Revise nullability in HttpEntity and ResponseEntity

framework-docs/src/main/kotlin/org/springframework/docs/web/webmvc/mvccontroller/mvcannexceptionhandlerexc/ExceptionController.kt

@@ -27,15 +27,15 @@ class ExceptionController {
 
 	// tag::narrow[]
 	@ExceptionHandler(FileSystemException::class, RemoteException::class)
-	fun handleIoException(ex: IOException): ResponseEntity<String> {
+	fun handleIoException(ex: IOException): ResponseEntity<String?> {
 		return ResponseEntity.internalServerError().body(ex.message)
 	}
 	// end::narrow[]
 
 
 	// tag::general[]
 	@ExceptionHandler(FileSystemException::class, RemoteException::class)
-	fun handleExceptions(ex: Exception): ResponseEntity<String> {
+	fun handleExceptions(ex: Exception): ResponseEntity<String?> {
 		return ResponseEntity.internalServerError().body(ex.message)
 	}
 	// end::general[]

spring-web/src/main/java/org/springframework/http/HttpEntity.java

@@ -56,7 +56,7 @@
  * @see #getBody()
  * @see #getHeaders()
  */
-public class HttpEntity<T> {
+public class HttpEntity<T extends @Nullable Object> {
 
 	/**
 	 * An {@code HttpEntity} instance with a {@code null} body and
@@ -67,12 +67,13 @@ public class HttpEntity<T> {
 
 	private final HttpHeaders headers;
 
-	private final @Nullable T body;
+	private final T body;
 
 
 	/**
 	 * Create a new, empty {@code HttpEntity}.
 	 */
+	@SuppressWarnings("NullAway")
 	protected HttpEntity() {
 		this(null, (HttpHeaders) null);
 	}
@@ -90,6 +91,7 @@ public HttpEntity(T body) {
 	 * @param headers the entity headers
 	 * @since 7.0
 	 */
+	@SuppressWarnings("NullAway")
 	public HttpEntity(HttpHeaders headers) {
 		this(null, headers);
 	}
@@ -100,7 +102,7 @@ public HttpEntity(HttpHeaders headers) {
 	 * @param headers the entity headers
 	 * @since 7.0
 	 */
-	public HttpEntity(@Nullable T body, @Nullable HttpHeaders headers) {
+	public HttpEntity(T body, @Nullable HttpHeaders headers) {
 		this.body = body;
 		this.headers = (headers != null) ? headers : new HttpHeaders();
 	}
@@ -110,6 +112,7 @@ public HttpEntity(@Nullable T body, @Nullable HttpHeaders headers) {
 	 * @param headers the entity headers
 	 * @deprecated in favor of {@link #HttpEntity(HttpHeaders)}
 	 */
+	@SuppressWarnings("NullAway")
 	@Deprecated(since = "7.0", forRemoval = true)
 	public HttpEntity(MultiValueMap<String, String> headers) {
 		this(null, headers);
@@ -122,7 +125,7 @@ public HttpEntity(MultiValueMap<String, String> headers) {
 	 * @deprecated in favor of {@link #HttpEntity(Object, HttpHeaders)}
 	 */
 	@Deprecated(since = "7.0", forRemoval = true)
-	public HttpEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers) {
+	public HttpEntity(T body, @Nullable MultiValueMap<String, String> headers) {
 		this(body, (headers != null) ? new HttpHeaders(headers) : new HttpHeaders());
 	}
 
@@ -137,7 +140,7 @@ public HttpHeaders getHeaders() {
 	/**
 	 * Returns the body of this entity.
 	 */
-	public @Nullable T getBody() {
+	public T getBody() {
 		return this.body;
 	}
 

spring-web/src/main/java/org/springframework/http/RequestEntity.java

@@ -65,7 +65,7 @@
  * @see org.springframework.web.client.RestOperations#exchange(RequestEntity, Class)
  * @see ResponseEntity
  */
-public class RequestEntity<T> extends HttpEntity<T> {
+public class RequestEntity<T extends @Nullable Object> extends HttpEntity<T> {
 
 	private final @Nullable HttpMethod method;
 
@@ -78,6 +78,7 @@ public class RequestEntity<T> extends HttpEntity<T> {
 	 * @param method the method
 	 * @param url the URL
 	 */
+	@SuppressWarnings("NullAway")
 	public RequestEntity(HttpMethod method, URI url) {
 		this(null, (HttpHeaders) null, method, url, null);
 	}
@@ -88,7 +89,7 @@ public RequestEntity(HttpMethod method, URI url) {
 	 * @param method the method
 	 * @param url the URL
 	 */
-	public RequestEntity(@Nullable T body, HttpMethod method, URI url) {
+	public RequestEntity(T body, HttpMethod method, URI url) {
 		this(body, (HttpHeaders) null, method, url, null);
 	}
 
