Add request binding to functional endpoints

This commit introduces form binding to ServerRequest in both WebMVC.fn
and WebFlux.fn's, in the form of a bind(Class) method.

Closes gh-25943

spring-test/src/main/java/org/springframework/mock/web/reactive/function/server/MockServerRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -29,6 +29,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalLong;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
 
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -48,6 +49,7 @@ import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.reactive.function.server.HandlerStrategies;
 import org.springframework.web.reactive.function.server.ServerRequest;
@@ -219,6 +221,20 @@ public final class MockServerRequest implements ServerRequest {
 		return (Flux<S>) this.body;
 	}
 
+	@Override
+	@SuppressWarnings("unchecked")
+	public <T> Mono<T> bind(Class<T> bindType) {
+		Assert.state(this.body != null, "No body");
+		return (Mono<T>) this.body;
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public <T> Mono<T> bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) {
+		Assert.state(this.body != null, "No body");
+		return (Mono<T>) this.body;
+	}
+
 	@Override
 	public Map<String, Object> attributes() {
 		return this.attributes;

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

@@ -27,12 +27,14 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalLong;
+import java.util.function.Consumer;
 import java.util.function.Function;
 
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.codec.DecodingException;
 import org.springframework.core.codec.Hints;
 import org.springframework.core.io.buffer.DataBuffer;
@@ -49,7 +51,12 @@ import org.springframework.http.server.RequestPath;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
+import org.springframework.validation.BindingResult;
+import org.springframework.web.bind.WebDataBinder;
+import org.springframework.web.bind.support.WebExchangeDataBinder;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.reactive.function.BodyExtractors;
 import org.springframework.web.reactive.function.UnsupportedMediaTypeException;
@@ -220,6 +227,33 @@ class DefaultServerRequest implements ServerRequest {
 				.onErrorMap(DecodingException.class, DECODING_MAPPER);
 	}
 
+	@Override
+	@SuppressWarnings("unchecked")
+	public <T> Mono<T> bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) {
+		Assert.notNull(bindType, "BindType must not be null");
+		Assert.notNull(dataBinderCustomizer, "DataBinderCustomizer must not be null");
+
+		return Mono.defer(() -> {
+			WebExchangeDataBinder dataBinder = new WebExchangeDataBinder(null);
+			dataBinder.setTargetType(ResolvableType.forClass(bindType));
+			dataBinderCustomizer.accept(dataBinder);
+
+			ServerWebExchange exchange = exchange();
+			return dataBinder.construct(exchange)
+					.then(dataBinder.bind(exchange))
+					.then(Mono.defer(() -> {
+						BindingResult bindingResult = dataBinder.getBindingResult();
+						if (bindingResult.hasErrors()) {
+							return Mono.error(new BindException(bindingResult));
+						}
+						else {
+							T result = (T) bindingResult.getTarget();
+							return Mono.justOrEmpty(result);
+						}
+					}));
+		});
+	}
+
 	@Override
 	public Map<String, Object> attributes() {
 		return this.exchange.getAttributes();

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.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.
@@ -29,6 +29,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
@@ -52,6 +53,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.cors.reactive.CorsUtils;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.server.ServerWebExchange;
@@ -1044,6 +1046,16 @@ public abstract class RequestPredicates {
 			return this.request.bodyToFlux(typeReference);
 		}
 
+		@Override
+		public <T> Mono<T> bind(Class<T> bindType) {
+			return this.request.bind(bindType);
+		}
+
+		@Override
+		public <T> Mono<T> bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) {
+			return this.request.bind(bindType, dataBinderCustomizer);
+		}
+
 		@Override
 		public Map<String, Object> attributes() {
 			return this.attributes;

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/ServerRequest.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.
@@ -48,6 +48,8 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebSession;
@@ -197,6 +199,31 @@ public interface ServerRequest {
 	 */
 	<T> Flux<T> bodyToFlux(ParameterizedTypeReference<T> typeReference);
 
