SpringBoot项目启动报错java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy

问题

今天启动业余学习项目里的某服务A发现启动失败，报错信息如下：

[ ERROR] [2025-01-05 15:41:26,083] [main] com.cdfive.springboot.startup.ApplicationStartupExceptionReporter [30] - error=>
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.reflect.Executable.declaredAnnotations(Executable.java:599)
	at java.lang.reflect.Executable.declaredAnnotations(Executable.java:597)
	at java.lang.reflect.Executable.getDeclaredAnnotations(Executable.java:588)
	at java.lang.reflect.Method.getDeclaredAnnotations(Method.java:630)
	at org.springframework.core.annotation.AnnotationsScanner.getDeclaredAnnotations(AnnotationsScanner.java:454)
	at org.springframework.core.annotation.AnnotationsScanner.isKnownEmpty(AnnotationsScanner.java:492)
	at org.springframework.core.annotation.TypeMappedAnnotations.from(TypeMappedAnnotations.java:251)
	at org.springframework.core.annotation.MergedAnnotations.from(MergedAnnotations.java:351)
	at org.springframework.core.annotation.MergedAnnotations.from(MergedAnnotations.java:330)
	at org.springframework.core.annotation.AnnotatedElementUtils.findAnnotations(AnnotatedElementUtils.java:764)
	at org.springframework.core.annotation.AnnotatedElementUtils.hasAnnotation(AnnotatedElementUtils.java:531)
	at org.springframework.context.annotation.BeanAnnotationHelper.isBeanAnnotated(BeanAnnotationHelper.java:41)
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.isMatch(ConfigurationClassEnhancer.java:407)
	at org.springframework.context.annotation.ConfigurationClassEnhancer$ConditionalCallbackFilter.accept(ConfigurationClassEnhancer.java:192)
	at org.springframework.cglib.proxy.Enhancer.emitMethods(Enhancer.java:1217)
	at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:726)
	at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)
	at org.springframework.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
	at org.springframework.cglib.core.ClassLoaderAwareGeneratorStrategy.generate(ClassLoaderAwareGeneratorStrategy.java:57)
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:358)
	at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:585)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:110)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:108)
	at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
	at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
	at java.util.concurrent.FutureTask.run(FutureTask.java)
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:134)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:319)
	at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:572)
	at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:419)
	at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:137)
	at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:109)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:433)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:258)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:291)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:131)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:707)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:533)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236)
	at com.cdfive.web.WebApplication.main(WebApplication.java:16)

第一次看到这个报错：java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy
异常堆栈信息里没有项目模块里相关的东西，初步看不出来哪里的问题。

分析&解决

考虑上周在本机尝试安装新版本IDEA，后面又还原安装了老版本，尝试刷新整个项目Maven依赖，然后mvn clean package重新启动该模块，发现还是启动失败；
尝试启动项目里另一个模块服务B，启动成功。

咦？这什么情况。。

查看Git Log想想自己怎么改了什么，看到最近对对cdfive-sentinel、cdfive-demo-mybatis模块有修改和优化，
cdfive-sentinel模块里增加了feign的集成扩展，通过feign的Capability和InvocationHandlerFactory和sentinel的API进行集成，
cdfive-demo-mybatis模块里引入knife4j-spring-ui依赖，修复了影响其使用的问题。

其中，cdfive-demo-mybatis是个独立的demo模块，服务A和服务B依赖它，而都有对cdfive-sentinel模块的依赖。

为什么服务A启动失败，服务B启动成功呢？

注意到服务A没有feign的依赖，而服务B有，在cdfive-sentinel模块里对feign的依赖<scope>为provided。

通过搜索找到一些博客分享，尝试在java.lang.ArrayStoreException类的构造函数打断点：

public ArrayStoreException() {
        super();
    }

public ArrayStoreException(String s) {
    super(s);
}

在断点的方法调用栈里，看到上一级AnnotationParser#parseClassArray(...)里，找到了有个变量的类型是com.cdfive.sentinel.config.SentinelAutoConfiguration，
是扩展sentinel的自动配置类，上周正好修改过。

打开SentinelAutoConfiguration类，查看新添加的代码：

@ConditionalOnClass(Feign.Builder.class)
@Bean
public SentinelBeanPostProcessor sentinelBeanPostProcessor() {
    SentinelBeanPostProcessor sentinelBeanPostProcessor = new SentinelBeanPostProcessor();
    return sentinelBeanPostProcessor;
}

新添加1个SentinelBeanPostProcessor的Bean，想通过@ConditionalOnClass注解实现当class包里有Feign.Builder时创建该Bean，
而服务A里没有feign的依赖包。

根据@ConditionalOnClass注解字面理解，它是判断class是否存在来决定是否创建Bean，
这里将注解用在方法上，遇到了问题。

查看@ConditionOnClass注解的注释：

**
 * {@link Conditional @Conditional} that only matches when the specified classes are on
 * the classpath.
 * <p>
 * A {@link #value()} can be safely specified on {@code @Configuration} classes as the
 * annotation metadata is parsed by using ASM before the class is loaded. Extra care is
 * required when placed on {@code @Bean} methods, consider isolating the condition in a
 * separate {@code Configuration} class, in particular if the return type of the method
 * matches the {@link #value target of the condition}.
 *
 * @author Phillip Webb
 * @since 1.0.0
 */
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Conditional(OnClassCondition.class)
public @interface ConditionalOnClass {
    ...
}

根据查询的资料：

`@ConditionalOnClass`如果添加在类的方法里时要格外小心，考虑将条件隔离在单独的Configuration类中，
建议`@ConditionalOnClass`在类级别使用，如果在方法上使用，考虑使用它的name属性来指定。

因此尝试将@ConditionalOnClass(Feign.Builder.class)修改为@ConditionalOnClass(name = "feign.Feign.Builder")，
通过名称而不是类型来指定，重新编译项目并启动服务A，启动成功。

参考

• springboot启动报sun.reflect.annotation.TypeNotPresentExceptionProxy
  https://zhuanlan.zhihu.com/p/462068881

• ConditionalOnClass not working for Bean methods on Java 8
  https://github.com/spring-projects/spring-boot/issues/27846