Allow late binding ServletContextAwareProcessor

Update ServletContextAwareProcessor to allow subclasses to support late
binding of the ServletConfig and/or ServletContext. Allows for the
post-processor to be registered before the servlet environment has been
initialized.

Issue: SPR-10381

spring-web/src/main/java/org/springframework/web/context/support/ServletContextAwareProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@ import org.springframework.web.context.ServletContextAware;
  * underlying bean factory. Applications do not use this directly.
  *
  * @author Juergen Hoeller
+ * @author Phillip Webb
  * @since 12.03.2004
  * @see org.springframework.web.context.ServletContextAware
  * @see org.springframework.web.context.support.XmlWebApplicationContext#postProcessBeanFactory
@@ -44,6 +45,14 @@ public class ServletContextAwareProcessor implements BeanPostProcessor {
 	private ServletConfig servletConfig;
 
 
+	/**
+	 * Create a new ServletContextAwareProcessor without an initial context or config.
+	 * When this constructor is used the {@link #getServletContext()} and/or
+	 * {@link #getServletConfig()} methods should be overriden.
+	 */
+	protected ServletContextAwareProcessor() {
+	}
+
 	/**
 	 * Create a new ServletContextAwareProcessor for the given context.
 	 */
@@ -64,18 +73,36 @@ public class ServletContextAwareProcessor implements BeanPostProcessor {
 	public ServletContextAwareProcessor(ServletContext servletContext, ServletConfig servletConfig) {
 		this.servletContext = servletContext;
 		this.servletConfig = servletConfig;
-		if (servletContext == null && servletConfig != null) {
-			this.servletContext = servletConfig.getServletContext();
+	}
+
+
+	/**
+	 * Returns the {@link ServletContext} to be injected or {@code null}. This method
+	 * can be overridden by subclasses when a context is obtained after the post-processor
+	 * has been registered.
+	 */
+	protected ServletContext getServletContext() {
+		if(this.servletContext == null && getServletConfig() != null) {
+			return getServletConfig().getServletContext();
 		}
+		return this.servletContext;
 	}
 
+	/**
+	 * Returns the {@link ServletContext} to be injected or {@code null}. This method
+	 * can be overridden by subclasses when a context is obtained after the post-processor
+	 * has been registered.
+	 */
+	protected ServletConfig getServletConfig() {
+		return this.servletConfig;
+	}
 
 	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
-		if (this.servletContext != null && bean instanceof ServletContextAware) {
-			((ServletContextAware) bean).setServletContext(this.servletContext);
+		if (getServletContext() != null && bean instanceof ServletContextAware) {
+			((ServletContextAware) bean).setServletContext(getServletContext());
 		}
-		if (this.servletConfig != null && bean instanceof ServletConfigAware) {
-			((ServletConfigAware) bean).setServletConfig(this.servletConfig);
+		if (getServletConfig() != null && bean instanceof ServletConfigAware) {
+			((ServletConfigAware) bean).setServletConfig(getServletConfig());
 		}
 		return bean;
 	}