InternalResourceViewResolver's exposure of context beans is now available at UrlBasedViewResolver level

Issue: SPR-8064

Author: jhoeller

spring-webmvc/src/main/java/org/springframework/web/servlet/view/AbstractView.java

@@ -18,10 +18,13 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Properties;
+import java.util.Set;
 import java.util.StringTokenizer;
 import javax.servlet.ServletOutputStream;
 import javax.servlet.http.HttpServletRequest;
@@ -30,6 +33,7 @@
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.http.MediaType;
 import org.springframework.util.CollectionUtils;
+import org.springframework.web.context.support.ContextExposingHttpServletRequest;
 import org.springframework.web.context.support.WebApplicationObjectSupport;
 import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.support.RequestContext;
@@ -68,12 +72,14 @@ public abstract class AbstractView extends WebApplicationObjectSupport implement
 
 	private String requestContextAttribute;
 
-	/** Map of static attributes, keyed by attribute name (String) */
 	private final Map<String, Object> staticAttributes = new LinkedHashMap<String, Object>();
 
-	/** Whether or not the view should add path variables in the model */
 	private boolean exposePathVariables = true;
 
+	private boolean exposeContextBeansAsAttributes = false;
+
+	private Set<String> exposedContextBeanNames;
+
 
 	/**
 	 * Set the view's name. Helpful for traceability.
@@ -248,6 +254,36 @@ public boolean isExposePathVariables() {
 		return this.exposePathVariables;
 	}
 
+	/**
+	 * Set whether to make all Spring beans in the application context accessible
+	 * as request attributes, through lazy checking once an attribute gets accessed.
+	 * <p>This will make all such beans accessible in plain {@code ${...}}
+	 * expressions in a JSP 2.0 page, as well as in JSTL's {@code c:out}
+	 * value expressions.
+	 * <p>Default is "false". Switch this flag on to transparently expose all
+	 * Spring beans in the request attribute namespace.
+	 * <p><b>NOTE:</b> Context beans will override any custom request or session
+	 * attributes of the same name that have been manually added. However, model
+	 * attributes (as explicitly exposed to this view) of the same name will
+	 * always override context beans.
+	 * @see #getRequestToExpose
+	 */
+	public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
+		this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
+	}
+
+	/**
+	 * Specify the names of beans in the context which are supposed to be exposed.
+	 * If this is non-null, only the specified beans are eligible for exposure as
+	 * attributes.
+	 * <p>If you'd like to expose all Spring beans in the application context, switch
+	 * the {@link #setExposeContextBeansAsAttributes "exposeContextBeansAsAttributes"}
+	 * flag on but do not list specific bean names for this property.
+	 */
+	public void setExposedContextBeanNames(String... exposedContextBeanNames) {
+		this.exposedContextBeanNames = new HashSet<String>(Arrays.asList(exposedContextBeanNames));
+	}
+
 
 	/**
 	 * Prepares the view given the specified model, merging it with static
@@ -264,7 +300,7 @@ public void render(Map<String, ?> model, HttpServletRequest request, HttpServlet
 
 		Map<String, Object> mergedModel = createMergedOutputModel(model, request, response);
 		prepareResponse(request, response);
-		renderMergedOutputModel(mergedModel, request, response);
+		renderMergedOutputModel(mergedModel, getRequestToExpose(request), response);
 	}
 
 	/**
@@ -276,12 +312,13 @@ protected Map<String, Object> createMergedOutputModel(Map<String, ?> model, Http
 
 		@SuppressWarnings("unchecked")
 		Map<String, Object> pathVars = (this.exposePathVariables ?
-			(Map<String, Object>) request.getAttribute(View.PATH_VARIABLES) : null);
+				(Map<String, Object>) request.getAttribute(View.PATH_VARIABLES) : null);
 
 		// Consolidate static and dynamic model attributes.
 		int size = this.staticAttributes.size();
-		size += (model != null) ? model.size() : 0;
-		size += (pathVars != null) ? pathVars.size() : 0;
+		size += (model != null ? model.size() : 0);
+		size += (pathVars != null ? pathVars.size() : 0);
+
 		Map<String, Object> mergedModel = new LinkedHashMap<String, Object>(size);
 		mergedModel.putAll(this.staticAttributes);
 		if (pathVars != null) {
@@ -344,6 +381,24 @@ protected boolean generatesDownloadContent() {
 		return false;
 	}
 
+	/**
+	 * Get the request handle to expose to {@link #renderMergedOutputModel}, i.e. to the view.
+	 * <p>The default implementation wraps the original request for exposure of Spring beans
+	 * as request attributes (if demanded).
+	 * @param originalRequest the original servlet request as provided by the engine
+	 * @return the wrapped request, or the original request if no wrapping is necessary
+	 * @see #setExposeContextBeansAsAttributes
+	 * @see #setExposedContextBeanNames
+	 * @see org.springframework.web.context.support.ContextExposingHttpServletRequest
+	 */
+	protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest) {
+		if (this.exposeContextBeansAsAttributes || this.exposedContextBeanNames != null) {
+			return new ContextExposingHttpServletRequest(
+					originalRequest, getWebApplicationContext(), this.exposedContextBeanNames);
+		}
+		return originalRequest;
+	}
+
 	/**
 	 * Subclasses must implement this method to actually render the view.
 	 * <p>The first step will be preparing the request: In the JSP case,

spring-webmvc/src/main/java/org/springframework/web/servlet/view/InternalResourceView.java