+	/**
+	 * Bind to this request and return an instance of the given type.
+	 * @param bindType the type of class to bind this request to
+	 * @param <T> the type to bind to
+	 * @return a mono containing either a constructed and bound instance of
+	 * {@code bindType}, or a {@link BindException} in case of binding errors
+	 * @since 6.1
+	 */
+	default <T> Mono<T> bind(Class<T> bindType) {
+		return bind(bindType, dataBinder -> {});
+	}
+
+	/**
+	 * Bind to this request and return an instance of the given type.
+	 * @param bindType the type of class to bind this request to
+	 * @param dataBinderCustomizer used to customize the data binder, e.g. set
+	 * (dis)allowed fields
+	 * @param <T> the type to bind to
+	 * @return a mono containing either a constructed and bound instance of
+	 * {@code bindType}, or a {@link BindException} in case of binding errors
+	 * @since 6.1
+	 */
+	<T> Mono<T> bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer);
+
+
 	/**
 	 * Get the request attribute value if present.
 	 * @param name the attribute name

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 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.
@@ -25,6 +25,7 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalLong;
+import java.util.function.Consumer;
 
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -42,6 +43,7 @@ import org.springframework.http.server.RequestPath;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.server.ServerWebExchange;
@@ -171,6 +173,16 @@ public class ServerRequestWrapper implements ServerRequest {
 		return this.delegate.bodyToFlux(typeReference);
 	}
 
+	@Override
+	public <T> Mono<T> bind(Class<T> bindType) {
+		return this.delegate.bind(bindType);
+	}
+
+	@Override
+	public <T> Mono<T> bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) {
+		return this.delegate.bind(bindType, dataBinderCustomizer);
+	}
+
 	@Override
 	public Optional<Object> attribute(String name) {
 		return this.delegate.attribute(name);

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

@@ -0,0 +1,236 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.reactive.function.server;
+
+import java.time.Duration;
+import java.util.Objects;
+
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+
+import org.springframework.lang.Nullable;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.WebClientResponseException;
+import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer;
+
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+
+/**
+ * @author Arjen Poutsma
+ */
+class BindingFunctionIntegrationTests extends AbstractRouterFunctionIntegrationTests {
+
+	private WebClient webClient;
+
+
+	@Override
+	protected void startServer(HttpServer httpServer) throws Exception {
+		super.startServer(httpServer);
+		this.webClient = WebClient.create("http://localhost:" + this.port);
+	}
+
+	@Override
+	protected RouterFunction<?> routerFunction() {
+		return route()
+				.GET("/constructor", request -> ServerResponse.ok().body(
+						request.bind(ConstructorInjection.class).map(Objects::toString), String.class))
+				.GET("/property", request -> ServerResponse.ok().body(
+						request.bind(PropertyInjection.class).map(Objects::toString), String.class))
+				.GET("/mixed", request -> ServerResponse.ok().body(
+						request.bind(MixedInjection.class).map(Objects::toString), String.class))
+				.GET("/customize", request -> ServerResponse.ok().body(
+						request.bind(PropertyInjection.class, dataBinder -> dataBinder.setAllowedFields("foo")).map(Objects::toString), String.class))
+				.GET("/error", request -> ServerResponse.ok().body(
+						request.bind(ErrorInjection.class).map(Objects::toString), String.class))
+				.build();
+	}
+
+	@ParameterizedHttpServerTest
+	void bindToConstructor(HttpServer httpServer) throws Exception {
+
+		startServer(httpServer);
+
+		Mono<String> result = this.webClient.get()
+				.uri("/constructor?foo=FOO&bar=BAR")
+				.retrieve()
+				.bodyToMono(String.class);
+
+		StepVerifier.create(result)
+				.expectNext("FOO:BAR")
+				.verifyComplete();
+	}
+
+	@ParameterizedHttpServerTest
+	void bindToProperties(HttpServer httpServer) throws Exception {
+
+		startServer(httpServer);
+
+		Mono<String> result = this.webClient.get()
+				.uri("/property?foo=FOO&bar=BAR")
+				.retrieve()
+				.bodyToMono(String.class);
+
+		StepVerifier.create(result)
+				.expectNext("FOO:BAR")
+				.verifyComplete();
+	}
+
+	@ParameterizedHttpServerTest
+	void bindToMixed(HttpServer httpServer) throws Exception {
+
+			startServer(httpServer);
+
+			Mono<String> result = this.webClient.get()
+					.uri("/mixed?foo=FOO&bar=BAR")
+					.retrieve()
+					.bodyToMono(String.class);
+
+		StepVerifier.create(result)
+				.expectNext("FOO:BAR")
+				.verifyComplete();
+	}
+
+	@ParameterizedHttpServerTest
+	void bindCustomizer(HttpServer httpServer) throws Exception {
+
+		startServer(httpServer);
+
+		Mono<String> result = this.webClient.get()
+				.uri("/customize?foo=FOO&bar=BAR")
+				.retrieve()
+				.bodyToMono(String.class);
+
+		StepVerifier.create(result)
+				.expectNext("FOO:null")
+				.verifyComplete();
+	}
+
+	@ParameterizedHttpServerTest
+	void bindError(HttpServer httpServer) throws Exception {
+
+		startServer(httpServer);
+
+		Mono<String> result = this.webClient.get()
+				.uri("/error?foo=FOO")
+				.retrieve()
+				.bodyToMono(String.class);
+
+		StepVerifier.create(result)
+				.expectError(WebClientResponseException.InternalServerError.class)
+				.verify(Duration.ofSeconds(5L));
+	}
+
+
+	private static final class ConstructorInjection {
+		private final String foo;
+
+		private final String bar;
+
+		public ConstructorInjection(String foo, String bar) {
+			this.foo = foo;
+			this.bar = bar;
+		}
+
+		public String getFoo() {
+			return this.foo;
+		}
+
+		public String getBar() {
+			return this.bar;
+		}
+
+		@Override
+		public String toString() {
+			return this.foo + ":" + this.bar;
+		}
+	}
+
+	private static final class PropertyInjection {
+		@Nullable
+		private String foo;
+
+		@Nullable
+		private String bar;
+
+		@Nullable
+		public String getFoo() {
+			return this.foo;
+		}
+
+		public void setFoo(String foo) {
+			this.foo = foo;
+		}
+
+		@Nullable
+		public String getBar() {
+			return this.bar;
+		}
+
+		public void setBar(String bar) {
+			this.bar = bar;
+		}
+
+		@Override
+		public String toString() {
+			return String.valueOf(this.foo) + ":" + String.valueOf(this.bar);
+		}
+	}
+
+	private static final class MixedInjection {
+		private final String foo;
+
+		@Nullable
+		private String bar;
+
+		public MixedInjection(String foo) {
+			this.foo = foo;
+		}
+
+		public String getFoo() {
+			return this.foo;
+		}
+
+		@Nullable
+		public String getBar() {
+			return this.bar;
+		}
+
+		public void setBar(String bar) {
+			this.bar = bar;
+		}
+
+		public String toString() {
+			return this.foo + ":" + String.valueOf(this.bar);
+		}
+
+	}
+
+	private static final class ErrorInjection {
+
+		private int foo;
+
+		public int getFoo() {
+			return this.foo;
+		}
+
+		public void setFoo(int foo) {
+			this.foo = foo;
+		}
+	}
+
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequest.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.
@@ -36,6 +36,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalLong;
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 import jakarta.servlet.ServletException;
@@ -47,6 +48,7 @@ import jakarta.servlet.http.HttpSession;
 import jakarta.servlet.http.Part;
 