@@ -100,7 +101,7 @@ public RequestEntity(@Nullable T body, HttpMethod method, URI url) {
 	 * @param type the type used for generic type resolution
 	 * @since 4.3
 	 */
-	public RequestEntity(@Nullable T body, HttpMethod method, URI url, Type type) {
+	public RequestEntity(T body, HttpMethod method, URI url, Type type) {
 		this(body, (HttpHeaders) null, method, url, type);
 	}
 
@@ -111,6 +112,7 @@ public RequestEntity(@Nullable T body, HttpMethod method, URI url, Type type) {
 	 * @param url the URL
 	 * @since 7.0
 	 */
+	@SuppressWarnings("NullAway")
 	public RequestEntity(HttpHeaders headers, HttpMethod method, URI url) {
 		this(null, headers, method, url, null);
 	}
@@ -123,7 +125,7 @@ public RequestEntity(HttpHeaders headers, HttpMethod method, URI url) {
 	 * @param url the URL
 	 * @since 7.0
 	 */
-	public RequestEntity(@Nullable T body, @Nullable HttpHeaders headers,
+	public RequestEntity(T body, @Nullable HttpHeaders headers,
 			@Nullable HttpMethod method, URI url) {
 
 		this(body, headers, method, url, null);
@@ -138,7 +140,7 @@ public RequestEntity(@Nullable T body, @Nullable HttpHeaders headers,
 	 * @param type the type used for generic type resolution
 	 * @since 7.0
 	 */
-	public RequestEntity(@Nullable T body, @Nullable HttpHeaders headers,
+	public RequestEntity(T body, @Nullable HttpHeaders headers,
 			@Nullable HttpMethod method, @Nullable URI url, @Nullable Type type) {
 
 		super(body, headers);
@@ -154,6 +156,7 @@ public RequestEntity(@Nullable T body, @Nullable HttpHeaders headers,
 	 * @param url the URL
 	 * @deprecated in favor of {@link #RequestEntity(HttpHeaders, HttpMethod, URI)}
 	 */
+	@SuppressWarnings("NullAway")
 	@Deprecated(since = "7.0", forRemoval = true)
 	public RequestEntity(MultiValueMap<String, String> headers, HttpMethod method, URI url) {
 		this(null, headers, method, url, null);
@@ -169,7 +172,7 @@ public RequestEntity(MultiValueMap<String, String> headers, HttpMethod method, U
 	 */
 	@Deprecated(since = "7.0", forRemoval = true)
 	public RequestEntity(
-			@Nullable T body, @Nullable MultiValueMap<String, String> headers,
+			T body, @Nullable MultiValueMap<String, String> headers,
 			@Nullable HttpMethod method, URI url) {
 
 		this(body, headers, method, url, null);
@@ -187,7 +190,7 @@ public RequestEntity(
 	 */
 	@SuppressWarnings("removal")
 	@Deprecated(since = "7.0", forRemoval = true)
-	public RequestEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers,
+	public RequestEntity(T body, @Nullable MultiValueMap<String, String> headers,
 			@Nullable HttpMethod method, @Nullable URI url, @Nullable Type type) {
 
 		super(body, headers);
@@ -546,7 +549,7 @@ public interface HeadersBuilder<B extends HeadersBuilder<B>> {
 		 * @return the request entity
 		 * @see BodyBuilder#body(Object)
 		 */
-		RequestEntity<Void> build();
+		RequestEntity<@Nullable Void> build();
 	}
 
 
@@ -702,7 +705,7 @@ public BodyBuilder ifNoneMatch(String... ifNoneMatches) {
 		}
 
 		@Override
-		public RequestEntity<Void> build() {
+		public RequestEntity<@Nullable Void> build() {
 			return buildInternal(null, null);
 		}
 
@@ -716,7 +719,7 @@ public <T> RequestEntity<T> body(T body, Type type) {
 			return buildInternal(body, type);
 		}
 
