解決mybatis-plus動態數據源切換不生效的問題
一、問題描述
在我們項目中,既要連接mysql,又要連接TDEngine(taos),正確配置後也無法動態切換數據源執行sql
二、環境
1.依賴
<!--連接另外一種數據庫的驅動--> <dependency> <groupId>com.taosdata.jdbc</groupId> <artifactId>taos-jdbcdriver</artifactId> <!-- <version>2.0.32</version>--> <version>3.0.0</version> </dependency> <!--mybatis plus 動態切換數據源的依賴--> <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,最後會有問題分析,因為涉及到源碼,這裡暫時不講
這裡的dynamicRoutingDataSource()不能有DynamicDataSourceAutoConfiguration裡的那樣命名和返回值,那樣在註入時就會因為其他數據源的註入導致無法註入動態數據源,需要細化到具體的類型
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、測試
放入TAOS創建超表的SQL,由JdbcTemplate去執行,執行成功
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() { } /** * 執行單條DDL sql */ @DS(value = "tdengine") public void execute(String sql) { jdbcTemplate.execute(sql); log.info(sql); } /** * 執行單條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); } /** * 保存設備數據(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 消息結構體 * @param mqttObj 模型對象,IMqttR或IMqttS對象 */ @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、問題分析
1.一開始執行時,總是報錯誤的SQL語句,要我檢查Mysql的版本,所以從這個提示來看,是沒有動態切換到我們的taos數據庫的。
什麼原因呢?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; }
這裡有個@ConditionalOnMissingBean註解,意思是當dataSource對象不存在時才會進行註入。
我發現我除瞭配置瞭動態數據源,也配置瞭druid數據源,在項目啟動是肯定是會註入druid的DataSource對象的,那就導致我們的動態數據源的DataSource對象無法註入,可能這就是切換不瞭的原因。這裡或許可以嘗試把druid數據源去掉,但我沒有往這個方向去深究。
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
既然沒有註入DynamicRoutingDataSource對象,我自己就寫瞭上文中的TDEngineConfig去註入,其中方法和DynamicDataSourceAutoConfiguration類似,隻是稍微做改造。
在最開始我原封不動的把DynamicDataSourceAutoConfiguration方法抄下來,在執行SQL時報:dynamic-datasource could not find a datasource named tdengine
異常來自於在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(); } }
從這裡發現,DynamicRoutingDataSource的dataSourceMap是空的,那自然報錯,但是DynamicDataSourceProperties的dataSourceMap並不是空的,所以配置並沒有出錯,隻是項目在啟動時沒有填充DynamicRoutingDataSource的dataSourceMap,那不妨我們自己來完成這件事情。
在TDEngineConfig的dynamicDataSourceProvider()方法中將properties的datasourceMap封裝到YmlDynamicDataSourceProvider中,再看它的loadDataSources(),不就可以獲取到Map<String, DataSource>類型的一個對象嗎,我們把這個想辦法賦值給DynamicRoutingDataSource的dataSourceMap
public Map<String, DataSource> loadDataSources() { return this.createDataSourceMap(this.dataSourcePropertiesMap); }
所以在TDEngineConfig的dynamicRoutingDataSource方法中通過如下代碼獲取到dataSourceMap
Map<String, DataSource> dataSourceMap = dynamicDataSourceProvider.loadDataSources();
再通過下面代碼就將DynamicRoutingDataSource的dataSourceMap填充好瞭
for (String key : dataSourceMap.keySet()) { dynamicRoutingDataSource.addDataSource(key, dataSourceMap.get(key)); }
此時完成DynamicRoutingDataSource的註入。
這樣再調用SQL時,就可以獲取@DS註解的value值,充當key去dataSourceMap裡找到對應的數據源進行切換
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