Unloadable nested classes in @Import should not fail if associated conditions exclude them anyway [SPR-11844]

[spring-projects-issues]

Dave Syer opened SPR-11844 and commented

If I add a @Configuration via an ImportSelector its nested classes are not loaded if they are @Conditional and the condition does not match (i.e. as expected). If you @Import the same class directly Spring loads the nested classes and there can be runtime errors (e.g. ClassNotFound).

---

Affects: 4.0.5

[spring-projects-issues]

Dave Syer commented

spring-attic/spring-framework-issues#79

[spring-projects-issues]

Stéphane Nicoll commented

Juergen Hoeller the test case has been merged here

[spring-projects-issues]

Juergen Hoeller commented

A quick note: Is this difference caused by the fact that ImportSelectors return class name Strings whereas @Import refers to the pre-loaded Class? Which nested class in HibernateJpaAutoConfiguration specifically is failing here - HibernateJpaVendorAdapter?

Juergen

[spring-projects-issues]

Dave Syer commented

That might be the difference, but the failure comes in the config parser, not when the outer class is loaded, so I was hoping there might be a non-destructive way to inspect the nested classes (e.g. convert the outer class to a string and then do it the same way as through the registrar).

I think there's only one nested class (it's in JpaBaseConfiguration):

	@Configuration
	@ConditionalOnWebApplication
	@ConditionalOnMissingBean({ OpenEntityManagerInViewInterceptor.class,
			OpenEntityManagerInViewFilter.class })
	@ConditionalOnExpression("${spring.jpa.openInView:${spring.jpa.open_in_view:true}}")
	protected static class JpaWebConfiguration extends WebMvcConfigurerAdapter {

		@Override
		public void addInterceptors(InterceptorRegistry registry) {
			registry.addWebRequestInterceptor(openEntityManagerInViewInterceptor());
		}

		@Bean
		public OpenEntityManagerInViewInterceptor openEntityManagerInViewInterceptor() {
			return new OpenEntityManagerInViewInterceptor();
		}

	}

[spring-projects-issues]

Stéphane Nicoll commented

JpaWebConfiguration is the "culprit" (extends from WebMvcConfigurerAdapter)

[spring-projects-issues]

Juergen Hoeller commented

Stéphane, please post the stacktrace of that JpaWebConfiguration loading failure here for a reference. Maybe we can indeed handle it along the lines that Dave suggested, flipping back to ASM-based processing in case of NoClassDefFoundErrors for nested classes.

Juergen

[spring-projects-issues]

Stéphane Nicoll commented

java.lang.NoClassDefFoundError: org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:455)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:367)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.getDeclaredClasses0(Native Method)
	at java.lang.Class.getDeclaredClasses(Class.java:1854)
	at org.springframework.context.annotation.ConfigurationClassParser.safeGetDeclaredClasses(ConfigurationClassParser.java:795)
	at org.springframework.context.annotation.ConfigurationClassParser.access$300(ConfigurationClassParser.java:94)
	at org.springframework.context.annotation.ConfigurationClassParser$SourceClass.getMemberClasses(ConfigurationClassParser.java:700)
	at org.springframework.context.annotation.ConfigurationClassParser.processMemberClasses(ConfigurationClassParser.java:306)
	at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:236)
	at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:219)
	at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:439)
	at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:262)
	at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:219)
	at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:186)
	at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:156)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:299)
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:243)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:254)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:94)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:609)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
	at org.springframework.issues.ReproTests.dirty(ReproTests.java:49)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.ClassNotFoundException: org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter
	at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:455)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:367)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.getDeclaredClasses0(Native Method)
	at java.lang.Class.getDeclaredClasses(Class.java:1854)

safeGetDeclaredClasses is just a private method I wrote that wraps sourceClass.getDeclaredClasses() with a try-catch

[spring-projects-issues]

Juergen Hoeller commented

Hmm, maybe we can indeed catch that case, back out just a bit, re-obtain the metadata for such a configuration class via ASM (MetadataReader) and try to resolve the member classes again...

Juergen

[spring-projects-issues]

Juergen Hoeller commented

We're explicitly catching NoClassDefFoundErrors from getDeclaredClasses() now, falling back to the ASM-based resolution path in such a case.

Juergen