Make BeanNameViewResolver use a supplied ApplicationContext

With the deprecation of the XmlViewResolver and ResourceBundleViewResolver it is harder to have multiple ViewResolver instances to resolve a view with the same name but for a different content-types.

I thought of using the BeanNameViewResolver however as that is ApplicationContextAware it gets the ApplicationContext it runs in injected, resulting in an error.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pdfViewResolver' defined in class path resource [com/apress/spring6recipes/court/config/ViewResolverConfiguration.class]: Cannot reinitialize with different application context: current one is [org.springframework.context.support.GenericApplicationContext@61b718e, started on Tue Oct 25 17:31:00 GMT 2022], passed-in one is [WebApplicationContext for namespace 'dispatcher-servlet', started on Tue Oct 25 17:31:00 GMT 2022]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:606)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:931)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:916)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:584)
        at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:699)
        at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:576)
        at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:530)
        at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:169)
        at jakarta.servlet.GenericServlet.init(GenericServlet.java:158)
        at jakarta.servlet.http.HttpServlet.init(HttpServlet.java:140)
        at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:995)
        at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:696)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:128)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:119)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:400)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1739)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.base/java.lang.Thread.run(Thread.java:1589)
Caused by: org.springframework.context.ApplicationContextException: Cannot reinitialize with different application context: current one is [org.springframework.context.support.GenericApplicationContext@61b718e, started on Tue Oct 25 17:31:00 GMT 2022], passed-in one is [WebApplicationContext for namespace 'dispatcher-servlet', started on Tue Oct 25 17:31:00 GMT 2022]
        at org.springframework.context.support.ApplicationObjectSupport.setApplicationContext(ApplicationObjectSupport.java:83)
        at org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces(ApplicationContextAwareProcessor.java:109)
        at org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization(ApplicationContextAwareProcessor.java:85)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:420)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1745)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:599)

It would be nice if we could use the constructor to pass in an ApplicationContext to be used with the BeanNameViewResolver much like the DispatcherServlet does. This way you can have a small ApplicationContext with functional beans to resolve to views with the same name but for different content-types.

Start by reading BeanNameViewResolver, ApplicationObjectSupport, and the DispatcherServlet context-handling path described in the stack trace. Determine how a supplied ApplicationContext should be used without conflicting with ApplicationContextAware, then add focused coverage showing resolution from the supplied context and run the relevant Spring MVC tests.