spring boot 启动报错，找不到DataSource

报错信息如下：

16:39:11.372 1653 [main] WARN o.s.b.c.e.AnnotationConfigEmbeddedWebApplicationContext [AbstractApplicationContext.java:551] -  Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: URL [jar:file:/data/cdn-device-monitor-client/cdn-device-monitor-client.jar!/BOOT-INF/lib/spring-boot-autoconfigure-1.5.6.RELEASE.jar!/org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$EmbeddedDatabaseConfiguration.class]; nested exception is java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$EmbeddedDatabaseConfiguration due to org/springframework/dao/DataAccessException not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
16:39:11.374 1655 [main] ERROR o.s.b.f.s.DefaultListableBeanFactory [DefaultSingletonBeanRegistry.java:581] -  Destroy method on bean with name 'org.springframework.boot.autoconfigure.internalCachingMetadataReaderFactory' threw an exception
java.lang.IllegalStateException: ApplicationEventMulticaster not initialized - call 'refresh' before multicasting events via the context: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@2401f4c3: startup date [Mon Mar 04 16:39:10 CST 2019]; root of context hierarchy
        at org.springframework.context.support.AbstractApplicationContext.getApplicationEventMulticaster(AbstractApplicationContext.java:414)
        at org.springframework.context.support.ApplicationListenerDetector.postProcessBeforeDestruction(ApplicationListenerDetector.java:97)
        at org.springframework.beans.factory.support.DisposableBeanAdapter.destroy(DisposableBeanAdapter.java:253)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroyBean(DefaultSingletonBeanRegistry.java:578)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingleton(DefaultSingletonBeanRegistry.java:554)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingleton(DefaultListableBeanFactory.java:961)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingletons(DefaultSingletonBeanRegistry.java:523)
        at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.destroySingletons(FactoryBeanRegistrySupport.java:230)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingletons(DefaultListableBeanFactory.java:968)
        at org.springframework.context.support.AbstractApplicationContext.destroyBeans(AbstractApplicationContext.java:1030)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:556)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
        at DeviceClientStartMain.main(DeviceClientStartMain.java:26)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
        at org.springframework.boot.loader.PropertiesLauncher.main(PropertiesLauncher.java:593)
16:39:11.377 1658 [main] INFO o.s.b.a.l.AutoConfigurationReportLoggingInitializer [AutoConfigurationReportLoggingInitializer.java:101] -  

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
16:39:11.380 1661 [main] ERROR o.s.boot.SpringApplication [SpringApplication.java:771] -  Application startup failed
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: URL [jar:file:/data/cdn-device-monitor-client/cdn-device-monitor-client.jar!/BOOT-INF/lib/spring-boot-autoconfigure-1.5.6.RELEASE.jar!/org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$EmbeddedDatabaseConfiguration.class]; nested exception is java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$EmbeddedDatabaseConfiguration due to org/springframework/dao/DataAccessException not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
        at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:311)
        at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:272)
        at org.springframework.context.annotation.ComponentScanAnnotationParser.parse(ComponentScanAnnotationParser.java:135)
        at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:287)
        at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:245)
        at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:198)
        at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:167)
        at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308)
        at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228)
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270)
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
        at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:687)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:525)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
        at DeviceClientStartMain.main(DeviceClientStartMain.java:26)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
        at org.springframework.boot.loader.PropertiesLauncher.main(PropertiesLauncher.java:593)
Caused by: java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$EmbeddedDatabaseConfiguration due to org/springframework/dao/DataAccessException not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
        at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:55)
        at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:102)
        at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:81)
        at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:64)
        at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.isConditionMatch(ClassPathScanningCandidateComponentProvider.java:371)
        at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.isCandidateComponent(ClassPathScanningCandidateComponentProvider.java:355)
        at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:288)
        ... 27 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/springframework/dao/DataAccessException
        at org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$EmbeddedDatabaseCondition.getMatchOutcome(DataSourceAutoConfiguration.java:211)
        at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:47)
        ... 33 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.dao.DataAccessException
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:93)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 35 common frames omitted

问题背景，简单的springboot项目，未依赖任何jdbc、datasource相关jar包，但启动时报以上错误信息

解决方案：Application***.java 启动main方法类不能直接放在java包下面，需新建子包，子包放在java下面，然后将application.java放在子包里面

参考：https://segmentfault.com/a/1190000004493460，感谢作者