技術標籤：java bugbugjar

1. 啟動專案報錯之jar包衝突（Caused by: java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy ）

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 
2020-12-22 17:56:32.564 ERROR 4512 --- [           main]
 
 o.s.boot.SpringApplication               : Application run failed 
 
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:1694) ~[spring-
 
beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:573) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:548) ~[spring-context-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:386) [spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1242) [spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1230) [spring-boot-2.0.8.RELEASE.jar:2.0.8.RELEASE] 
        at yooo.yun.com.GatewayApplication.main(GatewayApplication.java:17) [classes/:na] 
Caused by: java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy 
        at sun.reflect.annotation.AnnotationParser.parseClassArray(AnnotationParser.java:724) ~[na:1.8.0_231] 
        at sun.reflect.annotation.AnnotationParser.parseArray(AnnotationParser.java:531) ~[na:1.8.0_231] 
        at sun.reflect.annotation.AnnotationParser.parseMemberValue(AnnotationParser.java:355) ~[na:1.8.0_231] 
        at sun.reflect.annotation.AnnotationParser.parseAnnotation2(AnnotationParser.java:286) ~[na:1.8.0_231] 
        at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:120) ~[na:1.8.0_231] 
        at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:72) ~[na:1.8.0_231] 
        at java.lang.Class.createAnnotationData(Class.java:3521) ~[na:1.8.0_231] 
        at java.lang.Class.annotationData(Class.java:3510) ~[na:1.8.0_231] 
        at java.lang.Class.createAnnotationData(Class.java:3526) ~[na:1.8.0_231] 
        at java.lang.Class.annotationData(Class.java:3510) ~[na:1.8.0_231] 
        at java.lang.Class.getAnnotation(Class.java:3415) ~[na:1.8.0_231] 
        at java.lang.reflect.AnnotatedElement.isAnnotationPresent(AnnotatedElement.java:258) ~[na:1.8.0_231] 
        at java.lang.Class.isAnnotationPresent(Class.java:3425) ~[na:1.8.0_231] 
        at org.springframework.core.annotation.AnnotatedElementUtils.hasAnnotation(AnnotatedElementUtils.java:570) ~[spring-core-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.isHandler(RequestMappingHandlerMapping.java:177) ~[spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods(AbstractHandlerMethodMapping.java:218) ~[spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet(AbstractHandlerMethodMapping.java:189) ~[spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet(RequestMappingHandlerMapping.java:136) ~[spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1753) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1690) ~[spring-beans-5.0.12.RELEASE.jar:5.0.12.RELEASE] 
        ... 16 common frames omitted 
 
 
Process finished with exit code 1 

2. 導致錯誤原因：jar包衝突；

• 今天在編寫Zuul回退機制類時， ServiceFallBackProvider implements ZuulFallbackProvider ，匯入jar包後重啟專案報錯；

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-netflix-core</artifactId>
    <version>1.3.1.RELEASE</version>
</dependency>

• 檢視jar包發現有兩個版本不同的jar包；
  
• ZuulFallbackProvider 屬於低版本1.3.1.RELEASE，但是SpringCloud預設整合了Hystrix，所以是高版本2.0.2.RELEASE版本；

3. 解決方法

• 使用預設版本，刪除低版本jar包，高版本Zuul的回退機制類是FallbackProvider，所以只需實現FallbackProvider即可。重啟服務正常啟動。