Springboot 整合Mybatis多数据源并动态切换

作者：hy_xiaobin 来源：https://juejin.im/post/5d8705e65188253f4b629f47

首先需要建立两个库进行测试，我这里使用的是master_test和slave_test两个库，两张库都有一张同样的表（偷懒），表名  t_user

字段名类型备注idint主键自增IDnamevarchar名称

表中分别添加两条不同数据，方便测试 主数据库记录name为xiaobin，从库为xiaoliu。 目录结构

开始使用Springboot 整合mybatis，首先引入pom文件。

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.4.RELEASE</version> </parent> <groupId>com.xiaobin</groupId> <artifactId>mysql_master_slave</artifactId> <version>1.0-SNAPSHOT</version> <properties> <java.version>1.8</java.version> <lombok.version>1.18.6</lombok.version> <mybatis.version>1.3.2</mybatis.version> <lombox.version>1.18.6</lombox.version> </properties> <dependencies> <!-- 添加web启动坐标 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- 添加lombok工具坐标 --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>${lombok.version}</version> </dependency> <!-- 添加springboot 测试坐标 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> </dependency> <!-- 添加lombox 测试坐标 --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>${lombox.version}</version> </dependency> <!-- 添加mybatis依赖坐标 --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>${mybatis.version}</version> </dependency> <!-- 添加mysql驱动器坐标 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!-- 添加druid数据源坐标 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <!-- 添加AOP坐标 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> </dependencies> </project>

动态数据源配置

这里使用的数据源为druid，实现数据源之间的切换用@DataSource自定义注解，配置Aop进行切换 application.yml 配置文件。

spring: datasource: type: com.alibaba.druid.pool.DruidDataSource druid: xiaobin-master: # 主数据源 driverClassName: com.mysql.jdbc.Driver username: root password: root url: jdbc:mysql://localhost:3306/master_test?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8 xiaobin-slave: # 从数据源 driverClassName: com.mysql.jdbc.Driver username: root password: root url: jdbc:mysql://localhost:3306/slave_test?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8 mybatis:  mapper-locations: classpath:mapper/*.xml

 多数据源配置类

@Configuration @Component public class DynamicDataSourceConfig { @Bean @ConfigurationProperties("spring.datasource.druid.xiaobin-master") public DataSource xiaobinMasterDataSource(){ return DruidDataSourceBuilder.create().build(); } @Bean @ConfigurationProperties("spring.datasource.druid.xiaobin-slave") public DataSource xiaobinSlaveDataSource(){ return DruidDataSourceBuilder.create().build(); } @Bean @Primary public DynamicDataSource dataSource(DataSource xiaobinMasterDataSource, DataSource xiaobinSlaveDataSource) { Map<Object, Object> targetDataSources = new HashMap<>(); targetDataSources.put("xiaobin-master",xiaobinMasterDataSource); targetDataSources.put("xiaobin-slave", xiaobinSlaveDataSource); return new DynamicDataSource(xiaobinMasterDataSource, targetDataSources);     } }

动态数据源切换类

public class DynamicDataSource  extends AbstractRoutingDataSource { private static final ThreadLocal<String> contextHolder = new ThreadLocal<>(); public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) { super.setDefaultTargetDataSource(defaultTargetDataSource); super.setTargetDataSources(targetDataSources); super.afterPropertiesSet(); } @Override protected Object determineCurrentLookupKey() { return getDataSource(); } public static void setDataSource(String dataSource) { contextHolder.set(dataSource); } public static String getDataSource() { return contextHolder.get(); } public static void clearDataSource() { contextHolder.remove(); } }

自定义@DataSource注解

在需要切换数据的Dao添加此注解

/**  * 备注：自定义数据源选择注解  **/ @Target(ElementType.METHOD) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface DataSource { String name() default ""; }

Aop切面类配置

@Aspect @Component public class DataSourceAspect { @Pointcut("@annotation(com.xiaobin.annotation.DataSource)") public void dataSourcePointCut() { } @Around("dataSourcePointCut()") public Object around(ProceedingJoinPoint point) throws Throwable { MethodSignature signature = (MethodSignature) point.getSignature(); Method method = signature.getMethod(); DataSource dataSource = method.getAnnotation(DataSource.class); if(dataSource == null){ DynamicDataSource.setDataSource("xiaobin-master"); }else { DynamicDataSource.setDataSource(dataSource.name()); } try { return point.proceed(); } finally { DynamicDataSource.clearDataSource(); } } }

启动配置注解信息，重要（不然运行会报错）

@SpringBootApplication(exclude= {DataSourceAutoConfiguration.class}) @MapperScan(basePackages = "com.xiaobin.mapper") @Import({DynamicDataSourceConfig.class}) public class StartApp { public static void main(String[] args) { SpringApplication.run(StartApp.class); } }

测试controller

@RestController @RequestMapping public class UserController { @Autowired private UserMapper userMapper; @GetMapping("/{name}/list") public List<TUser> list(@PathVariable("name")String name){ if(name.equals("master")){ return userMapper.queryAllWithMaster(); }else{ return userMapper.queryAllWithSlave(); } } }

效果图

更具路径传值，进行主从数据源切换

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