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-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());
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、测试
放入TAOS创建超表的SQL，由JdbcTemplate去执行，执行成功
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() {
}
@DS(value = "tdengine")
public void execute(String sql) {
jdbcTemplate.execute(sql);
log.info(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);
}
@DS(value = "tdengine")
public void batchInsertDevice(List<SDevice> devices, String table) {
String[] sqls = null;
jdbcTemplate.batchUpdate(sqls);
log.info(sqls.toString());
}
@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() && 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();
}
}
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
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