Cache ServerHttpRequest::getMethod in AbstractServerHttpRequest

This commit ensures that the HttpMethod, exposed through
ServerHttpRequest::getMethod, is cached in AbstractServerHttpRequest so
that potentially expensive HTTP method lookups are only done once.

Closes gh-30139

spring-test/src/main/java/org/springframework/mock/http/server/reactive/MockServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -54,8 +54,6 @@
  */
 public final class MockServerHttpRequest extends AbstractServerHttpRequest {
 
-	private final HttpMethod httpMethod;
-
 	private final MultiValueMap<String, HttpCookie> cookies;
 
 	@Nullable
@@ -74,8 +72,7 @@ private MockServerHttpRequest(HttpMethod httpMethod,
 			@Nullable InetSocketAddress localAddress, @Nullable InetSocketAddress remoteAddress,
 			@Nullable SslInfo sslInfo, Publisher<? extends DataBuffer> body) {
 
-		super(uri, contextPath, headers);
-		this.httpMethod = httpMethod;
+		super(httpMethod, uri, contextPath, headers);
 		this.cookies = cookies;
 		this.localAddress = localAddress;
 		this.remoteAddress = remoteAddress;
@@ -84,11 +81,6 @@ private MockServerHttpRequest(HttpMethod httpMethod,
 	}
 
 
-	@Override
-	public HttpMethod getMethod() {
-		return this.httpMethod;
-	}
-
 	@Override
 	@Nullable
 	public InetSocketAddress getLocalAddress() {

spring-web/src/main/java/org/springframework/http/server/reactive/AbstractServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -24,8 +24,10 @@
 
 import org.springframework.http.HttpCookie;
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.server.RequestPath;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -49,6 +51,10 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 
 	private final HttpHeaders headers;
 
+	// TODO: remove @Nullable once deprecated constructors have been removed
+	@Nullable
+	private final HttpMethod method;
+
 	@Nullable
 	private MultiValueMap<String, String> queryParams;
 
@@ -71,23 +77,50 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 	 * @param contextPath the context path for the request
 	 * @param headers the headers for the request (as {@link MultiValueMap})
 	 * @since 5.3
+	 * @deprecated since 6.0.8, in favor of {@link #AbstractServerHttpRequest(HttpMethod, URI, String, MultiValueMap)}
 	 */
+	@Deprecated(since = "6.0.8", forRemoval = true)
 	public AbstractServerHttpRequest(URI uri, @Nullable String contextPath, MultiValueMap<String, String> headers) {
 		this.uri = uri;
 		this.path = RequestPath.parse(uri, contextPath);
 		this.headers = HttpHeaders.readOnlyHttpHeaders(headers);
+		this.method = null;
+	}
+
+	/**
+	 * Constructor with the method, URI and headers for the request.
+	 * @param method the HTTP method for the request
+	 * @param uri the URI for the request
+	 * @param contextPath the context path for the request
+	 * @param headers the headers for the request (as {@link MultiValueMap})
+	 * @since 6.0.8
+	 */
+	public AbstractServerHttpRequest(HttpMethod method, URI uri, @Nullable String contextPath,
+			MultiValueMap<String, String> headers) {
+
+		Assert.notNull(method, "Method must not be null");
+		Assert.notNull(uri, "Uri must not be null");
+		Assert.notNull(headers, "Headers must not be null");
+
+		this.method = method;
+		this.uri = uri;
+		this.path = RequestPath.parse(uri, contextPath);
+		this.headers = HttpHeaders.readOnlyHttpHeaders(headers);
 	}
 
 	/**
 	 * Constructor with the URI and headers for the request.
 	 * @param uri the URI for the request
 	 * @param contextPath the context path for the request
 	 * @param headers the headers for the request (as {@link HttpHeaders})
+	 * @deprecated since 6.0.8, in favor of {@link #AbstractServerHttpRequest(HttpMethod, URI, String, MultiValueMap)}
 	 */
+	@Deprecated(since = "6.0.8", forRemoval = true)
 	public AbstractServerHttpRequest(URI uri, @Nullable String contextPath, HttpHeaders headers) {
 		this.uri = uri;
 		this.path = RequestPath.parse(uri, contextPath);
 		this.headers = HttpHeaders.readOnlyHttpHeaders(headers);
+		this.method = null;
 	}
 
