使用springboot 2 構建專案，除錯程式碼的時候出現瞭如下的報錯資訊

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class
 
]: Invocation of init method failed; nested exception is java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1708)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:581
 
)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222
 
)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1325)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1291)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1096)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:818)
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:724)
    ... 36 common frames omitted
Caused by: java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy
    at sun.reflect.annotation.AnnotationParser.parseClassArray(AnnotationParser.java:724)
    at sun.reflect.annotation.AnnotationParser.parseArray(AnnotationParser.java:531)
    at sun.reflect.annotation.AnnotationParser.parseMemberValue(AnnotationParser.java:355)
    at sun.reflect.annotation.AnnotationParser.parseAnnotation2(AnnotationParser.java:286)
    at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:120)
    at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:72)
    at java.lang.Class.createAnnotationData(Class.java:3521)
    at java.lang.Class.annotationData(Class.java:3510)
    at java.lang.Class.createAnnotationData(Class.java:3526)
    at java.lang.Class.annotationData(Class.java:3510)
    at java.lang.Class.getAnnotation(Class.java:3415)
    at java.lang.reflect.AnnotatedElement.isAnnotationPresent(AnnotatedElement.java:258)
    at java.lang.Class.isAnnotationPresent(Class.java:3425)
    at org.springframework.core.annotation.AnnotatedElementUtils.hasAnnotation(AnnotatedElementUtils.java:573)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.isHandler(RequestMappingHandlerMapping.java:177)
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods(AbstractHandlerMethodMapping.java:217)
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet(AbstractHandlerMethodMapping.java:188)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet(RequestMappingHandlerMapping.java:129)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1767)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1704)
    ... 50 common frames omitted

第一眼看到這個問題的時候感覺頭都比較大，那隻能除錯斷定，新建一個斷點，型別是Java Exception Breakpoint，異常類是上面丟擲來的java.lang.ArrayStoreException，

通過除錯檢視是找不到org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration這個類，而AnnotationParser.parseClassValue把異常包裝成為Object，然後在sun.reflect.annotation.AnnotationParser.parseClassArray(int, ByteBuffer, ConstantPool, Class

result[i] = parseClassValue(buf, constPool, container);

而這裡陣列越界了，ArrayStoreException只有越界的Object的型別資訊，也就是上面的

java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy

發現是java.lang.ClassNotFoundException: org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration，則加上@ConditionalOnClass的檢查就可以了.

準確來說是spring boot2把一些類的package改了：

spring boot 1裡類名是：

org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration
spring boot 2裡類名是：

org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration

而我解決的辦法就比較簡單粗暴，把專案再細分化，把一些有影響的pom專案（activiti-spring-boot-starter-basic）放到一個新的專案中去，獨立成一個模組來使用。