SPR-6467 - Allow ContentNegotiatingViewResolver to be strict ant return a 406 if no view found

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

@@ -31,6 +31,7 @@ import javax.activation.FileTypeMap;
 import javax.activation.MimetypesFileTypeMap;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.core.OrderComparator;
@@ -115,6 +116,8 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 
 	private String parameterName = "format";
 	
+	private boolean useNotAcceptableStatusCode = false;
+
 	private boolean ignoreAcceptHeader = false;
 
 	private ConcurrentMap<String, MediaType> mediaTypes = new ConcurrentHashMap<String, MediaType>();
@@ -125,7 +128,6 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 
 	private List<ViewResolver> viewResolvers;
 
-
 	public void setOrder(int order) {
 		this.order = order;
 	}
@@ -174,6 +176,20 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 		this.ignoreAcceptHeader = ignoreAcceptHeader;
 	}
 
+	/**
+	 * Indicates whether a {@link HttpServletResponse#SC_NOT_ACCEPTABLE 406 Not Acceptable} status code should be
+	 * returned if no suitable view can be found.
+	 *
+	 * <p>Default is {@code false}, meaning that this view resolver returns {@code null} for
+	 * {@link #resolveViewName(String, Locale)} when an acceptable view cannot be found. This will allow for view
+	 * resolvers chaining. When this property is set to {@code true}, 
+	 * {@link #resolveViewName(String, Locale)} will respond with a view that sets the response status to
+	 * {@code 406 Not Acceptable} instead.
+	 */
+	public void setUseNotAcceptableStatusCode(boolean useNotAcceptableStatusCode) {
+		this.useNotAcceptableStatusCode = useNotAcceptableStatusCode;
+	}
+
 	/**
 	 * Sets the mapping from file extensions to media types.
 	 * <p>When this mapping is not set or when an extension is not present, this view resolver
@@ -337,7 +353,6 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 			Collections.sort(requestedMediaTypes);
 		}
 
-		SortedMap<MediaType, View> views = new TreeMap<MediaType, View>();
 		List<View> candidateViews = new ArrayList<View>();
 		for (ViewResolver viewResolver : this.viewResolvers) {
 			View view = viewResolver.resolveViewName(viewName, locale);
@@ -349,6 +364,7 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 			candidateViews.addAll(this.defaultViews);
 		}
 
+		SortedMap<MediaType, View> views = new TreeMap<MediaType, View>();
 		for (View candidateView : candidateViews) {
 			String contentType = candidateView.getContentType();
 			if (StringUtils.hasText(contentType)) {
@@ -373,11 +389,10 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 			return view;
 		}
 		else {
-			return null;
+			return useNotAcceptableStatusCode ? new NotAcceptableView() : null;
 		}
 	}
 
-
 	/**
 	 * Inner class to avoid hard-coded JAF dependency.
 	 */
@@ -421,4 +436,15 @@ public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport
 		}
 	}
 
+	private static class NotAcceptableView implements View {
+
+		public String getContentType() {
+			return null;
+		}
+
+		public void render(Map<String, ?> model, HttpServletRequest request, HttpServletResponse response)
+				throws Exception {
+			response.setStatus(HttpServletResponse.SC_NOT_ACCEPTABLE);
+		}
+	}
 }

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/view/ContentNegotiatingViewResolverTests.java

@@ -30,6 +30,7 @@ import org.junit.Test;
 
 import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
 import org.springframework.web.servlet.View;
@@ -305,4 +306,58 @@ public class ContentNegotiatingViewResolverTests {
 		verify(viewResolverMock, viewMock);
 	}
 
+	@Test
+	public void resolveViewNoMatch() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/test");
+		request.addHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9");
+		RequestContextHolder.setRequestAttributes(new ServletRequestAttributes(request));
+
+		ViewResolver viewResolverMock = createMock(ViewResolver.class);
+		viewResolver.setViewResolvers(Collections.singletonList(viewResolverMock));
+
+		View viewMock = createMock("application_xml", View.class);
+
+		String viewName = "view";
+		Locale locale = Locale.ENGLISH;
+
+		expect(viewResolverMock.resolveViewName(viewName, locale)).andReturn(viewMock);
+		expect(viewMock.getContentType()).andReturn("application/pdf");
+
+		replay(viewResolverMock, viewMock);
+
+		View result = viewResolver.resolveViewName(viewName, locale);
+		assertNull("Invalid view", result);
+
+		verify(viewResolverMock, viewMock);
+	}
+
+	@Test
+	public void resolveViewNoMatchUseUnacceptableStatus() throws Exception {
+		viewResolver.setUseNotAcceptableStatusCode(true);
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/test");
+		request.addHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9");
+		RequestContextHolder.setRequestAttributes(new ServletRequestAttributes(request));
+
+		ViewResolver viewResolverMock = createMock(ViewResolver.class);
+		viewResolver.setViewResolvers(Collections.singletonList(viewResolverMock));
+
+		View viewMock = createMock("application_xml", View.class);
+
+		String viewName = "view";
+		Locale locale = Locale.ENGLISH;
+
+		expect(viewResolverMock.resolveViewName(viewName, locale)).andReturn(viewMock);
+		expect(viewMock.getContentType()).andReturn("application/pdf");
+
+		replay(viewResolverMock, viewMock);
+
+		View result = viewResolver.resolveViewName(viewName, locale);
+		assertNotNull("Invalid view", result);
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		result.render(null, request, response);
+		assertEquals("Invalid status code set", 406, response.getStatus());
+
+		verify(viewResolverMock, viewMock);
+	}
+
 }