revised JSP-based views to never fail when trying to setting forward attributes (SPR-6623)

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/InternalResourceView.java

@@ -20,7 +20,6 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
-
 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -70,7 +69,7 @@ public class InternalResourceView extends AbstractUrlBasedView {
 
 	private boolean alwaysInclude = false;
 
-	private Boolean exposeForwardAttributes;
+	private volatile Boolean exposeForwardAttributes;
 
 	private boolean exposeContextBeansAsAttributes = false;
 
@@ -181,7 +180,7 @@ public class InternalResourceView extends AbstractUrlBasedView {
 	}
 
 	/**
-	 * Checks whether we need explictly expose the Servlet 2.4 request attributes
+	 * Checks whether we need to explicitly expose the Servlet 2.4 request attributes
 	 * by default.
 	 * @see #setExposeForwardAttributes
 	 * @see #exposeForwardRequestAttributes(javax.servlet.http.HttpServletRequest)
@@ -330,7 +329,13 @@ public class InternalResourceView extends AbstractUrlBasedView {
 	 */
 	protected void exposeForwardRequestAttributes(HttpServletRequest request) {
 		if (this.exposeForwardAttributes != null && this.exposeForwardAttributes) {
-			WebUtils.exposeForwardRequestAttributes(request);
+			try {
+				WebUtils.exposeForwardRequestAttributes(request);
+			}
+			catch (Exception ex) {
+				// Servlet container rejected to set internal attributes, e.g. on TriFork.
+				this.exposeForwardAttributes = Boolean.FALSE;
+			}
 		}
 	}
 

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/tiles2/TilesView.java

@@ -55,6 +55,25 @@ import org.springframework.web.util.WebUtils;
  */
 public class TilesView extends AbstractUrlBasedView {
 
+	private volatile boolean exposeForwardAttributes = false;
+
+
+	/**
+	 * Checks whether we need to explicitly expose the Servlet 2.4 request attributes
+	 * by default.
+	 * <p>This will be done by default on Servlet containers up until 2.4, and skipped
+	 * for Servlet 2.5 and above. Note that Servlet containers at 2.4 level and above
+	 * should expose those attributes automatically! This feature exists for
+	 * Servlet 2.3 containers and misbehaving 2.4 containers only.
+	 */
+	@Override
+	protected void initServletContext(ServletContext sc) {
+		if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
+			this.exposeForwardAttributes = true;
+		}
+	}
+
+
 	@Override
 	public boolean checkResource(final Locale locale) throws Exception {
 		TilesContainer container = ServletUtil.getContainer(getServletContext());
@@ -91,9 +110,14 @@ public class TilesView extends AbstractUrlBasedView {
 			// Tiles is going to use a forward, but some web containers (e.g. OC4J 10.1.3)
 			// do not properly expose the Servlet 2.4 forward request attributes... However,
 			// must not do this on Servlet 2.5 or above, mainly for GlassFish compatibility.
-			ServletContext sc = getServletContext();
-			if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
-				WebUtils.exposeForwardRequestAttributes(request);
+			if (this.exposeForwardAttributes) {
+				try {
+					WebUtils.exposeForwardRequestAttributes(request);
+				}
+				catch (Exception ex) {
+					// Servlet container rejected to set internal attributes, e.g. on TriFork.
+					this.exposeForwardAttributes = false;
+				}
 			}
 		}