 
@@ -112,6 +145,18 @@ protected String initId() {
 		return null;
 	}
 
+	@Override
+	public HttpMethod getMethod() {
+		// TODO: remove null check once deprecated constructors have been removed
+		if (this.method != null) {
+			return this.method;
+		}
+		else {
+			throw new IllegalStateException("No HttpMethod provided in constructor, " +
+					"and AbstractServerHttpRequest::getMethod not overridden");
+		}
+	}
+
 	@Override
 	public URI getURI() {
 		return this.uri;

spring-web/src/main/java/org/springframework/http/server/reactive/DefaultServerHttpRequestBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -177,8 +177,6 @@ private URI getUriToUse() {
 
 	private static class MutatedServerHttpRequest extends AbstractServerHttpRequest {
 
-		private final HttpMethod method;
-
 		@Nullable
 		private final SslInfo sslInfo;
 
@@ -194,19 +192,13 @@ public MutatedServerHttpRequest(URI uri, @Nullable String contextPath,
 				HttpMethod method, @Nullable SslInfo sslInfo, @Nullable InetSocketAddress remoteAddress,
 				HttpHeaders headers, Flux<DataBuffer> body, ServerHttpRequest originalRequest) {
 
-			super(uri, contextPath, headers);
-			this.method = method;
+			super(method, uri, contextPath, headers);
 			this.remoteAddress = (remoteAddress != null ? remoteAddress : originalRequest.getRemoteAddress());
 			this.sslInfo = (sslInfo != null ? sslInfo : originalRequest.getSslInfo());
 			this.body = body;
 			this.originalRequest = originalRequest;
 		}
 
-		@Override
-		public HttpMethod getMethod() {
-			return this.method;
-		}
-
 		@Override
 		protected MultiValueMap<String, HttpCookie> initCookies() {
 			return this.originalRequest.getCookies();

spring-web/src/main/java/org/springframework/http/server/reactive/ReactorNetty2ServerHttpRequest.java

@@ -63,17 +63,15 @@ class ReactorNetty2ServerHttpRequest extends AbstractServerHttpRequest {
 
 	private final Netty5DataBufferFactory bufferFactory;
 
-	private final HttpMethod method;
-
 
 	public ReactorNetty2ServerHttpRequest(HttpServerRequest request, Netty5DataBufferFactory bufferFactory)
 			throws URISyntaxException {
 
-		super(initUri(request), "", new Netty5HeadersAdapter(request.requestHeaders()));
+		super(HttpMethod.valueOf(request.method().name()), initUri(request), "",
+				new Netty5HeadersAdapter(request.requestHeaders()));
 		Assert.notNull(bufferFactory, "DataBufferFactory must not be null");
 		this.request = request;
 		this.bufferFactory = bufferFactory;
-		this.method = HttpMethod.valueOf(request.method().name());
 	}
 
 	private static URI initUri(HttpServerRequest request) throws URISyntaxException {
@@ -142,11 +140,6 @@ private static String resolveRequestUri(HttpServerRequest request) {
 		return uri;
 	}
 
-	@Override
-	public HttpMethod getMethod() {
-		return this.method;
-	}
-
 	@Override
 	protected MultiValueMap<String, HttpCookie> initCookies() {
 		MultiValueMap<String, HttpCookie> cookies = new LinkedMultiValueMap<>();

spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java

@@ -61,17 +61,15 @@ class ReactorServerHttpRequest extends AbstractServerHttpRequest {
 
 	private final NettyDataBufferFactory bufferFactory;
 
-	private final HttpMethod method;
-
 
 	public ReactorServerHttpRequest(HttpServerRequest request, NettyDataBufferFactory bufferFactory)
 			throws URISyntaxException {
 
-		super(initUri(request), "", new NettyHeadersAdapter(request.requestHeaders()));
+		super(HttpMethod.valueOf(request.method().name()), initUri(request), "",
+				new NettyHeadersAdapter(request.requestHeaders()));
 		Assert.notNull(bufferFactory, "DataBufferFactory must not be null");
 		this.request = request;
 		this.bufferFactory = bufferFactory;
-		this.method = HttpMethod.valueOf(request.method().name());
 	}
 
 	private static URI initUri(HttpServerRequest request) throws URISyntaxException {
@@ -112,10 +110,6 @@ private static String resolveRequestUri(HttpServerRequest request) {
 		return uri;
 	}
 
