DATAREST-217 - Significant overhaul of HTTP method support detection.

Refactored the way the general support for an HTTP method for the resource exported. The decision is implemented in RootResourceInformation (formerly RepositoryRestRequest). Removed request specific information from that class and introduced a HandlerMethodArgumentResolver to be able to inject HttpMethod instance into controller methods (filed https://jira.springsource.org/browse/SPR-11425 to get that support into Spring Framework itself).

Generally moved away from throwing NoSuchMethodExceptions and correctly expose HttpRequestMethodNotSupportedException instead to make sure Spring MVC renders the appropriate allowed methods if possible.

Removed RepositoryInvokerHandlerMethodArgumentResolver as a RepositoryInvoker can be obtained from the RootResourceInformation where necessary.

Related pull request: spring-projects#125.

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/invoke/ReflectionRepositoryInvoker.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 the original author or authors.
+ * Copyright 2013-2014 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.
@@ -72,6 +72,15 @@ public ReflectionRepositoryInvoker(Object repository, RepositoryInformation info
 		this.conversionService = conversionService;
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#hasFindAllMethod()
+	 */
+	@Override
+	public boolean hasFindAllMethod() {
+		return methods.hasFindAllMethod();
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#exposesFindAll()
@@ -115,6 +124,15 @@ public Iterable<Object> invokeFindAll(Pageable pageable) {
 		return invoke(method, pageable);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#hasSaveMethod()
+	 */
+	@Override
+	public boolean hasSaveMethod() {
+		return methods.hasSaveMethod();
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#exposesSave()
@@ -132,6 +150,15 @@ public <T> T invokeSave(T object) {
 		return invoke(methods.getSaveMethod(), object);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#hasFindOneMethod()
+	 */
+	@Override
+	public boolean hasFindOneMethod() {
+		return methods.hasFindOneMethod();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#exposesFindOne()
@@ -150,6 +177,15 @@ public <T> T invokeFindOne(Serializable id) {
 		return invoke(methods.getFindOneMethod(), convertId(id));
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#hasDeleteMethod()
+	 */
+	@Override
+	public boolean hasDeleteMethod() {
+		return methods.hasDelete();
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.invoke.RepositoryInvocationInformation#exposesDelete()

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/invoke/RepositoryInvocationInformation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 the original author or authors.
+ * Copyright 2013-2014 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.
@@ -22,11 +22,59 @@
  */
 public interface RepositoryInvocationInformation {
 
+	/**
+	 * Returns whether the repository has a method to save objects.
+	 * 
+	 * @return
+	 */
+	boolean hasSaveMethod();
+
+	/**
+	 * Returns whether the repository exposes the save method.
+	 * 
+	 * @return
+	 */
 	boolean exposesSave();
 
+	/**
+	 * Returns whether the repository has a method to delete objects.
+	 * 
+	 * @return
+	 */
+	boolean hasDeleteMethod();
+
+	/**
+	 * Returns whether the repository exposes the delete method.
+	 * 
+	 * @return
+	 */
 	boolean exposesDelete();
 
+	/**
+	 * Returns whether the repository has a method to find a single object.
+	 * 
+	 * @return
+	 */
+	boolean hasFindOneMethod();
+
+	/**
+	 * Returns whether the repository exposes the method to find a single object.
+	 * 
+	 * @return
+	 */
 	boolean exposesFindOne();
 
+	/**
+	 * Returns whether the repository has a method to find all objects.
+	 * 
+	 * @return
+	 */
+	boolean hasFindAllMethod();
+
+	/**
+	 * Returns whether the repository exposes the method to find all objects.
+	 * 
+	 * @return
+	 */
 	boolean exposesFindAll();
 }

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/AbstractRepositoryRestController.java

@@ -43,6 +43,7 @@
 import org.springframework.hateoas.Resource;
 import org.springframework.hateoas.Resources;
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.HttpMessageNotReadableException;
@@ -108,12 +109,6 @@ public ResponseEntity<?> handleNotFound() {
 		return notFound();
 	}
 
-	@ExceptionHandler({ NoSuchMethodError.class, HttpRequestMethodNotSupportedException.class })
-	@ResponseBody
-	public ResponseEntity<?> handleNoSuchMethod() {
-		return errorResponse(null, HttpStatus.METHOD_NOT_ALLOWED);
-	}
-
 	@ExceptionHandler({ HttpMessageNotReadableException.class, HttpMessageNotWritableException.class })
 	@ResponseBody
 	public ResponseEntity<ExceptionMessage> handleNotReadable(HttpMessageNotReadableException e) {
@@ -157,6 +152,22 @@ public ResponseEntity handleConflict(Exception ex) {
 		return errorResponse(null, ex, HttpStatus.CONFLICT);
 	}
 
