Fix missing request body for GET and DELETE JdkClientHttpRequest

This commit fixes a regression introduced in gh-34971 where GET and
DELETE requests would not allow request bodies anymore for
`JdkClientHttpRequest`.
We are now using `builder.GET()` and `builder.DELETE()` methods only if
the provided body is null.

Fixes gh-35068

Author: bclozel

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

@@ -149,38 +149,38 @@ private HttpRequest buildRequest(HttpHeaders headers, @Nullable Body body) {
 			}
 		});
 
-		switch (this.method.name()) {
-			case "GET" :
-				builder.GET();
-				break;
-			case "DELETE" :
-				builder.DELETE();
-				break;
-			default :
-				builder.method(this.method.name(), bodyPublisher(headers, body));
+		if (body != null) {
+			builder.method(this.method.name(), bodyPublisher(headers, body));
+		}
+		else {
+			switch (this.method.name()) {
+				case "GET" :
+					builder.GET();
+					break;
+				case "DELETE" :
+					builder.DELETE();
+					break;
+				default :
+					builder.method(this.method.name(), HttpRequest.BodyPublishers.noBody());
+			}
 		}
 		return builder.build();
 	}
 
-	private HttpRequest.BodyPublisher bodyPublisher(HttpHeaders headers, @Nullable Body body) {
-		if (body != null) {
-			Flow.Publisher<ByteBuffer> publisher = new OutputStreamPublisher<>(
-					os -> body.writeTo(StreamUtils.nonClosing(os)), BYTE_MAPPER, this.executor, null);
+	private HttpRequest.BodyPublisher bodyPublisher(HttpHeaders headers, Body body) {
+		Flow.Publisher<ByteBuffer> publisher = new OutputStreamPublisher<>(
+				os -> body.writeTo(StreamUtils.nonClosing(os)), BYTE_MAPPER, this.executor, null);
 
-			long contentLength = headers.getContentLength();
-			if (contentLength > 0) {
-				return HttpRequest.BodyPublishers.fromPublisher(publisher, contentLength);
-			}
-			else if (contentLength == 0) {
-				return HttpRequest.BodyPublishers.noBody();
-			}
-			else {
-				return HttpRequest.BodyPublishers.fromPublisher(publisher);
-			}
+		long contentLength = headers.getContentLength();
+		if (contentLength > 0) {
+			return HttpRequest.BodyPublishers.fromPublisher(publisher, contentLength);
 		}
-		else {
+		else if (contentLength == 0) {
 			return HttpRequest.BodyPublishers.noBody();
 		}
+		else {
+			return HttpRequest.BodyPublishers.fromPublisher(publisher);
+		}
 	}
 
 	/**

spring-web/src/test/java/org/springframework/http/client/JdkClientHttpRequestFactoryTests.java

@@ -93,10 +93,21 @@ public void contentLength0() throws IOException {
 		}
 	}
 
+	@Test // gh-35068
+	void deleteRequestWithBody() throws Exception {
+		URI uri = URI.create(baseUrl + "/echo");
+		ClientHttpRequest request = this.factory.createRequest(uri, HttpMethod.DELETE);
+		StreamUtils.copy("body", StandardCharsets.ISO_8859_1, request.getBody());
+		try (ClientHttpResponse response = request.execute()) {
+			assertThat(response.getStatusCode()).as("Invalid response status").isEqualTo(HttpStatus.OK);
+			assertThat(StreamUtils.copyToString(response.getBody(), StandardCharsets.ISO_8859_1))
+					.as("Invalid request body").isEqualTo("body");
+		}
+	}
 
 	@Test // gh-34971
 	@EnabledForJreRange(min = JRE.JAVA_19) // behavior fixed in Java 19
-	void requestContentLengthHeader() throws Exception {
+	void requestContentLengthHeaderWhenNoBody() throws Exception {
 		URI uri = URI.create(baseUrl + "/header/Content-Length");
 		assertNoContentLength(uri, HttpMethod.GET);
 		assertNoContentLength(uri, HttpMethod.DELETE);