解決mybatis-plus動(dòng)態(tài)數(shù)據(jù)源切換不生效的問(wèn)題

更新時(shí)間：2023年01月11日 16:08:42 作者：猴頭蘑菇

本文主要介紹了解決mybatis-plus動(dòng)態(tài)數(shù)據(jù)源切換不生效的問(wèn)題，文中通過(guò)示例代碼介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來(lái)一起學(xué)習(xí)學(xué)習(xí)吧

一、問(wèn)題描述

在我們項(xiàng)目中，既要連接mysql，又要連接TDEngine（taos），正確配置后也無(wú)法動(dòng)態(tài)切換數(shù)據(jù)源執(zhí)行sql

二、環(huán)境

1.依賴

<!--連接另外一種數(shù)據(jù)庫(kù)的驅(qū)動(dòng)-->
        <dependency>
            <groupId>com.taosdata.jdbc</groupId>
            <artifactId>taos-jdbcdriver</artifactId>
<!--            <version>2.0.32</version>-->
            <version>3.0.0</version>
        </dependency>
        <!--mybatis plus 動(dòng)態(tài)切換數(shù)據(jù)源的依賴-->
   		<dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-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: 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、解決方法

直接上代碼，最后會(huì)有問(wèn)題分析，因?yàn)樯婕暗皆创a，這里暫時(shí)不講
這里的dynamicRoutingDataSource()不能有DynamicDataSourceAutoConfiguration里的那樣命名和返回值，那樣在注入時(shí)就會(huì)因?yàn)槠渌麛?shù)據(jù)源的注入導(dǎo)致無(wú)法注入動(dòng)態(tài)數(shù)據(jù)源，需要細(xì)化到具體的類型

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());
        dynamicRoutingDataSource.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 dynamicRoutingDataSource;
    }

}

四、測(cè)試

放入TAOS創(chuàng)建超表的SQL，由JdbcTemplate去執(zhí)行，執(zhí)行成功

在這里插入圖片描述

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() {

    }

    /**
     * 執(zhí)行單條DDL sql
     */
    @DS(value = "tdengine")
    public void execute(String sql) {
        jdbcTemplate.execute(sql);
        log.info(sql);
    }

    /**
     * 執(zhí)行單條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);
    }

    /**
     * 保存設(shè)備數(shù)據(jù)(批量，多表多條)
     */
    @DS(value = "tdengine")
    public void batchInsertDevice(List<SDevice> devices, String table) {
        String[] sqls = null;
        jdbcTemplate.batchUpdate(sqls);
        log.info(sqls.toString());
    }

    /**
     * 單條插入
     *
     * @param device  消息結(jié)構(gòu)體
     * @param mqttObj 模型對(duì)象，IMqttR或IMqttS對(duì)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、問(wèn)題分析

1.一開(kāi)始執(zhí)行時(shí)，總是報(bào)錯(cuò)誤的SQL語(yǔ)句，要我檢查Mysql的版本，所以從這個(gè)提示來(lái)看，是沒(méi)有動(dòng)態(tài)切換到我們的taos數(shù)據(jù)庫(kù)的。
什么原因呢？我們看com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DynamicDataSourceAutoConfiguration類的方法

   @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;
    }

這里有個(gè)@ConditionalOnMissingBean注解，意思是當(dāng)dataSource對(duì)象不存在時(shí)才會(huì)進(jìn)行注入。
我發(fā)現(xiàn)我除了配置了動(dòng)態(tài)數(shù)據(jù)源，也配置了druid數(shù)據(jù)源，在項(xiàng)目啟動(dòng)是肯定是會(huì)注入druid的DataSource對(duì)象的，那就導(dǎo)致我們的動(dòng)態(tài)數(shù)據(jù)源的DataSource對(duì)象無(wú)法注入，可能這就是切換不了的原因。這里或許可以嘗試把druid數(shù)據(jù)源去掉，但我沒(méi)有往這個(gè)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

既然沒(méi)有注入DynamicRoutingDataSource對(duì)象，我自己就寫了上文中的TDEngineConfig去注入，其中方法和DynamicDataSourceAutoConfiguration類似，只是稍微做改造。

在最開(kāi)始我原封不動(dòng)的把DynamicDataSourceAutoConfiguration方法抄下來(lái)，在執(zhí)行SQL時(shí)報(bào)：dynamic-datasource could not find a datasource named tdengine
異常來(lái)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() && 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 datasource named" + ds);
        } else {
            return this.determinePrimaryDataSource();
        }
    }

從這里發(fā)現(xiàn)，DynamicRoutingDataSource的dataSourceMap是空的，那自然報(bào)錯(cuò)，但是DynamicDataSourceProperties的dataSourceMap并不是空的，所以配置并沒(méi)有出錯(cuò)，只是項(xiàng)目在啟動(dòng)時(shí)沒(méi)有填充DynamicRoutingDataSource的dataSourceMap，那不妨我們自己來(lái)完成這件事情。
在TDEngineConfig的dynamicDataSourceProvider()方法中將properties的datasourceMap封裝到Y(jié)mlDynamicDataSourceProvider中，再看它的loadDataSources()，不就可以獲取到Map<String, DataSource>類型的一個(gè)對(duì)象嗎，我們把這個(gè)想辦法賦值給DynamicRoutingDataSource的dataSourceMap

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

所以在TDEngineConfig的dynamicRoutingDataSource方法中通過(guò)如下代碼獲取到dataSourceMap

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

再通過(guò)下面代碼就將DynamicRoutingDataSource的dataSourceMap填充好了

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

此時(shí)完成DynamicRoutingDataSource的注入。
這樣再調(diào)用SQL時(shí)，就可以獲取@DS注解的value值，充當(dāng)key去dataSourceMap里找到對(duì)應(yīng)的數(shù)據(jù)源進(jìn)行切換

到此這篇關(guān)于解決mybatis-plus動(dòng)態(tài)數(shù)據(jù)源切換不生效的問(wèn)題的文章就介紹到這了,更多相關(guān)mybatis-plus動(dòng)態(tài)數(shù)據(jù)源切換內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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