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.ResolvableType;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpRange;
@@ -56,12 +58,17 @@ import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.server.RequestPath;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.ObjectUtils;
+import org.springframework.validation.BindException;
+import org.springframework.validation.BindingResult;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
+import org.springframework.web.bind.ServletRequestDataBinder;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.context.request.WebRequest;
 import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
@@ -218,6 +225,35 @@ class DefaultServerRequest implements ServerRequest {
 		return result;
 	}
 
+	@Override
+	@SuppressWarnings("unchecked")
+	public <T> T bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) throws BindException {
+		Assert.notNull(bindType, "BindType must not be null");
+		Assert.notNull(dataBinderCustomizer, "DataBinderCustomizer must not be null");
+
+		ServletRequestDataBinder dataBinder = new ServletRequestDataBinder(null);
+		dataBinder.setTargetType(ResolvableType.forClass(bindType));
+		dataBinderCustomizer.accept(dataBinder);
+
+		HttpServletRequest servletRequest = servletRequest();
+		dataBinder.construct(servletRequest);
+		dataBinder.bind(servletRequest);
+
+		BindingResult bindingResult = dataBinder.getBindingResult();
+		if (bindingResult.hasErrors()) {
+			throw new BindException(bindingResult);
+		}
+		else {
+			T result = (T) bindingResult.getTarget();
+			if (result != null) {
+				return result;
+			}
+			else {
+				throw new IllegalStateException("Binding result has neither target nor errors");
+			}
+		}
+	}
+
 	@Override
 	public Optional<Object> attribute(String name) {
 		return Optional.ofNullable(servletRequest().getAttribute(name));

spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequestBuilder.java

@@ -42,6 +42,7 @@ import jakarta.servlet.http.HttpSession;
 import jakarta.servlet.http.Part;
 
