NullPointerException in error path of ConstructorResolver when constructing a @Bean from a factory method [SPR-7629]

[spring-projects-issues]

Keith Donald opened SPR-7629 and commented

I accidentally left off the SpEL expression delimiter #{} for @Value when defining the following @Bean signature:

@Bean
@Scope(value="request", proxyMode=ScopedProxyMode.INTERFACES)
public TwitterOperations twitterApi(AccountProvider<TwitterOperations> twitterAccountProvider, @Value("#{request.getAttribute('account')}") Account account) {
    return twitterAccountProvider.getApi(accountId(account));
}

So instead of the above, my code read:

@Bean
@Scope(value="request", proxyMode=ScopedProxyMode.INTERFACES)
public TwitterOperations twitterApi(AccountProvider<TwitterOperations> twitterAccountProvider, @Value("request.getAttribute('account')") Account account) {
    return twitterAccountProvider.getApi(accountId(account));
}

I confirmed using the debugger this generated a type conversion exception. However, this exception was caught and then the following NullPointerException was thrown:

java.lang.NullPointerException
	org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:551)
	org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:983)
	org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:879)
	org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
	org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
	org.springframework.beans.factory.support.AbstractBeanFactory$2.getObject(AbstractBeanFactory.java:329)
	org.springframework.web.context.request.AbstractRequestAttributesScope.get(AbstractRequestAttributesScope.java:43)
	org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:325)
	org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
	org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:33)
	org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:182)
	$Proxy16.search(Unknown Source)
	com.springsource.greenhouse.groups.GroupsController.eventView(GroupsController.java:50)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
	org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426)
	org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:343)
	org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
	org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.oauth.provider.OAuthProviderProcessingFilter.doFilter(OAuthProviderProcessingFilter.java:172)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.oauth.provider.OAuthProviderProcessingFilter.doFilter(OAuthProviderProcessingFilter.java:192)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.oauth.provider.OAuthProviderProcessingFilter.doFilter(OAuthProviderProcessingFilter.java:192)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.access.channel.ChannelProcessingFilter.doFilter(ChannelProcessingFilter.java:109)
	org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
	org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:149)
	org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
	org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
	org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	org.springframework.web.flash.FlashMapFilter.doFilterInternal(FlashMapFilter.java:33)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

After correcting my error, things worked as expected but it took awhile for me to identify my mistake without a suitable error message to help me.

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Affects: 3.0.4

Referenced from: commits 0610632