SPR-5515: NPE when passing null as a request to RestTemplate.postForLocation

Author: poutsma

org.springframework.web/src/main/java/org/springframework/web/client/RestOperations.java

@@ -17,7 +17,6 @@
 package org.springframework.web.client;
 
 import java.net.URI;
-import java.util.EnumSet;
 import java.util.Map;
 import java.util.Set;
 
@@ -40,32 +39,30 @@ public interface RestOperations {
 	/**
 	 * Retrieve a representation by doing a GET on the specified URL.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param responseType the type of the return value
 	 * @param uriVariables the variables to expand the template
 	 * @return the converted object
 	 */
-	<T> T getForObject(String uri, Class<T> responseType, String... uriVariables)
-			throws RestClientException;
+	<T> T getForObject(String uri, Class<T> responseType, String... uriVariables) throws RestClientException;
 
 	/**
 	 * Retrieve a representation by doing a GET on the URI template.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param responseType the type of the return value
 	 * @param uriVariables the map containing variables for the URI template
 	 * @return the converted object
 	 */
-	<T> T getForObject(String uri, Class<T> responseType, Map<String, String> uriVariables)
-			throws RestClientException;
+	<T> T getForObject(String uri, Class<T> responseType, Map<String, String> uriVariables) throws RestClientException;
 
 
 	// HEAD
 
 	/**
 	 * Retrieve all headers of the resource specified by the URI template.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the variables to expand the template
 	 * @return all HTTP headers of that resource
 	 */
@@ -74,7 +71,7 @@ <T> T getForObject(String uri, Class<T> responseType, Map<String, String> uriVar
 	/**
 	 * Retrieve all headers of the resource specified by the URI template.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the map containing variables for the URI template
 	 * @return all HTTP headers of that resource
 	 */
@@ -84,45 +81,43 @@ <T> T getForObject(String uri, Class<T> responseType, Map<String, String> uriVar
 	// POST
 
 	/**
-	 * Create a new resource by POSTing the given object to the URI template. The value of the <code>Location</code>,
-	 * indicating where the new resource is stored, is returned.
+	 * Create a new resource by POSTing the given object to the URI template. The value of the <code>Location</code>
+	 * header, indicating where the new resource is stored, is returned.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
-	 * @param request the Object to be POSTED
+	 * @param uri	 the URI
+	 * @param request the Object to be POSTed, may be <code>null</code>
 	 * @return the value for the <code>Location</code> header
 	 */
-	URI postForLocation(String uri, Object request, String... uriVariables)
-			throws RestClientException;
+	URI postForLocation(String uri, Object request, String... uriVariables) throws RestClientException;
 
 	/**
-	 * Create a new resource by POSTing the given object to URI template. The value of the <code>Location</code>,
+	 * Create a new resource by POSTing the given object to URI template. The value of the <code>Location</code> header,
 	 * indicating where the new resource is stored, is returned.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
-	 * @param request the Object to be POSTed
+	 * @param uri		  the URI
+	 * @param request	  the Object to be POSTed, may be <code>null</code>
 	 * @param uriVariables the variables to expand the template
 	 * @return the value for the <code>Location</code> header
 	 */
-	URI postForLocation(String uri, Object request, Map<String, String> uriVariables)
-			throws RestClientException;
+	URI postForLocation(String uri, Object request, Map<String, String> uriVariables) throws RestClientException;
 
 
 	// PUT
 
 	/**
 	 * Create or update a resource by PUTting the given object to the URI.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
-	 * @param request the Object to be POSTed
+	 * @param uri		  the URI
+	 * @param request	  the Object to be PUT, may be <code>null</code>
 	 * @param uriVariables the variables to expand the template
 	 */
 	void put(String uri, Object request, String... uriVariables) throws RestClientException;
 