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.ResolvableType;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpMethod;
@@ -52,7 +53,11 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
+import org.springframework.validation.BindingResult;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
+import org.springframework.web.bind.ServletRequestDataBinder;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.util.UriBuilder;
 import org.springframework.web.util.UriComponentsBuilder;
 
@@ -323,6 +328,35 @@ class DefaultServerRequestBuilder implements ServerRequest.Builder {
 			throw new HttpMediaTypeNotSupportedException(contentType, Collections.emptyList(), method());
 		}
 
+		@Override
+		@SuppressWarnings("unchecked")
+		public <T> T bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) throws BindException {
+			Assert.notNull(bindType, "BindType must not be null");
+			Assert.notNull(dataBinderCustomizer, "DataBinderCustomizer must not be null");
+
+			ServletRequestDataBinder dataBinder = new ServletRequestDataBinder(null);
+			dataBinder.setTargetType(ResolvableType.forClass(bindType));
+			dataBinderCustomizer.accept(dataBinder);
+
+			HttpServletRequest servletRequest = servletRequest();
+			dataBinder.construct(servletRequest);
+			dataBinder.bind(servletRequest);
+
+			BindingResult bindingResult = dataBinder.getBindingResult();
+			if (bindingResult.hasErrors()) {
+				throw new BindException(bindingResult);
+			}
+			else {
+				T result = (T) bindingResult.getTarget();
+				if (result != null) {
+					return result;
+				}
+				else {
+					throw new IllegalStateException("Binding result has neither target nor errors");
+				}
+			}
+		}
+
 		@Override
 		public Map<String, Object> attributes() {
 			return this.attributes;

spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicates.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.
@@ -31,6 +31,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
@@ -54,6 +55,8 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.cors.CorsUtils;
 import org.springframework.web.util.UriBuilder;
 import org.springframework.web.util.UriUtils;
@@ -1018,6 +1021,16 @@ public abstract class RequestPredicates {
 			return this.request.body(bodyType);
 		}
 
+		@Override
+		public <T> T bind(Class<T> bindType) throws BindException {
+			return this.request.bind(bindType);
+		}
+
+		@Override
+		public <T> T bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) throws BindException {
+			return this.request.bind(bindType, dataBinderCustomizer);
+		}
+
 		@Override
 		public Optional<Object> attribute(String name) {
 			return this.request.attribute(name);

spring-webmvc/src/main/java/org/springframework/web/servlet/function/ServerRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 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.
@@ -48,6 +48,8 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
+import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.util.ServletRequestPathUtils;
 import org.springframework.web.util.UriBuilder;
 
@@ -148,6 +150,30 @@ public interface ServerRequest {
 	 */
 	<T> T body(ParameterizedTypeReference<T> bodyType) throws ServletException, IOException;
 
+	/**
+	 * Bind to this request and return an instance of the given type.
+	 * @param bindType the type of class to bind this request to
+	 * @param <T> the type to bind to
+	 * @return a constructed and bound instance of {@code bindType}
+	 * @throws BindException in case of binding errors
+	 * @since 6.1
+	 */
+	default <T> T bind(Class<T> bindType) throws BindException {
+		return bind(bindType, dataBinder -> {});
+	}
+
+	/**
+	 * Bind to this request and return an instance of the given type.
+	 * @param bindType the type of class to bind this request to
+	 * @param dataBinderCustomizer used to customize the data binder, e.g. set
+	 * (dis)allowed fields
+	 * @param <T> the type to bind to
+	 * @return a constructed and bound instance of {@code bindType}
+	 * @throws BindException in case of binding errors
+	 * @since 6.1
+	 */
+	<T> T bind(Class<T> bindType, Consumer<WebDataBinder> dataBinderCustomizer) throws BindException;
+
 	/**
 	 * Get the request attribute value if present.
 	 * @param name the attribute name

spring-webmvc/src/test/java/org/springframework/web/servlet/function/DefaultServerRequestTests.java

@@ -49,6 +49,7 @@ import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.BindException;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
 import org.springframework.web.servlet.handler.PathPatternsTestUtils;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
@@ -304,6 +305,71 @@ class DefaultServerRequestTests {
 		assertThat(request.principal()).contains(principal);
 	}
 
