Missing path variable is now a 500 error

Before this change a missing path variable value resulted in a 400
error where in fact the error is due to a mismatch between the
declared @PathVariable and the URI template, i.e. a 500 error.

This change introduced a MissingPathVariableException as a sub-class
of ServletRequestBindingException (the exception previously thrown)
and results in a response status code of 500 by default.

Issue: SPR-13121

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/PathVariableMethodArgumentResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import static org.junit.Assert.*;
+
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.Map;
@@ -26,15 +28,13 @@ import org.junit.Test;
 import org.springframework.core.MethodParameter;
 import org.springframework.mock.web.test.MockHttpServletRequest;
 import org.springframework.mock.web.test.MockHttpServletResponse;
-import org.springframework.web.bind.ServletRequestBindingException;
+import org.springframework.web.bind.MissingPathVariableException;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.servlet.HandlerMapping;
 import org.springframework.web.servlet.View;
 
-import static org.junit.Assert.*;
-
 /**
  * Test fixture with {@link PathVariableMethodArgumentResolver}.
  *
@@ -96,7 +96,7 @@ public class PathVariableMethodArgumentResolverTests {
 		uriTemplateVars.put("name", "value");
 		request.setAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVars);
 
-		Map<String, Object> pathVars = new HashMap<String, Object>();
+		Map<String, Object> pathVars;
 		uriTemplateVars.put("oldName", "oldValue");
 		request.setAttribute(View.PATH_VARIABLES, uriTemplateVars);
 
@@ -110,12 +110,13 @@ public class PathVariableMethodArgumentResolverTests {
 		assertEquals("oldValue", pathVars.get("oldName"));
 	}
 
-	@Test(expected = ServletRequestBindingException.class)
+	@Test(expected = MissingPathVariableException.class)
 	public void handleMissingValue() throws Exception {
 		resolver.resolveArgument(paramNamedString, mavContainer, webRequest, null);
 		fail("Unresolved path variable should lead to exception.");
 	}
 
+	@SuppressWarnings("unused")
 	public void handle(@PathVariable(value = "name") String param1, String param2) {
 	}
 

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ResponseEntityExceptionHandlerTests.java

@@ -26,6 +26,7 @@ import org.junit.Test;
 
 import org.springframework.beans.ConversionNotSupportedException;
 import org.springframework.beans.TypeMismatchException;
+import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
@@ -41,6 +42,7 @@ import org.springframework.web.HttpMediaTypeNotAcceptableException;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
 import org.springframework.web.HttpRequestMethodNotSupportedException;
 import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.MissingPathVariableException;
 import org.springframework.web.bind.MissingServletRequestParameterException;
 import org.springframework.web.bind.ServletRequestBindingException;
 import org.springframework.web.bind.annotation.ControllerAdvice;
@@ -86,15 +88,16 @@ public class ResponseEntityExceptionHandlerTests {
 	@Test
 	public void supportsAllDefaultHandlerExceptionResolverExceptionTypes() throws Exception {
 
-		Method annotMethod = ResponseEntityExceptionHandler.class.getMethod("handleException", Exception.class, WebRequest.class);
-		ExceptionHandler annot = annotMethod.getAnnotation(ExceptionHandler.class);
-		List<Class<? extends Throwable>> supportedTypes = Arrays.asList(annot.value());
+		Class<ResponseEntityExceptionHandler> clazz = ResponseEntityExceptionHandler.class;
+		Method handleExceptionMethod = clazz.getMethod("handleException", Exception.class, WebRequest.class);
+		ExceptionHandler annotation = handleExceptionMethod.getAnnotation(ExceptionHandler.class);
+		List<Class<?>> exceptionTypes = Arrays.asList(annotation.value());
 
 		for (Method method : DefaultHandlerExceptionResolver.class.getDeclaredMethods()) {
 			Class<?>[] paramTypes = method.getParameterTypes();
 			if (method.getName().startsWith("handle") && (paramTypes.length == 4)) {
 				String name = paramTypes[0].getSimpleName();
-				assertTrue("@ExceptionHandler is missing " + name, supportedTypes.contains(paramTypes[0]));
+				assertTrue("@ExceptionHandler is missing " + name, exceptionTypes.contains(paramTypes[0]));
 			}
 		}
 	}
@@ -130,6 +133,14 @@ public class ResponseEntityExceptionHandlerTests {
 		testException(ex);
 	}
 
+	@Test
+	public void missingPathVariable() throws NoSuchMethodException {
+		Method method = getClass().getDeclaredMethod("handle", String.class);
+		MethodParameter parameter = new MethodParameter(method, 0);
+		Exception ex = new MissingPathVariableException("param", parameter);
+		testException(ex);
+	}
+
 	@Test
 	public void missingServletRequestParameter() {
 		Exception ex = new MissingServletRequestParameterException("param", "type");
@@ -241,8 +252,10 @@ public class ResponseEntityExceptionHandlerTests {
 			headers.set("someHeader", "someHeaderValue");
 			return handleExceptionInternal(ex, "error content", headers, status, request);
 		}
+	}
 
-
+	@SuppressWarnings("unused")
+	void handle(String arg) {
 	}
 
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/support/DefaultHandlerExceptionResolverTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.web.servlet.mvc.support;
 
+import java.lang.reflect.Method;
 import java.util.Collections;
 
 import org.junit.Before;
@@ -36,6 +37,7 @@ import org.springframework.validation.BindException;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
 import org.springframework.web.HttpRequestMethodNotSupportedException;
 import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.MissingPathVariableException;
 import org.springframework.web.bind.MissingServletRequestParameterException;
 import org.springframework.web.bind.ServletRequestBindingException;
 import org.springframework.web.multipart.support.MissingServletRequestPartException;
@@ -93,6 +95,19 @@ public class DefaultHandlerExceptionResolverTests {
 		assertEquals("Invalid Accept header", "application/pdf", response.getHeader("Accept"));
 	}
 
+	@Test
+	public void handleMissingPathVariable() throws NoSuchMethodException {
+		Method method = getClass().getMethod("handle", String.class);
+		MethodParameter parameter = new MethodParameter(method, 0);
+		MissingPathVariableException ex = new MissingPathVariableException("foo", parameter);
+		ModelAndView mav = exceptionResolver.resolveException(request, response, null, ex);
+		assertNotNull("No ModelAndView returned", mav);
+		assertTrue("No Empty ModelAndView returned", mav.isEmpty());
+		assertEquals("Invalid status code", 500, response.getStatus());
+		assertEquals("Missing URI template variable 'foo' for method parameter of type String",
+				response.getErrorMessage());
+	}
+
 	@Test
 	public void handleMissingServletRequestParameter() {
 		MissingServletRequestParameterException ex = new MissingServletRequestParameterException("foo", "bar");
@@ -196,6 +211,7 @@ public class DefaultHandlerExceptionResolverTests {
 		assertSame(ex, request.getAttribute("javax.servlet.error.exception"));
 	}
 
+	@SuppressWarnings("unused")
 	public void handle(String arg) {
 	}