 	/**
 	 * Creates a new resource by PUTting the given object to URI template.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
-	 * @param request the Object to be POSTed
+	 * @param uri		  the URI
+	 * @param request	  the Object to be PUT, may be <code>null</code>
 	 * @param uriVariables the variables to expand the template
 	 */
 	void put(String uri, Object request, Map<String, String> uriVariables) throws RestClientException;
@@ -133,15 +128,15 @@ URI postForLocation(String uri, Object request, Map<String, String> uriVariables
 	/**
 	 * Delete the resources at the specified URI.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the variables to expand in the template
 	 */
 	void delete(String uri, String... uriVariables) throws RestClientException;
 
 	/**
 	 * Delete the resources at the specified URI.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the variables to expand the template
 	 */
 	void delete(String uri, Map<String, String> uriVariables) throws RestClientException;
@@ -152,22 +147,20 @@ URI postForLocation(String uri, Object request, Map<String, String> uriVariables
 	/**
 	 * Return the value of the Allow header for the given URI.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the variables to expand in the template
 	 * @return the value of the allow header
 	 */
-	Set<HttpMethod> optionsForAllow(String uri, String... uriVariables)
-			throws RestClientException;
+	Set<HttpMethod> optionsForAllow(String uri, String... uriVariables) throws RestClientException;
 
 	/**
 	 * Return the value of the Allow header for the given URI.
 	 * <p>URI Template variables are expanded using the given map.
-	 * @param uri the URI
+	 * @param uri		  the URI
 	 * @param uriVariables the variables to expand in the template
 	 * @return the value of the allow header
 	 */
-	Set<HttpMethod> optionsForAllow(String uri, Map<String, String> uriVariables)
-			throws RestClientException;
+	Set<HttpMethod> optionsForAllow(String uri, Map<String, String> uriVariables) throws RestClientException;
 
 
 	// general execution
@@ -176,30 +169,34 @@ Set<HttpMethod> optionsForAllow(String uri, Map<String, String> uriVariables)
 	 * Execute the HTTP methods to the given URI, preparing the request with the {@link RequestCallback},
 	 * and reading the response with a {@link ResponseExtractor}.
 	 * <p>URI Template variables are expanded using the given URI variables, if any.
-	 * @param uri the URI
-	 * @param method the HTTP method (GET, POST, etc)
-	 * @param requestCallback object that prepares the request
+	 * @param uri			   the URI
+	 * @param method			the HTTP method (GET, POST, etc)
+	 * @param requestCallback   object that prepares the request
 	 * @param responseExtractor object that extracts the return value from the response
-	 * @param uriVariables the variables to expand in the template
+	 * @param uriVariables	  the variables to expand in the template
 	 * @return an arbitrary object, as returned by the {@link ResponseExtractor}
 	 */
-	<T> T execute(String uri, HttpMethod method, RequestCallback requestCallback,
-			ResponseExtractor<T> responseExtractor, String... uriVariables)
-			throws RestClientException;
+	<T> T execute(String uri,
+			HttpMethod method,
+			RequestCallback requestCallback,
+			ResponseExtractor<T> responseExtractor,
+			String... uriVariables) throws RestClientException;
 
 	/**
 	 * Execute the HTTP methods to the given URI, preparing the request with the {@link RequestCallback},
 	 * and reading the response with a {@link ResponseExtractor}.
 	 * <p>URI Template variables are expanded using the given URI variables map.
-	 * @param uri the URI
-	 * @param method the HTTP method (GET, POST, etc)
-	 * @param requestCallback object that prepares the request
+	 * @param uri			   the URI
+	 * @param method			the HTTP method (GET, POST, etc)
+	 * @param requestCallback   object that prepares the request
 	 * @param responseExtractor object that extracts the return value from the response
-	 * @param uriVariablesthe variables to expand in the template
+	 * @param uriVariables	  the variables to expand in the template
 	 * @return an arbitrary object, as returned by the {@link ResponseExtractor}
 	 */
-	<T> T execute(String uri, HttpMethod method, RequestCallback requestCallback,
-			ResponseExtractor<T> responseExtractor, Map<String, String> uriVariables)
-			throws RestClientException;
+	<T> T execute(String uri,
+			HttpMethod method,
+			RequestCallback requestCallback,
+			ResponseExtractor<T> responseExtractor,
+			Map<String, String> uriVariables) throws RestClientException;
 
