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This article mainly explains "how to troubleshoot java.lang.ArrayStoreException anomalies in Spring Boot". The explanation in the article is simple and clear and easy to learn and understand. Please follow the editor's train of thought to study and learn "how to troubleshoot java.lang.ArrayStoreException anomalies in Spring Boot".

Java.lang.ArrayStoreException analysis

This demo explains how to troubleshoot the java.lang.ArrayStoreException that may occur when an spring boot 1 application is upgraded to spring boot 2.

Demo address: https://github.com/hengyunabc/spring-boot-inside/tree/master/demo-ArrayStoreException

There are two modules in demo, springboot1-starter and springboot2-demo.

In the springboot1-starter module, it is a simple HealthIndicator implementation

Public class MyHealthIndicator extends AbstractHealthIndicator {@ Override protected void doHealthCheck (Builder builder) throws Exception {builder.status (Status.UP); builder.withDetail ("hello", "world") @ Configuration@AutoConfigureBefore (EndpointAutoConfiguration.class) @ AutoConfigureAfter (HealthIndicatorAutoConfiguration.class) @ ConditionalOnClass (value = {HealthIndicator.class}) public class MyHealthIndicatorAutoConfiguration {@ Bean @ ConditionalOnMissingBean (MyHealthIndicator.class) @ ConditionalOnEnabledHealthIndicator ("my") public MyHealthIndicator myHealthIndicator () {return new MyHealthIndicator ();}}

Springboot2-demo is a simple springboot2 application that references the springboot1-starter module.

Import the project into IDE, execute the ArrayStoreExceptionDemoApplication in springboot2-demo, and the exception thrown is

Caused by: java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy at sun.reflect.annotation.AnnotationParser.parseClassArray (AnnotationParser.java:724) ~ [na:1.8.0_112] at sun.reflect.annotation.AnnotationParser.parseArray (AnnotationParser.java:531) ~ [na:1.8.0_112] at sun.reflect.annotation.AnnotationParser.parseMemberValue (AnnotationParser.java:355) ~ [na:1.8.0_112] at sun .reflect.annotation.AnnotationParser.parseAnnotation2 (AnnotationParser.java:286) ~ [na:1.8.0_112] at sun.reflect.annotation.AnnotationParser.parseAnnotations2 (AnnotationParser.java:120) ~ [na:1.8.0_112] at sun.reflect.annotation.AnnotationParser.parseAnnotations (AnnotationParser.java:72) ~ [na:1.8.0_112] at java.lang.Class.createAnnotationData (Class.java:3521) ~ [na:1.8. 01.112] at java.lang.Class.annotationData (Class.java:3510) ~ [na:1.8.0_112] at java.lang.Class.createAnnotationData (Class.java:3526) ~ [na:1.8.0_112] at java.lang.Class.annotationData (Class.java:3510) ~ [na:1.8.0_112] at java.lang.Class.getAnnotation (Class.java:3415) ~ [na: 1.8.0U112] at java.lang.reflect.AnnotatedElement.isAnnotationPresent (AnnotatedElement.java:258) ~ [na:1.8.0_112] at java.lang.Class.isAnnotationPresent (Class.java:3425) ~ [na:1.8.0_112] at org.springframework.core.annotation.AnnotatedElementUtils.hasAnnotation (AnnotatedElementUtils.java:575) ~ [spring-core-5.0.4.RELEASE.jar:5.0.4.RELEASE] At org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.isHandler (RequestMappingHandlerMapping.java:177) ~ [spring-webmvc-5.0.4.RELEASE.jar:5.0.4.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods (AbstractHandlerMethodMapping.java:217) ~ [spring-webmvc-5.0.4.RELEASE.jar:5.0.4.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet ( AbstractHandlerMethodMapping.java:188) ~ [spring-webmvc-5.0.4.RELEASE.jar:5.0.4.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet (RequestMappingHandlerMapping.java:129) ~ [spring-webmvc-5.0.4.RELEASE.jar:5.0.4.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods (AbstractAutowireCapableBeanFactory.java:1769) ~ [spring-beans-5.0.4. RELEASE.jar:5.0.4.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean (AbstractAutowireCapableBeanFactory.java:1706) ~ [spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]. 16 common frames omitted using Java Exception Breakpoint

Let's troubleshoot this problem.

