SPR-5625 - Allow for exceptions to be annotated with a @ResponseStatus annotation

org.springframework.web.servlet/src/main/java/org/springframework/web/bind/annotation/ResponseStatus.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.bind.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.http.HttpStatus;
+
+/**
+ * Marks an exception class with the status code and reason that should be returned whenever said exception is thrown.
+ *
+ * @author Arjen Poutsma
+ * @since 3.0
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface ResponseStatus {
+
+	/**
+	 * The status code to use for the response.
+	 *
+	 * @see javax.servlet.http.HttpServletResponse#setStatus(int)
+	 */
+	HttpStatus value();
+
+	/**
+	 * The reason to be used for the response. <p>If this element is not set, it will default to the standard status
+	 * message for the status code.
+	 *
+	 * @see javax.servlet.http.HttpServletResponse#sendError(int, String)
+	 */
+	String reason() default "";
+
+}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/DispatcherServlet.properties

@@ -13,7 +13,8 @@ org.springframework.web.servlet.HandlerAdapter=org.springframework.web.servlet.m
 	org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,\
 	org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter
 
-org.springframework.web.servlet.HandlerExceptionResolver=org.springframework.web.servlet.handler.DefaultHandlerExceptionResolver
+org.springframework.web.servlet.HandlerExceptionResolver=org.springframework.web.servlet.handler.DefaultHandlerExceptionResolver,\
+	org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver
 
 org.springframework.web.servlet.RequestToViewNameTranslator=org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator
 

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/annotation/ResponseStatusExceptionResolver.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2002-2009 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.mvc.annotation;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.util.StringUtils;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.servlet.ModelAndView;
+import org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver;
+
+/**
+ * Implementation of the {@link org.springframework.web.servlet.HandlerExceptionResolver HandlerExceptionResolver}
+ * interface that uses the {@link ResponseStatus @ResponseStatus} annotation to map exceptions to HTTP status codes.
+ *
+ * @author Arjen Poutsma
+ * @since 3.0
+ */
+public class ResponseStatusExceptionResolver extends AbstractHandlerExceptionResolver {
+
+	@Override
+	protected ModelAndView doResolveException(HttpServletRequest request,
+			HttpServletResponse response,
+			Object handler,
+			Exception ex) {
+		ResponseStatus responseStatus = AnnotationUtils.findAnnotation(ex.getClass(), ResponseStatus.class);
+		if (responseStatus != null) {
+			try {
+				return resolveResponseStatus(responseStatus, request, response, handler, ex);
+			}
+			catch (Exception resolveEx) {
+				logger.warn("Handling of @ResponseStatus resulted in Exception", resolveEx);
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Template method that handles {@link ResponseStatus @ResponseStatus} annotation. <p>Default implementation send a
+	 * response error using {@link HttpServletResponse#sendError(int)}, or {@link HttpServletResponse#sendError(int,
+	 * String)} if the annotation has a {@linkplain ResponseStatus#reason() reason}. Returns an empty ModelAndView.
+	 *
+	 * @param responseStatus the annotation
+	 * @param request current HTTP request
+	 * @param response current HTTP response
+	 * @param handler the executed handler, or <code>null</code> if none chosen at the time of the exception (for example,
+	 * if multipart resolution failed)
+	 * @param ex the exception that got thrown during handler execution
+	 * @return a corresponding ModelAndView to forward to, or <code>null</code> for default processing
+	 */
+	protected ModelAndView resolveResponseStatus(ResponseStatus responseStatus,
+			HttpServletRequest request,
+			HttpServletResponse response,
+			Object handler,
+			Exception ex) throws Exception {
+		int statusCode = responseStatus.value().value();
+		String reason = responseStatus.reason();
+		if (!StringUtils.hasLength(reason)) {
+			response.sendError(statusCode);
+		}
+		else {
+			response.sendError(statusCode, reason);
+		}
+		return new ModelAndView();
+	}
+}

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ResponseStatusExceptionResolverTests.java

@@ -0,0 +1,66 @@
+package org.springframework.web.servlet.mvc.annotation;
+
+import static org.junit.Assert.*;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.servlet.ModelAndView;
+
+/** @author Arjen Poutsma */
+public class ResponseStatusExceptionResolverTests {
+
+	private ResponseStatusExceptionResolver exceptionResolver;
+
+	private MockHttpServletRequest request;
+
+	private MockHttpServletResponse response;
+
+	@Before
+	public void setUp() {
+		exceptionResolver = new ResponseStatusExceptionResolver();
+		request = new MockHttpServletRequest();
+		response = new MockHttpServletResponse();
+		request.setMethod("GET");
+	}
+
+	@Test
+	public void statusCode() {
+		StatusCodeException ex = new StatusCodeException();
+		ModelAndView mav = exceptionResolver.resolveException(request, response, null, ex);
+		assertNotNull("No ModelAndView returned", mav);
+		assertTrue("No Empty ModelAndView returned", mav.isEmpty());
+		assertEquals("Invalid status code", 400, response.getStatus());
+	}
+
+	@Test
+	public void statusCodeAndReason() {
+		StatusCodeAndReasonException ex = new StatusCodeAndReasonException();
+		ModelAndView mav = exceptionResolver.resolveException(request, response, null, ex);
+		assertNotNull("No ModelAndView returned", mav);
+		assertTrue("No Empty ModelAndView returned", mav.isEmpty());
+		assertEquals("Invalid status code", 410, response.getStatus());
+		assertEquals("Invalid status reason", "You suck!", response.getErrorMessage());
+	}
+
+	@Test
+	public void notAnnotated() {
+		Exception ex = new Exception();
+		exceptionResolver.resolveException(request, response, null, ex);
+		ModelAndView mav = exceptionResolver.resolveException(request, response, null, ex);
+		assertNull("ModelAndView returned", mav);
+	}
+
+	@ResponseStatus(HttpStatus.BAD_REQUEST)
+	private static class StatusCodeException extends Exception {
+
+	}
+
+	@ResponseStatus(value = HttpStatus.GONE, reason = "You suck!")
+	private static class StatusCodeAndReasonException extends Exception {
+
+	}
+}