 }

org.springframework.web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -91,14 +91,13 @@ public class RestTemplate extends HttpAccessor implements RestOperations {
 	private final ResponseExtractor<HttpHeaders> headersExtractor = new HeadersExtractor();
 
 	private HttpMessageConverter<?>[] messageConverters =
-			new HttpMessageConverter[] {new ByteArrayHttpMessageConverter(), new StringHttpMessageConverter()};
+			new HttpMessageConverter[]{new ByteArrayHttpMessageConverter(), new StringHttpMessageConverter()};
 
 	private ResponseErrorHandler errorHandler = new DefaultResponseErrorHandler();
 
 
 	/**
 	 * Create a new instance of the {@link RestTemplate} using default settings.
-	 * @see #initDefaultStrategies()
 	 */
 	public RestTemplate() {
 	}
@@ -166,8 +165,7 @@ public ResponseErrorHandler getErrorHandler() {
 
 	// GET
 
-	public <T> T getForObject(String url, Class<T> responseType, String... urlVariables)
-			throws RestClientException {
+	public <T> T getForObject(String url, Class<T> responseType, String... urlVariables) throws RestClientException {
 
 		checkForSupportedMessageConverter(responseType);
 		return execute(url, HttpMethod.GET, new GetCallback<T>(responseType),
@@ -196,19 +194,20 @@ public HttpHeaders headForHeaders(String url, Map<String, String> urlVariables)
 
 	// POST
 
-	public URI postForLocation(String url, Object request, String... urlVariables)
-			throws RestClientException {
-
-		checkForSupportedMessageConverter(request.getClass());
+	public URI postForLocation(String url, Object request, String... urlVariables) throws RestClientException {
+		if (request != null) {
+			checkForSupportedMessageConverter(request.getClass());
+		}
 		HttpHeaders headers =
 				execute(url, HttpMethod.POST, new PostPutCallback(request), this.headersExtractor, urlVariables);
 		return headers.getLocation();
 	}
 
 	public URI postForLocation(String url, Object request, Map<String, String> urlVariables)
 			throws RestClientException {
-
-		checkForSupportedMessageConverter(request.getClass());
+		if (request != null) {
+			checkForSupportedMessageConverter(request.getClass());
+		}
 		HttpHeaders headers =
 				execute(url, HttpMethod.POST, new PostPutCallback(request), this.headersExtractor, urlVariables);
 		return headers.getLocation();
@@ -218,12 +217,16 @@ public URI postForLocation(String url, Object request, Map<String, String> urlVa
 	// PUT
 
 	public void put(String url, Object request, String... urlVariables) throws RestClientException {
-		checkForSupportedMessageConverter(request.getClass());
+		if (request != null) {
+			checkForSupportedMessageConverter(request.getClass());
+		}
 		execute(url, HttpMethod.PUT, new PostPutCallback(request), null, urlVariables);
 	}
 
 	public void put(String url, Object request, Map<String, String> urlVariables) throws RestClientException {
-		checkForSupportedMessageConverter(request.getClass());
+		if (request != null) {
+			checkForSupportedMessageConverter(request.getClass());
+		}
 		execute(url, HttpMethod.PUT, new PostPutCallback(request), null, urlVariables);
 	}
 
@@ -241,15 +244,13 @@ public void delete(String url, Map<String, String> urlVariables) throws RestClie
 
 	// OPTIONS
 
-	public Set<HttpMethod> optionsForAllow(String url, String... urlVariables)
-			throws RestClientException {
+	public Set<HttpMethod> optionsForAllow(String url, String... urlVariables) throws RestClientException {
 
