSource db1() {return DruidDataSourceBuilder.create().build();}@Bean(name = "db2")@ConfigurationProperties(prefix = "spring.datasource.druid.db2" )public DataSource db2() {return DruidDataSourceBuilder.create().build();}/*** 动态数据源配置* @return*/@Bean@Primarypublic DataSource multipleDataSource(@Qualifier("db1") DataSource db1, @Qualifier("db2") DataSource db2) {DynamicDataSource dynamicDataSource = new DynamicDataSource();Map< Object, Object > targetDataSources = new HashMap<>();targetDataSources.put(DataSourceEnum.DB1.getValue(), db1);targetDataSources.put(DataSourceEnum.DB2.getValue(), db2);//添加数据源dynamicDataSource.setTargetDataSources(targetDataSources);//设置默认数据源dynamicDataSource.setDefaultTargetDataSource(db1);return dynamicDataSource;}@Bean("sqlSessionFactory")public SqlSessionFactory sqlSessionFactory() throws Exception {MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();sqlSessionFactory.setDataSource(multipleDataSource(db1(),db2()));//sqlSessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:/mapper/*/*Mapper.xml"));MybatisConfiguration configuration = new MybatisConfiguration();//configuration.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);configuration.setJdbcTypeForNull(JdbcType.NULL);configuration.setMapUnderscoreToCamelCase(true);configuration.setCacheEnabled(false);sqlSessionFactory.setConfiguration(configuration);sqlSessionFactory.setPlugins(new Interceptor[]{//PerformanceInterceptor(),OptimisticLockerInterceptor()paginationInterceptor()//添加分页功能});//sqlSessionFactory.setGlobalConfig(globalConfiguration());return sqlSessionFactory.getObject();}
}

🪐5. 多数据源实例：

🔒 5.1 DataSourceEnum

public enum DataSourceEnum {DB1("db1"),DB2("db2");private String value;DataSourceEnum(String value){this.value=value;}public String getValue() {return value;}
}

🔓 5.2 DataSource

自定义多数据源切换：

/** * 自定义多数据源切换* @author zzh* @date 2023/4/28 15:19:21*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
public @interface DataSource {DataSourceEnum value() default DataSourceEnum.DB1;
}

🔏 5.3 DataSourceAspect

切面处理类：

@Aspect
@Order(1)
@Component
public class DataSourceAspect {@Pointcut("@annotation(com.taosdata.example.mybatisplusdemo.datasource.annotation.DataSource)"+ "|| @within(com.taosdata.example.mybatisplusdemo.datasource.annotation.DataSource)")public void dsPc() {}@Before("dsPc()  && @annotation(dataSource)")public void doBefore(DataSource dataSource)  {DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().getValue());}@After("dsPc()")public void doAfter() {DynamicDataSourceContextHolder.clearDataSourceType();}}

🔐 5.4 DruidConfiguration

driud配置类配置启动视图和过滤规则

@Configuration
public class DruidConfiguration {@Beanpublic ServletRegistrationBean startViewServlet(){ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");// IP白名单servletRegistrationBean.addInitParameter("allow","127.0.0.1");// IP黑名单(共同存在时，deny优先于allow)servletRegistrationBean.addInitParameter("deny","127.0.0.1");//控制台管理用户servletRegistrationBean.addInitParameter("loginUsername","admin");servletRegistrationBean.addInitParameter("loginPassword","123456");//是否能够重置数据servletRegistrationBean.addInitParameter("resetEnable","false");return servletRegistrationBean;}@Beanpublic FilterRegistrationBean statFilter(){FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());//添加过滤规则filterRegistrationBean.addUrlPatterns("/*");//忽略过滤的格式filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");return filterRegistrationBean;}
}

🔏 5.5 DynamicDataSource

动态数据源决策

public class DynamicDataSource extends AbstractRoutingDataSource {/*** @description:  动态数据源决策* @return*/@Overrideprotected Object determineCurrentLookupKey() {String dataSourceType = DynamicDataSourceContextHolder.getDataSourceType();return dataSourceType;}
}

🔓 5.6 DynamicDataSourceContextHolder

多数据源上下文

public class DynamicDataSourceContextHolder {public static final Logger log = LoggerFactory.getLogger(DynamicDataSourceContextHolder.class);/*** 使用ThreadLocal维护变量，ThreadLocal为每个使用该变量的线程提供独立的变量副本，* 所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。*/private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();/*** 设置数据源的变量*/public static void setDataSourceType(String dsType) {log.info("切换到{}数据源", dsType);CONTEXT_HOLDER.set(dsType);}/*** 获得数据源的变量*/public static String getDataSourceType() {return CONTEXT_HOLDER.get();}/*** 清空数据源变量*/public static void clearDataSourceType() {CONTEXT_HOLDER.remove();}
}

概述