springboot+mybatis实现动态切换数据源

目前有个需求，需要使用不同的数据源，例如某业务要用A数据源，另一个业务要用B数据源。

如何在spring框架中解决多数据源的问题

使用springboot 整合多数据源 遇到的坑

1、添加依赖

<!-- 阿里的druid 依赖log4j -->
<dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.0</version>
</dependency>
<dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.1</version>
</dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.2</version>
</dependency><!-- 引入mybatis-spring -->
<dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.3.1</version>
</dependency>

 

2、application.properties配置文件

#主数据库
master:db:driverClassName: com.mysql.jdbc.Driverurl: jdbc:mysql://47.111.22.159:3306/xinyar_erp_uat?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=falseusername: erp_testpassword: erp_test@abc#从数据库    
slave:db:driverClassName: com.mysql.jdbc.Driverurl: jdbc:mysql://47.111.22.159:3306/erp-test?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=falseusername: erp_testpassword: erp_test@abcmybatis:mapper-locations: classpath*:com/xinyartech/erp/*/xml/*/*.xmltype-aliases-package: com.xinyartech.erp.*.model,com.xinyartech.erp.*.voconfiguration: map-underscore-to-camel-case: true

 

java的import，3、禁用springboot默认加载数据源配置

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class Application {public static void main(String[] args) throws Exception {SpringApplication.run(Application.class, args);}
}

 

4、主数据源配置类

import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Configuration;import lombok.Data;
import org.springframework.beans.factory.annotation.Value;/*** 主数据源* * @author Lynch**/
@Configuration
@ConfigurationProperties(prefix = "master.db")
@Data
public class MasterDataSourceConfig {@Value("${master.db.url}")private String url;@Value("${master.db.username}")private String username;@Value("${master.db.password}")private String password;@Value("${master.db.driverClassName}")private String driverClassName;
}

 

5、从数据源配置类

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;import lombok.Data;/*** 从数据源* * @author Lynch**/
@Configuration
@ConfigurationProperties(prefix = "slave.db")
@Data
public class SlaveDataSourceConfig {@Value("${slave.db.url}")private String url;@Value("${slave.db.username}")private String username;@Value("${slave.db.password}")private String password;@Value("${slave.db.driverClassName}")private String driverClassName;
}

springboot不配置数据源。 

6、数据源配置类

import java.util.HashMap;
import java.util.Map;import javax.annotation.Resource;
import javax.sql.DataSource;import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.DependsOn;
import org.springframework.context.annotation.Primary;import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;/*** 数据源配置类** @author Lynch*/
@Configuration
public class DataSourceComponent {@Resourceprivate MasterDataSourceConfig masterDataSourceConfig;@Resourceprivate SlaveDataSourceConfig slaveDataSourceConfig;@Bean(name = "master")public DataSource masterDataSource() {DruidDataSource dataSource = new DruidDataSource();dataSource.setUrl(masterDataSourceConfig.getUrl());dataSource.setUsername(masterDataSourceConfig.getUsername());dataSource.setPassword(masterDataSourceConfig.getPassword());dataSource.setDriverClassName(masterDataSourceConfig.getDriverClassName());return dataSource;}@Bean(name = "slave")public DataSource slaveDataSource() {DruidDataSource dataSource = new DruidDataSource();dataSource.setUrl(slaveDataSourceConfig.getUrl());dataSource.setUsername(slaveDataSourceConfig.getUsername());dataSource.setPassword(slaveDataSourceConfig.getPassword());dataSource.setDriverClassName(slaveDataSourceConfig.getDriverClassName());return dataSource;}@Primary//不加这个会报错。@DependsOn({ "master", "slave"}) //解决数据库循环依赖问题@Bean(name = "multiDataSource")public MultiRouteDataSource exampleRouteDataSource() {MultiRouteDataSource multiDataSource = new MultiRouteDataSource();Map<Object, Object> targetDataSources = new HashMap<>();targetDataSources.put("master", masterDataSource());targetDataSources.put("slave", slaveDataSource());multiDataSource.setTargetDataSources(targetDataSources);multiDataSource.setDefaultTargetDataSource(masterDataSource());return multiDataSource;}/*** 注册ServletRegistrationBean* * @return*/@Beanpublic ServletRegistrationBean druidServlet() {ServletRegistrationBean reg = new ServletRegistrationBean();reg.setServlet(new StatViewServlet());reg.addUrlMappings("/druid/*");reg.addInitParameter("allow", ""); // 白名单 return reg;reg.addInitParameter("loginUsername", "duan");reg.addInitParameter("loginPassword", "123456");reg.addInitParameter("resetEnable", "false");return reg;}/*** 注册FilterRegistrationBean* * @return*/@Beanpublic 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");filterRegistrationBean.addInitParameter("principalCookieName", "USER_COOKIE");filterRegistrationBean.addInitParameter("principalSessionName", "USER_SESSION");filterRegistrationBean.addInitParameter("DruidWebStatFilter", "/*");return filterRegistrationBean;}
}

 

7、数据源上下文

/*** 数据源上下文** @author Lynch*/
public class DataSourceContext {private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();public static void setDataSource(String value) {contextHolder.set(value);}public static String getDataSource() {return contextHolder.get();}public static void clearDataSource() {contextHolder.remove();}
}

 

springboot两个数据库，8、DataSource路由类

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;import com.xinyartech.erp.config.DataSourceContext;/*** DataSource路由类* * 重写的函数决定了最后选择的DataSource** @author Lynch*/
public class MultiRouteDataSource extends AbstractRoutingDataSource {@Overrideprotected Object determineCurrentLookupKey() {// 通过绑定线程的数据源上下文实现多数据源的动态切换,有兴趣的可以去查阅资料或源码return DataSourceContext.getDataSource();}
}

 

9、修改上下文中的数据源就可以切换自己想要使用的数据源了 

public UserVO findUser(String username) {DataSourceContext.setDataSource("slave");UserVO userVO = userMapper.findByVO(username);System.out.println(userVO.getName());return null;
}

这种是在业务中使用代码设置数据源的方式，也可以使用AOP+注解的方式实现控制，还可以前端头部设置后端通过拦截器统一设置！