 		HttpHeaders headers = execute(url, HttpMethod.OPTIONS, null, this.headersExtractor, urlVariables);
 		return headers.getAllow();
 	}
 
-	public Set<HttpMethod> optionsForAllow(String url, Map<String, String> urlVariables)
-			throws RestClientException {
+	public Set<HttpMethod> optionsForAllow(String url, Map<String, String> urlVariables) throws RestClientException {
 
 		HttpHeaders headers = execute(url, HttpMethod.OPTIONS, null, this.headersExtractor, urlVariables);
 		return headers.getAllow();
@@ -258,18 +259,22 @@ public Set<HttpMethod> optionsForAllow(String url, Map<String, String> urlVariab
 
 	// general execution
 
-	public <T> T execute(String url, HttpMethod method, RequestCallback requestCallback,
-			ResponseExtractor<T> responseExtractor, String... urlVariables)
-			throws RestClientException {
+	public <T> T execute(String url,
+			HttpMethod method,
+			RequestCallback requestCallback,
+			ResponseExtractor<T> responseExtractor,
+			String... urlVariables) throws RestClientException {
 
 		UriTemplate uriTemplate = new UriTemplate(url);
 		URI expanded = uriTemplate.expand(urlVariables);
 		return doExecute(expanded, method, requestCallback, responseExtractor);
 	}
 
-	public <T> T execute(String url,HttpMethod method, RequestCallback requestCallback,
-			ResponseExtractor<T> responseExtractor, Map<String, String> urlVariables)
-			throws RestClientException {
+	public <T> T execute(String url,
+			HttpMethod method,
+			RequestCallback requestCallback,
+			ResponseExtractor<T> responseExtractor,
+			Map<String, String> urlVariables) throws RestClientException {
 
 		UriTemplate uriTemplate = new UriTemplate(url);
 		URI expanded = uriTemplate.expand(urlVariables);
@@ -279,13 +284,15 @@ public <T> T execute(String url,HttpMethod method, RequestCallback requestCallba
 	/**
 	 * Execute the given method on the provided URI. The {@link ClientHttpRequest} is processed using the {@link
 	 * RequestCallback}; the response with the {@link ResponseExtractor}.
-	 * @param url the fully-expanded URL to connect to
-	 * @param method the HTTP method to execute (GET, POST, etc.)
-	 * @param requestCallback object that prepares the request (can be <code>null</code>)
+	 * @param url			   the fully-expanded URL to connect to
+	 * @param method			the HTTP method to execute (GET, POST, etc.)
+	 * @param requestCallback   object that prepares the request (can be <code>null</code>)
 	 * @param responseExtractor object that extracts the return value from the response (can be <code>null</code>)
 	 * @return an arbitrary object, as returned by the {@link ResponseExtractor}
 	 */
-	protected <T> T doExecute(URI url, HttpMethod method, RequestCallback requestCallback,
+	protected <T> T doExecute(URI url,
+			HttpMethod method,
+			RequestCallback requestCallback,
 			ResponseExtractor<T> responseExtractor) throws RestClientException {
 
 		Assert.notNull(url, "'url' must not be null");
@@ -376,12 +383,16 @@ private PostPutCallback(Object request) {
 
 		@SuppressWarnings("unchecked")
 		public void doWithRequest(ClientHttpRequest httpRequest) throws IOException {
-			HttpMessageConverter entityConverter = getSupportedMessageConverters(this.request.getClass()).get(0);
-			entityConverter.write(this.request, httpRequest);
+			if (request != null) {
+				HttpMessageConverter entityConverter = getSupportedMessageConverters(this.request.getClass()).get(0);
+				entityConverter.write(this.request, httpRequest);
+			}
+			else {
+				httpRequest.getHeaders().setContentLength(0L);
+			}
 		}
 	}
 
-
 	/**
 	 * Response extractor that uses the registered {@linkplain HttpMessageConverter entity converters}
 	 * to convert the response into a type <code>T</code>.