Take the servlet context from the container, not a bean reference

The bean-definition wrap mode wired the resolver's ServletContext as a
RuntimeBeanReference to the "servletContext" bean. That bean is registered by
the container when the web server starts, so it exists only at runtime and has
no bean definition at all. Spring's ahead-of-time processing refreshes the
context without starting a web server, and determining the wrapper's
constructor requires the type of every supplied argument, so the reference
fails the whole run:

    AotBeanProcessingException: Error processing bean with name 'jspViewResolver'
    Caused by: NoSuchBeanDefinitionException: No bean named 'servletContext' available

SiteMeshViewResolver now implements ServletContextAware and takes its context
from the container, which is how a servlet-scoped collaborator is normally
supplied and leaves nothing in the definition to resolve early. A three-argument
constructor is added for that path; the four-argument one stays for callers that
build the resolver themselves, including the instance-level
SiteMeshViewResolverBeanPostProcessor, which constructs it outside any aware
callback. servletContextBeanName is deprecated on the definition post-processor,
where it no longer has an effect.

Author: codeconsole

spring-webmvc-sitemesh/src/main/java/org/sitemesh/webmvc/SiteMeshViewResolver.java

@@ -25,6 +25,7 @@
 import org.sitemesh.webapp.DispatchMode;
 
 import org.springframework.core.Ordered;
+import org.springframework.web.context.ServletContextAware;
 import org.springframework.web.servlet.SmartView;
 import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.ViewResolver;
@@ -37,14 +38,14 @@
  * are passed through un-wrapped so decorator renders themselves do not
  * trigger nested decoration.
  */
-public class SiteMeshViewResolver implements ViewResolver, Ordered {
+public class SiteMeshViewResolver implements ViewResolver, Ordered, ServletContextAware {
 
     private static final String DEFAULT_LAYOUT_PATH_PREFIX = "/layouts";
 
     private final ViewResolver innerViewResolver;
     private final ContentProcessor contentProcessor;
     private final DecoratorSelector<SiteMeshContext> decoratorSelector;
-    private final ServletContext servletContext;
+    private ServletContext servletContext;
 
     private String layoutPathPrefix = DEFAULT_LAYOUT_PATH_PREFIX;
     private int order;
@@ -53,7 +54,25 @@ public class SiteMeshViewResolver implements ViewResolver, Ordered {
 
     /**
      * Creates a resolver that wraps {@code innerViewResolver} and decorates
-     * the views it resolves.
+     * the views it resolves, taking its servlet context from the container
+     * through {@link ServletContextAware}.
+     *
+     * @param innerViewResolver the resolver whose views are wrapped
+     * @param contentProcessor parses buffered view output into a
+     *                         {@link org.sitemesh.content.Content}
+     * @param decoratorSelector selects the decorator path(s) for the parsed
+     *                          content
+     */
+    public SiteMeshViewResolver(ViewResolver innerViewResolver,
+                                ContentProcessor contentProcessor,
+                                DecoratorSelector<SiteMeshContext> decoratorSelector) {
+        this(innerViewResolver, contentProcessor, decoratorSelector, null);
+    }
+
+    /**
+     * Creates a resolver with the servlet context supplied directly, for
+     * callers constructing the resolver outside the container's
+     * {@link ServletContextAware} callback.
      *
      * @param innerViewResolver the resolver whose views are wrapped
      * @param contentProcessor parses buffered view output into a
@@ -79,6 +98,20 @@ public SiteMeshViewResolver(ViewResolver innerViewResolver,
                 : Ordered.LOWEST_PRECEDENCE;
     }
 
+    @Override
+    public void setServletContext(ServletContext servletContext) {
+        this.servletContext = servletContext;
+    }
+
+    /**
+     * The servlet context this resolver renders against.
+     *
+     * @return the servlet context
+     */
+    protected ServletContext getServletContext() {
+        return servletContext;
+    }
+
     @Override
     public View resolveViewName(String viewName, Locale locale) throws Exception {
         View innerView = innerViewResolver.resolveViewName(viewName, locale);

spring-webmvc-sitemesh/src/main/java/org/sitemesh/webmvc/SiteMeshViewResolverPostProcessor.java

@@ -42,8 +42,11 @@
  * under {@link #setSiteMeshViewResolverBeanName(String) siteMeshViewResolverBeanName}
  * (which by default replaces the original bean under its own name), with the
  * remaining constructor arguments wired as {@link RuntimeBeanReference
- * references} to the content processor, decorator selector and servlet
- * context beans.</p>
+ * references} to the content processor and decorator selector beans. The
+ * servlet context is not among them: the resolver receives it from the
+ * container through {@link org.springframework.web.context.ServletContextAware},
+ * which keeps the definition free of a reference to a bean that exists only
+ * once the web server has started.</p>
  *
  * <p>Embedding the original definition keeps the undecorated resolver out of
  * reach of {@code getBeansOfType(ViewResolver)} sweeps: a delegating resolver
@@ -114,7 +117,6 @@ public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) t
         }
         args.addIndexedArgumentValue(1, new RuntimeBeanReference(contentProcessorBeanName));
         args.addIndexedArgumentValue(2, new RuntimeBeanReference(decoratorSelectorBeanName));
-        args.addIndexedArgumentValue(3, new RuntimeBeanReference(servletContextBeanName));
         wrapperDefinition.getPropertyValues().add("dispatchMode", dispatchMode);
         wrapperDefinition.getPropertyValues().add("includeErrorPages", includeErrorPages);
 
@@ -309,7 +311,14 @@ public void setDecoratorSelectorBeanName(String decoratorSelectorBeanName) {
      * the resolver. Default: {@code "servletContext"}.
      *
      * @return the servlet context bean name
+     * @deprecated the resolver receives its servlet context from the container
+     * through {@link org.springframework.web.context.ServletContextAware}, so
+     * this name is no longer used. Registering the bean definition ahead of the
+     * container start means there is nothing to reference: the servlet context
+     * exists only once the web server has started, which is also why a
+     * reference to it cannot be processed ahead of time.
      */
+    @Deprecated(since = "3.3.0", forRemoval = true)
     public String getServletContextBeanName() {
         return servletContextBeanName;
     }
@@ -319,7 +328,10 @@ public String getServletContextBeanName() {
      * into the resolver.
      *
      * @param servletContextBeanName the servlet context bean name
+     * @deprecated see {@link #getServletContextBeanName()}; this setting has no
+     * effect.
      */
+    @Deprecated(since = "3.3.0", forRemoval = true)
     public void setServletContextBeanName(String servletContextBeanName) {
         this.servletContextBeanName = servletContextBeanName;
     }