+	@Test
+	void bindToConstructor() throws BindException {
+		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest("GET", "/", true);
+		servletRequest.addParameter("foo", "FOO");
+		servletRequest.addParameter("bar", "BAR");
+
+		DefaultServerRequest request = new DefaultServerRequest(servletRequest, this.messageConverters);
+
+		ConstructorInjection result = request.bind(ConstructorInjection.class);
+		assertThat(result.getFoo()).isEqualTo("FOO");
+		assertThat(result.getBar()).isEqualTo("BAR");
+	}
+
+	@Test
+	void bindToProperties() throws BindException {
+		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest("GET", "/", true);
+		servletRequest.addParameter("foo", "FOO");
+		servletRequest.addParameter("bar", "BAR");
+
+		DefaultServerRequest request = new DefaultServerRequest(servletRequest, this.messageConverters);
+
+		PropertyInjection result = request.bind(PropertyInjection.class);
+		assertThat(result.getFoo()).isEqualTo("FOO");
+		assertThat(result.getBar()).isEqualTo("BAR");
+	}
+
+	@Test
+	void bindToMixed() throws BindException {
+		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest("GET", "/", true);
+		servletRequest.addParameter("foo", "FOO");
+		servletRequest.addParameter("bar", "BAR");
+
+		DefaultServerRequest request = new DefaultServerRequest(servletRequest, this.messageConverters);
+
+		MixedInjection result = request.bind(MixedInjection.class);
+		assertThat(result.getFoo()).isEqualTo("FOO");
+		assertThat(result.getBar()).isEqualTo("BAR");
+	}
+
+	@Test
+	void bindCustomizer() throws BindException {
+		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest("GET", "/", true);
+		servletRequest.addParameter("foo", "FOO");
+		servletRequest.addParameter("bar", "BAR");
+
+		DefaultServerRequest request = new DefaultServerRequest(servletRequest, this.messageConverters);
+
+		PropertyInjection result = request.bind(PropertyInjection.class, dataBinder -> dataBinder.setAllowedFields("foo"));
+		assertThat(result.getFoo()).isEqualTo("FOO");
+		assertThat(result.getBar()).isNull();
+	}
+
+	@Test
+	void bindError() throws BindException {
+		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest("GET", "/", true);
+		servletRequest.addParameter("foo", "FOO");
+
+		DefaultServerRequest request = new DefaultServerRequest(servletRequest, this.messageConverters);
+
+		assertThatExceptionOfType(BindException.class).isThrownBy(() ->
+			request.bind(ErrorInjection.class)
+		);
+	}
+
+
 	@ParameterizedHttpMethodTest
 	void checkNotModifiedTimestamp(String method) throws Exception {
 		MockHttpServletRequest servletRequest = PathPatternsTestUtils.initRequest(method, "/", true);
@@ -487,4 +553,83 @@ class DefaultServerRequestTests {
 	@interface ParameterizedHttpMethodTest {
 	}
 
+	private static final class ConstructorInjection {
+		private final String foo;
+
+		private final String bar;
+
+		public ConstructorInjection(String foo, String bar) {
+			this.foo = foo;
+			this.bar = bar;
+		}
+
+		public String getFoo() {
+			return this.foo;
+		}
+
+		public String getBar() {
+			return this.bar;
+		}
+	}
+
+	private static final class PropertyInjection {
+		private String foo;
+
+		private String bar;
+
+		public String getFoo() {
+			return this.foo;
+		}
+
+		public void setFoo(String foo) {
+			this.foo = foo;
+		}
+
+		public String getBar() {
+			return this.bar;
+		}
+
+		public void setBar(String bar) {
+			this.bar = bar;
+		}
+	}
+
+	private static final class MixedInjection {
+		private final String foo;
+
+		private String bar;
+
+		public MixedInjection(String foo) {
+			this.foo = foo;
+		}
+
+		public String getFoo() {
+			return this.foo;
+		}
+
+		public String getBar() {
+			return this.bar;
+		}
+
+		public void setBar(String bar) {
+			this.bar = bar;
+		}
+	}
+
+	private static final class ErrorInjection {
+
+		private int foo;
+
+		public int getFoo() {
+			return this.foo;
+		}
+
+		public void setFoo(int foo) {
+			this.foo = foo;
+		}
+	}
+
+
+
+
 }