-		private <T> RequestEntity<T> buildInternal(@Nullable T body, @Nullable Type type) {
+		private <T extends @Nullable Object> RequestEntity<T> buildInternal(T body, @Nullable Type type) {
 			if (this.uri != null) {
 				return new RequestEntity<>(body, this.headers, this.method, this.uri, type);
 			}
@@ -736,7 +739,7 @@ else if (this.uriTemplate != null){
 	 * @since 5.3
 	 * @param <T> the body type
 	 */
-	public static class UriTemplateRequestEntity<T> extends RequestEntity<T> {
+	public static class UriTemplateRequestEntity<T extends @Nullable Object> extends RequestEntity<T> {
 
 		private final String uriTemplate;
 
@@ -745,7 +748,7 @@ public static class UriTemplateRequestEntity<T> extends RequestEntity<T> {
 		private final @Nullable Map<String, ? extends @Nullable Object> uriVarsMap;
 
 		UriTemplateRequestEntity(
-				@Nullable T body, @Nullable HttpHeaders headers,
+				T body, @Nullable HttpHeaders headers,
 				@Nullable HttpMethod method, @Nullable Type type, String uriTemplate,
 				@Nullable Object @Nullable [] uriVarsArray, @Nullable Map<String, ?> uriVarsMap) {
 

spring-web/src/main/java/org/springframework/http/ResponseEntity.java

@@ -78,7 +78,7 @@
  * @see org.springframework.web.client.RestOperations#getForEntity(URI, Class)
  * @see RequestEntity
  */
-public class ResponseEntity<T> extends HttpEntity<T> {
+public class ResponseEntity<T extends @Nullable Object> extends HttpEntity<T> {
 
 	private final HttpStatusCode status;
 
@@ -87,6 +87,7 @@ public class ResponseEntity<T> extends HttpEntity<T> {
 	 * Create a {@code ResponseEntity} with a status code only.
 	 * @param status the status code
 	 */
+	@SuppressWarnings("NullAway")
 	public ResponseEntity(HttpStatusCode status) {
 		this(null, (HttpHeaders) null, status);
 	}
@@ -96,7 +97,7 @@ public ResponseEntity(HttpStatusCode status) {
 	 * @param body the entity body
 	 * @param status the status code
 	 */
-	public ResponseEntity(@Nullable T body, HttpStatusCode status) {
+	public ResponseEntity(T body, HttpStatusCode status) {
 		this(body, (HttpHeaders) null, status);
 	}
 
@@ -106,6 +107,7 @@ public ResponseEntity(@Nullable T body, HttpStatusCode status) {
 	 * @param status the status code
 	 * @since 7.0
 	 */
+	@SuppressWarnings("NullAway")
 	public ResponseEntity(HttpHeaders headers, HttpStatusCode status) {
 		this(null, headers, status);
 	}
@@ -117,7 +119,7 @@ public ResponseEntity(HttpHeaders headers, HttpStatusCode status) {
 	 * @param rawStatus the status code value
 	 * @since 7.0
 	 */
-	public ResponseEntity(@Nullable T body, @Nullable HttpHeaders headers, int rawStatus) {
+	public ResponseEntity(T body, @Nullable HttpHeaders headers, int rawStatus) {
 		this(body, headers, HttpStatusCode.valueOf(rawStatus));
 	}
 
@@ -128,7 +130,7 @@ public ResponseEntity(@Nullable T body, @Nullable HttpHeaders headers, int rawSt
 	 * @param statusCode the status code
 	 * @since 7.0
 	 */
-	public ResponseEntity(@Nullable T body, @Nullable HttpHeaders headers, HttpStatusCode statusCode) {
+	public ResponseEntity(T body, @Nullable HttpHeaders headers, HttpStatusCode statusCode) {
 		super(body, headers);
 		Assert.notNull(statusCode, "HttpStatusCode must not be null");
 
@@ -141,6 +143,7 @@ public ResponseEntity(@Nullable T body, @Nullable HttpHeaders headers, HttpStatu
 	 * @param status the status code
 	 * @deprecated in favor of {@link #ResponseEntity(HttpHeaders, HttpStatusCode)}
 	 */
+	@SuppressWarnings("NullAway")
 	@Deprecated(since = "7.0", forRemoval = true)
 	public ResponseEntity(MultiValueMap<String, String> headers, HttpStatusCode status) {
 		this(null, headers, status);
@@ -155,7 +158,7 @@ public ResponseEntity(MultiValueMap<String, String> headers, HttpStatusCode stat
 	 * @deprecated in favor of {@link #ResponseEntity(Object, HttpHeaders, int)}
 	 */
 	@Deprecated(since = "7.0", forRemoval = true)
-	public ResponseEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, int rawStatus) {
+	public ResponseEntity(T body, @Nullable MultiValueMap<String, String> headers, int rawStatus) {
 		this(body, headers, HttpStatusCode.valueOf(rawStatus));
 	}
 