+	/**
+	 * Send {@code 405 Method Not Allowed} and include the supported {@link HttpMethod}s in the {@code Allow} header.
+	 * 
+	 * @param o_O
+	 * @return
+	 */
+	@ExceptionHandler
+	@ResponseBody
+	public ResponseEntity<Void> handle(HttpRequestMethodNotSupportedException o_O) {
+
+		HttpHeaders headers = new HttpHeaders();
+		headers.setAllow(o_O.getSupportedHttpMethods());
+
+		return new ResponseEntity<Void>(headers, HttpStatus.METHOD_NOT_ALLOWED);
+	}
+
 	protected <T> ResponseEntity<T> notFound() {
 		return notFound(null, null);
 	}
@@ -195,9 +206,9 @@ public <T> ResponseEntity<T> response(HttpHeaders headers, T body, HttpStatus st
 		return new ResponseEntity<T>(body, hdrs, status);
 	}
 
-	protected Link resourceLink(RepositoryRestRequest repoRequest, Resource resource) {
+	protected Link resourceLink(RootResourceInformation resourceLink, Resource resource) {
 
-		ResourceMetadata repoMapping = repoRequest.getResourceMetadata();
+		ResourceMetadata repoMapping = resourceLink.getResourceMetadata();
 
 		Link selfLink = resource.getLink("self");
 		String rel = repoMapping.getItemResourceRel();

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/PersistentEntityResourceHandlerMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -41,21 +41,22 @@ public class PersistentEntityResourceHandlerMethodArgumentResolver implements Ha
 	private static final String ERROR_MESSAGE = "Could not read an object of type %s from the request! Converter %s returned null!";
 	private static final String NO_CONVERTER_FOUND = "No suitable HttpMessageConverter found to read request body into object of type %s from request with content type of %s!";
 
-	private final RepositoryRestRequestHandlerMethodArgumentResolver repoRequestResolver;
+	private final RootResourceInformationHandlerMethodArgumentResolver repoRequestResolver;
 	private final List<HttpMessageConverter<?>> messageConverters;
 
 	/**
 	 * Creates a new {@link PersistentEntityResourceHandlerMethodArgumentResolver} for the given
-	 * {@link HttpMessageConverter}s and {@link RepositoryRestRequestHandlerMethodArgumentResolver}..
+	 * {@link HttpMessageConverter}s and {@link RootResourceInformationHandlerMethodArgumentResolver}..
 	 * 
 	 * @param messageConverters must not be {@literal null}.
 	 * @param repositoryRequestResolver must not be {@literal null}.
 	 */
 	public PersistentEntityResourceHandlerMethodArgumentResolver(List<HttpMessageConverter<?>> messageConverters,
-			RepositoryRestRequestHandlerMethodArgumentResolver repositoryRequestResolver) {
+			RootResourceInformationHandlerMethodArgumentResolver repositoryRequestResolver) {
 
 		Assert.notEmpty(messageConverters, "MessageConverters must not be null or empty!");
-		Assert.notNull(repositoryRequestResolver, "RepositoryRestRequestHandlerMethodArgumentResolver must not be empty!");
+		Assert
+				.notNull(repositoryRequestResolver, "RootResourceInformationHandlerMethodArgumentResolver must not be empty!");
 
 		this.messageConverters = messageConverters;
 		this.repoRequestResolver = repositoryRequestResolver;
@@ -78,13 +79,14 @@ public boolean supportsParameter(MethodParameter parameter) {
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
 			NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
-		RepositoryRestRequest repoRequest = (RepositoryRestRequest) repoRequestResolver.resolveArgument(parameter,
-				mavContainer, webRequest, binderFactory);
+
+		RootResourceInformation resourceInformation = repoRequestResolver.resolveArgument(parameter, mavContainer,
+				webRequest, binderFactory);
 
 		HttpServletRequest nativeRequest = webRequest.getNativeRequest(HttpServletRequest.class);
 		ServletServerHttpRequest request = new ServletServerHttpRequest(nativeRequest);
 
-		Class<?> domainType = repoRequest.getPersistentEntity().getType();
+		Class<?> domainType = resourceInformation.getPersistentEntity().getType();
 		MediaType contentType = request.getHeaders().getContentType();
 
 		for (HttpMessageConverter converter : messageConverters) {
@@ -99,7 +101,7 @@ public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer m
 				throw new HttpMessageNotReadableException(String.format(ERROR_MESSAGE, domainType, converter));
 			}
 
-			return new PersistentEntityResource<Object>(repoRequest.getPersistentEntity(), obj);
+			return new PersistentEntityResource<Object>(resourceInformation.getPersistentEntity(), obj);
 		}
 
 		throw new HttpMessageNotReadableException(String.format(NO_CONVERTER_FOUND, domainType, contentType));