@@ -68,10 +68,6 @@ public class InternalResourceView extends AbstractUrlBasedView {
 
 	private boolean alwaysInclude = false;
 
-	private boolean exposeContextBeansAsAttributes = false;
-
-	private Set<String> exposedContextBeanNames;
-
 	private boolean preventDispatchLoop = false;
 
 
@@ -115,36 +111,6 @@ public void setAlwaysInclude(boolean alwaysInclude) {
 		this.alwaysInclude = alwaysInclude;
 	}
 
-	/**
-	 * Set whether to make all Spring beans in the application context accessible
-	 * as request attributes, through lazy checking once an attribute gets accessed.
-	 * <p>This will make all such beans accessible in plain {@code ${...}}
-	 * expressions in a JSP 2.0 page, as well as in JSTL's {@code c:out}
-	 * value expressions.
-	 * <p>Default is "false". Switch this flag on to transparently expose all
-	 * Spring beans in the request attribute namespace.
-	 * <p><b>NOTE:</b> Context beans will override any custom request or session
-	 * attributes of the same name that have been manually added. However, model
-	 * attributes (as explicitly exposed to this view) of the same name will
-	 * always override context beans.
-	 * @see #getRequestToExpose
-	 */
-	public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
-		this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
-	}
-
-	/**
-	 * Specify the names of beans in the context which are supposed to be exposed.
-	 * If this is non-null, only the specified beans are eligible for exposure as
-	 * attributes.
-	 * <p>If you'd like to expose all Spring beans in the application context, switch
-	 * the {@link #setExposeContextBeansAsAttributes "exposeContextBeansAsAttributes"}
-	 * flag on but do not list specific bean names for this property.
-	 */
-	public void setExposedContextBeanNames(String... exposedContextBeanNames) {
-		this.exposedContextBeanNames = new HashSet<String>(Arrays.asList(exposedContextBeanNames));
-	}
-
 	/**
 	 * Set whether to explicitly prevent dispatching back to the
 	 * current handler path.
@@ -173,58 +139,38 @@ protected boolean isContextRequired() {
 	protected void renderMergedOutputModel(
 			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
 
-		// Determine which request handle to expose to the RequestDispatcher.
-		HttpServletRequest requestToExpose = getRequestToExpose(request);
-
 		// Expose the model object as request attributes.
-		exposeModelAsRequestAttributes(model, requestToExpose);
+		exposeModelAsRequestAttributes(model, request);
 
 		// Expose helpers as request attributes, if any.
-		exposeHelpers(requestToExpose);
+		exposeHelpers(request);
 
 		// Determine the path for the request dispatcher.
-		String dispatcherPath = prepareForRendering(requestToExpose, response);
+		String dispatcherPath = prepareForRendering(request, response);
 
 		// Obtain a RequestDispatcher for the target resource (typically a JSP).
-		RequestDispatcher rd = getRequestDispatcher(requestToExpose, dispatcherPath);
+		RequestDispatcher rd = getRequestDispatcher(request, dispatcherPath);
 		if (rd == null) {
 			throw new ServletException("Could not get RequestDispatcher for [" + getUrl() +
 					"]: Check that the corresponding file exists within your web application archive!");
 		}
 
 		// If already included or response already committed, perform include, else forward.
-		if (useInclude(requestToExpose, response)) {
+		if (useInclude(request, response)) {
 			response.setContentType(getContentType());
 			if (logger.isDebugEnabled()) {
 				logger.debug("Including resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'");
 			}
-			rd.include(requestToExpose, response);
+			rd.include(request, response);
 		}
 
 		else {
 			// Note: The forwarded resource is supposed to determine the content type itself.
 			if (logger.isDebugEnabled()) {
 				logger.debug("Forwarding to resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'");
 			}
-			rd.forward(requestToExpose, response);
-		}
-	}
-
-	/**
-	 * Get the request handle to expose to the RequestDispatcher, i.e. to the view.
-	 * <p>The default implementation wraps the original request for exposure of
-	 * Spring beans as request attributes (if demanded).
-	 * @param originalRequest the original servlet request as provided by the engine
-	 * @return the wrapped request, or the original request if no wrapping is necessary
-	 * @see #setExposeContextBeansAsAttributes
-	 * @see org.springframework.web.context.support.ContextExposingHttpServletRequest
-	 */
-	protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest) {
-		if (this.exposeContextBeansAsAttributes || this.exposedContextBeanNames != null) {
-			return new ContextExposingHttpServletRequest(
-					originalRequest, getWebApplicationContext(), this.exposedContextBeanNames);
+			rd.forward(request, response);
 		}
-		return originalRequest;
 	}
 