@@ -168,7 +171,7 @@ public ResponseEntity(@Nullable T body, @Nullable MultiValueMap<String, String>
 	 */
 	@SuppressWarnings("removal")
 	@Deprecated(since = "7.0", forRemoval = true)
-	public ResponseEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, HttpStatusCode statusCode) {
+	public ResponseEntity(T body, @Nullable MultiValueMap<String, String> headers, HttpStatusCode statusCode) {
 		super(body, headers);
 		Assert.notNull(statusCode, "HttpStatusCode must not be null");
 
@@ -261,7 +264,7 @@ public static BodyBuilder ok() {
 	 * @return the created {@code ResponseEntity}
 	 * @since 4.1
 	 */
-	public static <T> ResponseEntity<T> ok(@Nullable T body) {
+	public static <T extends @Nullable Object> ResponseEntity<T> ok(T body) {
 		return ok().body(body);
 	}
 
@@ -294,7 +297,7 @@ public static HeadersBuilder<?> of(ProblemDetail body) {
 
 			@SuppressWarnings("unchecked")
 			@Override
-			public <T> ResponseEntity<T> build() {
+			public <T extends @Nullable Object> ResponseEntity<T> build() {
 				return (ResponseEntity<T>) body(body);
 			}
 		};
@@ -308,7 +311,7 @@ public <T> ResponseEntity<T> build() {
 	 * @return the created {@code ResponseEntity}
 	 * @since 6.0.5
 	 */
-	public static <T> ResponseEntity<T> ofNullable(@Nullable T body) {
+	public static <T extends @Nullable Object> ResponseEntity<T> ofNullable(T body) {
 		if (body == null) {
 			return notFound().build();
 		}
@@ -516,7 +519,7 @@ public interface HeadersBuilder<B extends HeadersBuilder<B>> {
 		 * @return the response entity
 		 * @see BodyBuilder#body(Object)
 		 */
-		<T> ResponseEntity<T> build();
+		<T extends @Nullable Object> ResponseEntity<T> build();
 	}
 
 
@@ -550,7 +553,7 @@ public interface BodyBuilder extends HeadersBuilder<BodyBuilder> {
 		 * @param body the body of the response entity
 		 * @return the built response entity
 		 */
-		<T> ResponseEntity<T> body(@Nullable T body);
+		<T extends @Nullable Object> ResponseEntity<T> body(T body);
 	}
 
 
@@ -652,13 +655,14 @@ public BodyBuilder varyBy(String... requestHeaders) {
 			return this;
 		}
 
+		@SuppressWarnings("NullAway")
 		@Override
-		public <T> ResponseEntity<T> build() {
+		public <T extends @Nullable Object> ResponseEntity<T> build() {
 			return body(null);
 		}
 
 		@Override
-		public <T> ResponseEntity<T> body(@Nullable T body) {
+		public <T extends @Nullable Object> ResponseEntity<T> body(T body) {
 			return new ResponseEntity<>(body, this.headers, this.statusCode);
 		}
 	}

spring-web/src/main/java/org/springframework/http/client/MultipartBodyBuilder.java

@@ -317,7 +317,7 @@ private HttpHeaders initHeadersIfNecessary() {
 		}
 
 		public HttpEntity<?> build() {
-			return new HttpEntity<>(this.body, this.headers);
+			return new HttpEntity<@Nullable Object>(this.body, this.headers);
 		}
 	}
 

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

@@ -1016,7 +1016,7 @@ private void logBody(Object body, @Nullable MediaType mediaType, HttpMessageConv
 	/**
 	 * Response extractor for {@link HttpEntity}.
 	 */
-	private class ResponseEntityResponseExtractor<T> implements ResponseExtractor<ResponseEntity<T>> {
+	private class ResponseEntityResponseExtractor<T> implements ResponseExtractor<ResponseEntity<@Nullable T>> {
 
 		private final @Nullable HttpMessageConverterExtractor<T> delegate;
 
@@ -1030,7 +1030,7 @@ public ResponseEntityResponseExtractor(@Nullable Type responseType) {
 		}
 
 		@Override
-		public ResponseEntity<T> extractData(ClientHttpResponse response) throws IOException {
+		public ResponseEntity<@Nullable T> extractData(ClientHttpResponse response) throws IOException {
 			if (this.delegate != null) {
 				T body = this.delegate.extractData(response);
 				return ResponseEntity.status(response.getStatusCode()).headers(response.getHeaders()).body(body);