In IDE, create a new breakpoint of type Java Exception Breakpoint (if you don't know how to add it, you can search the corresponding IDE usage document), and the exception class is the java.lang.ArrayStoreException thrown above.

When the breakpoint takes effect, look at the parameters of the AnnotationUtils.findAnnotation (Class, Class, Set) line: 686 function.

Can be found

Clazz is class com.example.springboot1starter.MyHealthIndicatorAutoConfiguration$$EnhancerBySpringCGLIB$$945c1f.

AnnotationType is interface org.springframework.boot.actuate.endpoint.annotation.Endpoint.

An error occurred while trying to find @ Endpoint information from MyHealthIndicatorAutoConfiguration.

There is no @ Endpoint on MyHealthIndicatorAutoConfiguration, but why throw java.lang.ArrayStoreException?

Try to reproduce the exception with a simple example

First try to new MyHealthIndicatorAutoConfiguration directly:

Public static void main (String] args) {MyHealthIndicatorAutoConfiguration cc = new MyHealthIndicatorAutoConfiguration ();}

I thought an exception would be thrown, but found that the execution was normal.

If you take a closer look at the exception stack, you can see that the exception was thrown at at java.lang.Class.getDeclaredAnnotation (Class.java:3458), then try the following code:

Public static void main (String [] args) {MyHealthIndicatorAutoConfiguration.class.getDeclaredAnnotation (Endpoint.class);}

It is found that the exception can be reproduced:

Exception in thread "main" 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 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.getDeclaredAnnotation (Class.java:3458) Why is it java.lang.ArrayStoreException

Take a closer look at the exception message: java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy

ArrayStoreException is an array out-of-bounds exception that has only one String message and no cause.

So let's try to break points in the constructor of sun.reflect.annotation.TypeNotPresentExceptionProxy.

Public class TypeNotPresentExceptionProxy extends ExceptionProxy {private static final long serialVersionUID = 5565925172427947573L; String typeName; Throwable cause; public TypeNotPresentExceptionProxy (String typeName, Throwable cause) {this.typeName = typeName; this.cause = cause;}

At the breakpoint, we can find:

TypeName is org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration.

Cause is java.lang.ClassNotFoundException: org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration

Finally, the truth came out that the class org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration could not be found.

So how did it become ArrayStoreException?

If you look at the code carefully, you can see that AnnotationParser.parseClassValue wraps the exception as Object.

/ / sun.reflect.annotation.AnnotationParser.parseClassValue (ByteBuffer, ConstantPool, Class) private static Object parseClassValue (ByteBuffer buf, ConstantPool constPool, Class container) {int classIndex = buf.getShort () & 0xFFF; try {try {String sig = constPool.getUTF8At (classIndex) Return parseSig (sig, container);} catch (IllegalArgumentException ex) {/ / support obsolete early jsr175 format class files return constPool.getClassAt (classIndex);}} catch (NoClassDefFoundError e) {return new TypeNotPresentExceptionProxy ("[unknown]", e) } catch (TypeNotPresentException e) {return new TypeNotPresentExceptionProxy (e.typeName (), e.getCause ());}}

Then try to set it directly to the array in sun.reflect.annotation.AnnotationParser.parseClassArray (int, ByteBuffer, ConstantPool, Class).

/ / sun.reflect.annotation.AnnotationParser.parseClassArray (int, ByteBuffer, ConstantPool, Class) result [I] = parseClassValue (buf, constPool, container)

Here, the array is out of bounds, and ArrayStoreException only has the type information of the out-of-bounds Object, that is, the above

Java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy solves the problem

If you find that it is java.lang.ClassNotFoundException: org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration, then add the @ ConditionalOnClass check:

@ Configuration@AutoConfigureBefore (EndpointAutoConfiguration.class) @ AutoConfigureAfter (HealthIndicatorAutoConfiguration.class) @ ConditionalOnClass (value = {HealthIndicator.class, EndpointAutoConfiguration.class}) public class MyHealthIndicatorAutoConfiguration {

To be exact, spring boot2 changed the package of some classes:

The name of the class in spring boot 1 is:

Org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration

The name of the class in spring boot 2 is:

Org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration

Thank you for reading, the above is the content of "how to troubleshoot java.lang.ArrayStoreException anomalies in Spring Boot". After the study of this article, I believe you have a deeper understanding of how to troubleshoot java.lang.ArrayStoreException anomalies in Spring Boot, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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