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解决mybatis-plus动态数据源切换不生效的问题

开发者 https://www.devze.com 2023-01-12 10:42 出处:网络 作者: 猴头蘑菇
目录一、问题描述二、环境1.依赖2.配置三、解决方法四、测试五、问题分析一、问题描述
目录
  • 一、问题描述
  • 二、环境
    • 1.依赖
    • 2.配置
  • 三、解决方法
    • 四、测试
      • 五、问题分析

        一、问题描述

        在我们项目中,既要连接mysql,又要连接TDEngine(taos),正确配置后也无法动态切换数据源执行sql

        二、环境

        1.依赖

        <!--连接另外一种数据库的驱动-->
                <dependency>
                    <groupId>com.taosdata.jdbc</groupId>
                    <artifactId>taos-jdbcdriver</artifactId>
        <!--            <version>2.0.32</version>-->
                    <version>3.0.0</version>
                </dependency>
                <!--myBATis plus 动态切换数据源的依赖-->
           		<dependency>
                    <groupId>com.baomidou</groupId>
                    <artifactId>dynamic-d编程客栈atasource-spring-boot-starter</artifactId>
                    <version>3.3.2</version>
                </dependency>
        

        2.配置

        spring:
          datasource:
            dynamic:
              strict: true
              primary: mysql
              datasource:
                mysql:
                  driver-class-name: com.mysql.cj.jdbc.Driver
                  url: jdbc:mysql://192.xxx.xxx.xxx:3306/db_iot?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai
                  username: root
                  password: 123456
                tdengine:
                  driver-class-name: com.taosdata.jdbc.TSDBDriver
                  url: jdbc:TAOS://192.xxx.xxx.xxx:6030/iot_data?timezone=UTC-8&charset=UTF-8&locale=en_US.UTF-8
                  username: root
                  password: taosdata
                mysql1:
                  driver-class-name开发者_JAVA: com.mysql.cj.jdbc.Driver
                  url: jdbc:mysql://192.xxx.xxx.xxx:3306/db_portal?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai
                  username: root
                  password: 123456
        
        
        
        

        三、解决方法

        直接上代码,最后会有问题分析,因为涉及到源码,这里暂时不讲

        这里的dynamicRoutingDataSource()不能有DynamicDataSourceAutoConfiguration里的那样命名和返回值,那样在注入时就会因为其他数据源的注入导致无法注入动态数据源,需要细化到具体的类型

        package com.xxx.project.iotconf.configs;
        
        import com.baomidou.dynamic.datasource.DynamicRoutingDataSource;
        import com.baomidou.dynamic.datasource.provider.DynamicDataSourceProvider;
        import com.baomidou.dynamic.datasource.provider.YmlDynamicDataSourceProvider;
        import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DataSourceProperty;
        import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DynamicDataSourceProperties;
        import org.springframework.beans.factory.annotation.Autowired;
        import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
        import org.springframework.context.annotation.Bean;
        import org.springframework.context.annotation.Configuration;
        import org.springframework.context.annotation.Primary;
        
        import Javax.sql.DataSource;
        import java.util.Map;
        
        
        @Configuration
        public class TDEngineConfig {
        
            @Autowired
            private DynamicDataSourceProperties properties;
        
            @Bean
            @ConditionalOnMissingBean
            @Primary
            public DynamicDataSourceProvider dynamicDataSourceProvider() {
                Map<String, DataSourceProperty> datasourceMap = this.properties.getDatasource();
                return new YmlDynamicDataSourceProvider(datasourceMap);
            }
        
            @Bean
            @ConditionalOnMissingBean
            public DynamicRoutingDataSource dynamicRoutingDataSource(DynamicDataSourceProvider dynamicDataSourceProvider) {
                DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
                dynamicRoutingDataSource.setPrimary(this.properties.getPrimary());
                dynamicRoutingDataSourcejavascript.setStrict(this.properties.getStrict());
                dynamicRoutingDataSource.setStrategy(this.properties.getStrategy());
                dynamicRoutingDataSource.setProvider(dynamicDataSourceProvider);
                dynamicRoutingDataSource.setP6spy(this.properties.getP6spy());
                dynamicRoutingDataSource.setSeata(this.properties.getSeata());
                Map<String, DataSource> dataSourceMap = dynamicDataSourceProvider.loadDataSources();
                for (String key : dataSourceMap.keySet()) {
                    dynamicRoutingDataSource.addDataSource(key, dataSourceMap.get(key));
                }
                return dynamicRou编程客栈tingDataSource;
            }
        
        }
        
        

        四、测试

        放入TAOS创建超表的SQL,由JdbcTemplate去执行,执行成功

        解决mybatis-plus动态数据源切换不生效的问题

        package com.xxx.project.iot.pulsar.handler;
        
        import com.baomidou.dynamic.datasource.annotation.DS;
        import com.shandy.project.api.basic.dto.SDevice;
        import com.shandy.project.api.basic.dto.Tuple2;
        import com.shandy.project.iot.pulsar.utils.ReflectUtils;
        import lombok.extern.slf4j.Slf4j;
        import org.springframework.beans.factory.annotation.Autowired;
        import org.springframework.jdbc.core.JdbcTemplate;
        import org.springframework.stereotype.Service;
        
        import javax.annotation.PostConstruct;
        import java.util.List;
        import java.util.Map;
        
        @Service
        @Slf4j
        public class DataHandler implements DsHandler{
        
            @Autowired
            private JdbcTemplate jdbcTemplate;
        
            @PostConstruct
            public void init() {
        
            }
        
            /**
             * 执行单条DDL sql
             */
            @DS(value = "tdengine")
            public void execute(String sql) {
                jdbcTemplate.execute(sql);
                log.info(sql);
            }
        