-	@Override
-	public HttpMethod getMethod() {
-		return this.method;
-	}
 
 	@Override
 	protected MultiValueMap<String, HttpCookie> initCookies() {

spring-web/src/main/java/org/springframework/http/server/reactive/ServletServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -90,7 +90,8 @@ public ServletServerHttpRequest(MultiValueMap<String, String> headers, HttpServl
 			AsyncContext asyncContext, String servletPath, DataBufferFactory bufferFactory, int bufferSize)
 			throws IOException, URISyntaxException {
 
-		super(initUri(request), request.getContextPath() + servletPath, initHeaders(headers, request));
+		super(HttpMethod.valueOf(request.getMethod()), initUri(request), request.getContextPath() + servletPath,
+				initHeaders(headers, request));
 
 		Assert.notNull(bufferFactory, "'bufferFactory' must not be null");
 		Assert.isTrue(bufferSize > 0, "'bufferSize' must be greater than 0");
@@ -162,11 +163,6 @@ private static MultiValueMap<String, String> initHeaders(
 		return (headers != null ? headers : headerValues);
 	}
 
-	@Override
-	public HttpMethod getMethod() {
-		return HttpMethod.valueOf(this.request.getMethod());
-	}
-
 	@Override
 	protected MultiValueMap<String, HttpCookie> initCookies() {
 		MultiValueMap<String, HttpCookie> httpCookies = new LinkedMultiValueMap<>();

spring-web/src/main/java/org/springframework/http/server/reactive/UndertowServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -64,7 +64,8 @@ class UndertowServerHttpRequest extends AbstractServerHttpRequest {
 	public UndertowServerHttpRequest(HttpServerExchange exchange, DataBufferFactory bufferFactory)
 			throws URISyntaxException {
 
-		super(initUri(exchange), "", new UndertowHeadersAdapter(exchange.getRequestHeaders()));
+		super(HttpMethod.valueOf(exchange.getRequestMethod().toString()), initUri(exchange), "",
+				new UndertowHeadersAdapter(exchange.getRequestHeaders()));
 		this.exchange = exchange;
 		this.body = new RequestBodyPublisher(exchange, bufferFactory);
 		this.body.registerListeners(exchange);
@@ -78,11 +79,6 @@ private static URI initUri(HttpServerExchange exchange) throws URISyntaxExceptio
 		return new URI(requestUriAndQuery);
 	}
 
-	@Override
-	public HttpMethod getMethod() {
-		return HttpMethod.valueOf(this.exchange.getRequestMethod().toString());
-	}
-
 	@Override
 	protected MultiValueMap<String, HttpCookie> initCookies() {
 		MultiValueMap<String, HttpCookie> cookies = new LinkedMultiValueMap<>();

spring-web/src/testFixtures/java/org/springframework/web/testfixture/http/server/reactive/MockServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -55,8 +55,6 @@
  */
 public final class MockServerHttpRequest extends AbstractServerHttpRequest {
 
-	private final HttpMethod httpMethod;
-
 	private final MultiValueMap<String, HttpCookie> cookies;
 
 	@Nullable
@@ -75,8 +73,7 @@ private MockServerHttpRequest(HttpMethod httpMethod,
 			@Nullable InetSocketAddress localAddress, @Nullable InetSocketAddress remoteAddress,
 			@Nullable SslInfo sslInfo, Publisher<? extends DataBuffer> body) {
 
-		super(uri, contextPath, headers);
-		this.httpMethod = httpMethod;
+		super(httpMethod, uri, contextPath, headers);
 		this.cookies = cookies;
 		this.localAddress = localAddress;
 		this.remoteAddress = remoteAddress;
@@ -85,11 +82,6 @@ private MockServerHttpRequest(HttpMethod httpMethod,
 	}
 
 
-	@Override
-	public HttpMethod getMethod() {
-		return this.httpMethod;
-	}
-
 	@Override
 	@Nullable
 	public InetSocketAddress getLocalAddress() {