 	/**

spring-webmvc/src/main/java/org/springframework/web/servlet/view/InternalResourceViewResolver.java

@@ -52,10 +52,6 @@ public class InternalResourceViewResolver extends UrlBasedViewResolver {
 
 	private Boolean alwaysInclude;
 
-	private Boolean exposeContextBeansAsAttributes;
-
-	private String[] exposedContextBeanNames;
-
 
 	/**
 	 * Sets the default {@link #setViewClass view class} to {@link #requiredViewClass}:
@@ -89,42 +85,13 @@ public void setAlwaysInclude(boolean alwaysInclude) {
 		this.alwaysInclude = alwaysInclude;
 	}
 
-	/**
-	 * Set whether to make all Spring beans in the application context accessible
-	 * as request attributes, through lazy checking once an attribute gets accessed.
-	 * <p>This will make all such beans accessible in plain {@code ${...}}
-	 * expressions in a JSP 2.0 page, as well as in JSTL's {@code c:out}
-	 * value expressions.
-	 * <p>Default is "false".
-	 * @see InternalResourceView#setExposeContextBeansAsAttributes
-	 */
-	public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
-		this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
-	}
-
-	/**
-	 * Specify the names of beans in the context which are supposed to be exposed.
-	 * If this is non-null, only the specified beans are eligible for exposure as
-	 * attributes.
-	 * @see InternalResourceView#setExposedContextBeanNames
-	 */
-	public void setExposedContextBeanNames(String... exposedContextBeanNames) {
-		this.exposedContextBeanNames = exposedContextBeanNames;
-	}
-
 
 	@Override
 	protected AbstractUrlBasedView buildView(String viewName) throws Exception {
 		InternalResourceView view = (InternalResourceView) super.buildView(viewName);
 		if (this.alwaysInclude != null) {
 			view.setAlwaysInclude(this.alwaysInclude);
 		}
-		if (this.exposeContextBeansAsAttributes != null) {
-			view.setExposeContextBeansAsAttributes(this.exposeContextBeansAsAttributes);
-		}
-		if (this.exposedContextBeanNames != null) {
-			view.setExposedContextBeanNames(this.exposedContextBeanNames);
-		}
 		view.setPreventDispatchLoop(true);
 		return view;
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/view/UrlBasedViewResolver.java

@@ -119,6 +119,10 @@ public class UrlBasedViewResolver extends AbstractCachingViewResolver implements
 
 	private Boolean exposePathVariables;
 
+	private Boolean exposeContextBeansAsAttributes;
+
+	private String[] exposedContextBeanNames;
+
 	private String[] viewNames;
 
 	private int order = Integer.MAX_VALUE;
@@ -327,6 +331,37 @@ protected Boolean getExposePathVariables() {
 		return this.exposePathVariables;
 	}
 
+	/**
+	 * Set whether to make all Spring beans in the application context accessible
+	 * as request attributes, through lazy checking once an attribute gets accessed.
+	 * <p>This will make all such beans accessible in plain {@code ${...}}
+	 * expressions in a JSP 2.0 page, as well as in JSTL's {@code c:out}
+	 * value expressions.
+	 * <p>Default is "false".
+	 * @see AbstractView#setExposeContextBeansAsAttributes
+	 */
+	public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
+		this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
+	}
+
+	protected Boolean getExposeContextBeansAsAttributes() {
+		return this.exposeContextBeansAsAttributes;
+	}
+
+	/**
+	 * Specify the names of beans in the context which are supposed to be exposed.
+	 * If this is non-null, only the specified beans are eligible for exposure as
+	 * attributes.
+	 * @see AbstractView#setExposedContextBeanNames
+	 */
+	public void setExposedContextBeanNames(String... exposedContextBeanNames) {
+		this.exposedContextBeanNames = exposedContextBeanNames;
+	}
+
+	protected String[] getExposedContextBeanNames() {
+		return this.exposedContextBeanNames;
+	}
+
 	/**
 	 * Set the view names (or name patterns) that can be handled by this
 	 * {@link org.springframework.web.servlet.ViewResolver}. View names can contain
@@ -482,6 +517,14 @@ protected AbstractUrlBasedView buildView(String viewName) throws Exception {
 		if (exposePathVariables != null) {
 			view.setExposePathVariables(exposePathVariables);
 		}
+		Boolean exposeContextBeansAsAttributes = getExposeContextBeansAsAttributes();
+		if (exposeContextBeansAsAttributes != null) {
+			view.setExposeContextBeansAsAttributes(exposeContextBeansAsAttributes);
+		}
+		String[] exposedContextBeanNames = getExposedContextBeanNames();
+		if (exposedContextBeanNames != null) {
+			view.setExposedContextBeanNames(exposedContextBeanNames);
+		}
 
 		return view;
 	}