            /**
             * 执行单条DML sql
             */
            @DS(value = "tdengine")
            public List<Map<String, Object>> query(String sql, Object[] args) {
                log.info(String.format("%s,params is {%s}", sql, args));
                return jdbcTemplate.queryForList(sql, args);
            }
        
            /**
             * 保存设备数据(批量,多表多条)
             */
            @DS(value = "tdengine")
            public void batchInsertDevice(List<SDevice> devices, String table) {
                String[] sqls = null;
                jdbcTemplate.batchUpdate(sqls);
                log.info(sqls.toString());
            }
        
            /**
             * 单条插入
             *
             * @param device  消息结构体
             * @param mqttObj 模型对象,IMqttR或IMqttS对象
             */
            @DS(value = "tdengine")
            public void insertDevice(SDevice device, Object mqttObj) {
                Tuple2<String, List<Object>> t2 = ReflectUtils.getInsSql(mqttObj.getClass(), device);
                List<Object> list = t2.getField(1);
                String sql = t2.getField(0);
                jdbcTemplate.update(sql, list.toArray());
                log.info(sql);
            }
        }
        
        

        五、问题分析

        1.一开始执行时,总是报错误的SQL语句,要我检查Mysql的版本,所以从这个提示来看,是没有动态切换到我们的taos数据库的。

        什么原因呢?我们看com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DynamicDataSourceAutoConfiguration类的方法

           @Bean
            @ConditionalOnMissingBean
            public DataSource dataSource(DynamicDataSourceProvider dynamicDataSourceProvider) {
                DynamicRoutingDataSource dataSource = new DynamicRoutingDataSource();
                dataSource.setPrimary(this.properties.getPrimary());
                dataSource.setStrict(this.properties.getStrict());
                dataSource.setStrategy(this.properties.getStrategy());
                dataSource.setProvider(dynamicDataSourceProvider);
                dataSource.setP6spy(this.properties.getP6spy());
                dataSource.setSeata(this.properties.getSeata());
                return dataSource;
            }
        

        这里有个@ConditionalOnMissingBean注解,意思是当dataSource对象不存在时才会进行注入。

        我发现我除了配置了动态数据源,也配置了druid数据源,在项目启动是肯定是会注入druid的DataSource对象的,那就导致我们的动态数据源的DataSource对象无法注入,可能这就是切换不了的原因。这里或许可以尝试把druid数据源去掉,但我没有往这个方向去深究。

        spring.datasource.druid.db-type=mysql
        spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
        spring.datasource.druid.url=jdbc:mysql://192.xxx.xxx.xxx:3306/db_iot?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai
        spring.datasource.druid.username=root
        spring.datasource.druid.password=123456
        

        既然没有注入DynamicRoutingDataSource对象,我自己就写了上文中的TDEngineConfig去注入,其中方法和DynamicDataSourceAutoConfiguration类似,只是稍微做改造。

        在最开始我原封不动的把DynamicDataSourceAutoConfiguration方法抄下来,在执行SQL时报:dynamic-datasource could not find a datasource named tdengine

        异常来自于在DynamicRoutingDataSource的getDataSource()方法

        public DataSource getDataSource(String ds) {
                if (StringUtils.isEmpty(ds)) {
                    return this.determinePrimaryDataSource();
                } else if (!this.groupDataSources.isEmpty() &python& this.groupDataSources.containsKey(ds)) {
                    log.debug("dynamic-datasource switch to the datasource named [{}]", ds);
                    return ((GroupDataSource)this.groupDataSources.get(ds)).determineDataSource();
                } else if (this.dataSourceMap.containsKey(ds)) {
                    log.debug("dynamic-datasource switch to the datasource named [{}]", ds);
                    return (DataSource)this.dataSourceMap.get(ds);
                } else if (this.strict) {
                    throw new CannotFindDataSourceException("dynamic-datasource could not find a datasour编程客栈ce named" + ds);
                } else {
                    return this.determinePrimaryDataSource();
                }
            }
        

        从这里发现,DynamicRoutingDataSource的dataSourceMap是空的,那自然报错,但是DynamicDataSourceProperties的dataSourceMap并不是空的,所以配置并没有出错,只是项目在启动时没有填充DynamicRoutingDataSource的dataSourceMap,那不妨我们自己来完成这件事情。

        在TDEngineConfig的dynamicDataSourceProvider()方法中将properties的datasourceMap封装到YmlDynamicDataSourceProvider中,再看它的loadDataSources(),不就可以获取到Map<String, DataSource>类型的一个对象吗,我们把这个想办法赋值给DynamicRoutingDataSource的dataSourceMap

           public Map<String, DataSource> loadDataSources() {
                return this.createDataSourceMap(this.dataSourcePropertiesMap);
            }
        

        所以在TDEngineConfig的dynamicRoutingDataSource方法中通过如下代码获取到dataSourceMap

         Map<String, DataSource> dataSourceMap = dynamicDataSourceProvider.loadDataSources();
        

        再通过下面代码就将DynamicRoutingDataSource的dataSourceMap填充好了

         for (String key : dataSourceMap.keySet()) {
                    dynamicRoutingDataSource.addDataSource(key, dataSourceMap.get(key));
                }
        

        此时完成DynamicRoutingDataSource的注入。

        这样再调用SQL时,就可以获取@DS注解的value值,充当key去dataSourceMap里找到对应的数据源进行切换

        到此这篇关于解决mybatis-plus动态数据源切换不生效的问题的文章就介绍到这了,更多相关mybatis-plus动态数据源切换内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们!

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