Use existing context path in DefaultServerRequestBuilder

Closes gh-28820

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/DefaultServerRequestBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -75,6 +75,9 @@ class DefaultServerRequestBuilder implements ServerRequest.Builder {
 
 	private URI uri;
 
+	@Nullable
+	private String contextPath;
+
 	private final HttpHeaders headers = new HttpHeaders();
 
 	private final MultiValueMap<String, HttpCookie> cookies = new LinkedMultiValueMap<>();
@@ -90,6 +93,7 @@ class DefaultServerRequestBuilder implements ServerRequest.Builder {
 		this.exchange = other.exchange();
 		this.method = other.method();
 		this.uri = other.uri();
+		this.contextPath = other.requestPath().contextPath().value();
 		this.headers.addAll(other.headers().asHttpHeaders());
 		this.cookies.addAll(other.cookies());
 		this.attributes.putAll(other.attributes());
@@ -110,6 +114,12 @@ public ServerRequest.Builder uri(URI uri) {
 		return this;
 	}
 
+	@Override
+	public ServerRequest.Builder contextPath(@Nullable String contextPath) {
+		this.contextPath = contextPath;
+		return this;
+	}
+
 	@Override
 	public ServerRequest.Builder header(String headerName, String... headerValues) {
 		for (String headerValue : headerValues) {
@@ -177,7 +187,7 @@ public ServerRequest.Builder attributes(Consumer<Map<String, Object>> attributes
 	@Override
 	public ServerRequest build() {
 		ServerHttpRequest serverHttpRequest = new BuiltServerHttpRequest(this.exchange.getRequest().getId(),
-				this.method, this.uri, this.headers, this.cookies, this.body);
+				this.method, this.uri, this.contextPath, this.headers, this.cookies, this.body);
 		ServerWebExchange exchange = new DelegatingServerWebExchange(
 				serverHttpRequest, this.attributes, this.exchange, this.messageReaders);
 		return new DefaultServerRequest(exchange, this.messageReaders);
@@ -204,13 +214,13 @@ private static class BuiltServerHttpRequest implements ServerHttpRequest {
 
 		private final Flux<DataBuffer> body;
 
-		public BuiltServerHttpRequest(String id, HttpMethod method, URI uri, HttpHeaders headers,
-				MultiValueMap<String, HttpCookie> cookies, Flux<DataBuffer> body) {
+		public BuiltServerHttpRequest(String id, HttpMethod method, URI uri, @Nullable String contextPath,
+				HttpHeaders headers, MultiValueMap<String, HttpCookie> cookies, Flux<DataBuffer> body) {
 
 			this.id = id;
 			this.method = method;
 			this.uri = uri;
-			this.path = RequestPath.parse(uri, null);
+			this.path = RequestPath.parse(uri, contextPath);
 			this.headers = HttpHeaders.readOnlyHttpHeaders(headers);
 			this.cookies = unmodifiableCopy(cookies);
 			this.queryParams = parseQueryParams(uri);

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/ServerRequest.java

@@ -528,6 +528,14 @@ interface Builder {
 		 */
 		Builder uri(URI uri);
 
+		/**
+		 * Set the context path of the request.
+		 * @param contextPath the new context path
+		 * @return this builder
+		 * @since 5.3.23
+		 */
+		Builder contextPath(@Nullable String contextPath);
+
 		/**
 		 * Add the given header value(s) under the given name.
 		 * @param headerName the header name

spring-webflux/src/test/java/org/springframework/web/reactive/function/server/DefaultServerRequestBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.web.reactive.function.server;
 
+import java.net.URI;
 import java.nio.charset.StandardCharsets;
 
 import org.junit.jupiter.api.Test;
@@ -56,8 +57,11 @@ public void from() {
 				.map(s -> s.getBytes(StandardCharsets.UTF_8))
 				.map(DefaultDataBufferFactory.sharedInstance::wrap);
 
+		URI uri = URI.create("https://example2.com/foo/bar");
 		ServerRequest result = ServerRequest.from(other)
 				.method(HttpMethod.HEAD)
+				.uri(uri)
+				.contextPath("/foo")
 				.headers(httpHeaders -> httpHeaders.set("foo", "baar"))
 				.cookies(cookies -> cookies.set("baz", ResponseCookie.from("baz", "quux").build()))
 				.attribute("attr2", "value2")
@@ -66,6 +70,9 @@ public void from() {
 				.build();
 
 		assertThat(result.method()).isEqualTo(HttpMethod.HEAD);
+		assertThat(result.uri()).isEqualTo(uri);
+		assertThat(result.requestPath().pathWithinApplication().value()).isEqualTo("/bar");
+		assertThat(result.requestPath().contextPath().value()).isEqualTo("/foo");
 		assertThat(result.headers().asHttpHeaders()).hasSize(1);
 		assertThat(result.headers().asHttpHeaders().getFirst("foo")).isEqualTo("baar");
 		assertThat(result.cookies()).hasSize(1);