springboot+dubbo ApplicationConfig.application == null

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.alibaba.dubbo.spring.boot.DubboProviderAutoConfiguration': Invocation of init method failed; nested exception is java.lang.IllegalStateException: ApplicationConfig.application == null
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:139) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:414) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1770) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at com.mintoujf.springboot.SpringbootDubboProviderApplication.main(SpringbootDubboProviderApplication.java:12) [classes/:na]
Caused by: java.lang.IllegalStateException: ApplicationConfig.application == null
	at com.alibaba.dubbo.config.AbstractConfig.appendParameters(AbstractConfig.java:245) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.config.AbstractConfig.appendParameters(AbstractConfig.java:180) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.config.AbstractInterfaceConfig.loadRegistries(AbstractInterfaceConfig.java:175) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:355) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:316) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.config.ServiceConfig.export(ServiceConfig.java:215) ~[dubbo-2.6.0.jar:2.6.0]
	at com.alibaba.dubbo.spring.boot.DubboProviderAutoConfiguration.initProviderBean(DubboProviderAutoConfiguration.java:84) ~[dubbo-spring-boot-starter-2.0.0.jar:na]
	at com.alibaba.dubbo.spring.boot.DubboProviderAutoConfiguration.init(DubboProviderAutoConfiguration.java:45) ~[dubbo-spring-boot-starter-2.0.0.jar:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_151]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_151]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_151]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_151]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	... 18 common frames omitted
Caused by: java.lang.IllegalStateException: ApplicationConfig.application == null
	at com.alibaba.dubbo.config.AbstractConfig.appendParameters(AbstractConfig.java:230) ~[dubbo-2.6.0.jar:2.6.0]
	... 32 common frames omitted

学习springboot+dubbo集合的时候，遇到了个问题ApplicationConfig.application == null。
最后找到原因是由于版本冲突导致的。
之前我的pom依赖的dubbo-spring-boot-starter版本是2.0.0

<dependency>
            <groupId>com.alibaba.spring.boot</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>2.0.0</version>
 </dependency>

把版本号改成

 <version>1.0.2</version>

就行了