Fine-tuned assertions and related polishing in WebFlux builders

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

@@ -125,14 +125,10 @@ public final class MultipartBodyBuilder {
 	 * @param elementClass the type of elements contained in the publisher
 	 * @return builder that allows for further customization of part headers
 	 */
-	public <T, P extends Publisher<T>> PartBuilder asyncPart(String name, P publisher,
-			Class<T> elementClass) {
-
-		Assert.notNull(elementClass, "'elementClass' must not be null");
-		ResolvableType elementType = ResolvableType.forClass(elementClass);
+	public <T, P extends Publisher<T>> PartBuilder asyncPart(String name, P publisher, Class<T> elementClass) {
 		Assert.hasLength(name, "'name' must not be empty");
 		Assert.notNull(publisher, "'publisher' must not be null");
-		Assert.notNull(elementType, "'elementType' must not be null");
+		Assert.notNull(elementClass, "'elementClass' must not be null");
 
 		HttpHeaders headers = new HttpHeaders();
 		PublisherPartBuilder<T, P> builder = new PublisherPartBuilder<>(headers, publisher, elementClass);
@@ -150,14 +146,12 @@ public final class MultipartBodyBuilder {
 	 * @param typeReference the type of elements contained in the publisher
 	 * @return builder that allows for further customization of part headers
 	 */
-	public <T, P extends Publisher<T>> PartBuilder asyncPart(String name, P publisher,
-			ParameterizedTypeReference<T> typeReference) {
+	public <T, P extends Publisher<T>> PartBuilder asyncPart(
+			String name, P publisher, ParameterizedTypeReference<T> typeReference) {
 
-		Assert.notNull(typeReference, "'typeReference' must not be null");
-		ResolvableType elementType1 = ResolvableType.forType(typeReference);
 		Assert.hasLength(name, "'name' must not be empty");
 		Assert.notNull(publisher, "'publisher' must not be null");
-		Assert.notNull(elementType1, "'typeReference' must not be null");
+		Assert.notNull(typeReference, "'typeReference' must not be null");
 
 		HttpHeaders headers = new HttpHeaders();
 		PublisherPartBuilder<T, P> builder = new PublisherPartBuilder<>(headers, publisher, typeReference);
@@ -210,7 +204,6 @@ public final class MultipartBodyBuilder {
 		@Nullable
 		protected final Object body;
 
-
 		public DefaultPartBuilder(HttpHeaders headers, @Nullable Object body) {
 			this.headers = headers;
 			this.body = body;
@@ -224,7 +217,6 @@ public final class MultipartBodyBuilder {
 
 		@Override
 		public PartBuilder headers(Consumer<HttpHeaders> headersConsumer) {
-			Assert.notNull(headersConsumer, "'headersConsumer' must not be null");
 			headersConsumer.accept(this.headers);
 			return this;
 		}
@@ -239,7 +231,6 @@ public final class MultipartBodyBuilder {
 
 		private final ResolvableType resolvableType;
 
-
 		public PublisherPartBuilder(HttpHeaders headers, P body, Class<S> elementClass) {
 			super(headers, body);
 			this.resolvableType = ResolvableType.forClass(elementClass);
@@ -255,12 +246,11 @@ public final class MultipartBodyBuilder {
 			this.resolvableType = other.getResolvableType();
 		}
 
-
 		@Override
 		@SuppressWarnings("unchecked")
 		public HttpEntity<?> build() {
 			P publisher = (P) this.body;
-			Assert.state(publisher != null, "'publisher' must not be null");
+			Assert.state(publisher != null, "Publisher must not be null");
 			return new PublisherEntity<>(this.headers, publisher, this.resolvableType);
 		}
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.http.server.reactive;
 
 import java.util.function.BiFunction;
@@ -32,7 +33,6 @@ import org.springframework.core.io.buffer.DataBufferUtils;
  */
 public class HttpHeadResponseDecorator extends ServerHttpResponseDecorator {
 
-
 	public HttpHeadResponseDecorator(ServerHttpResponse delegate) {
 		super(delegate);
 	}
@@ -45,9 +45,7 @@ public class HttpHeadResponseDecorator extends ServerHttpResponseDecorator {
 	 */
 	@Override
 	public final Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
-
 		// After Reactor Netty #171 is fixed we can return without delegating
-
 		return getDelegate().writeWith(
 				Flux.from(body)
 						.reduce(0, (current, buffer) -> {
@@ -61,7 +59,6 @@ public class HttpHeadResponseDecorator extends ServerHttpResponseDecorator {
 
 	/**
 	 * Invoke {@link #setComplete()} without writing.
-	 *
 	 * <p>RFC 7302 allows HTTP HEAD response without content-length and it's not
 	 * something that can be computed on a streaming response.
 	 */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -43,7 +43,7 @@ public class ServerHttpRequestDecorator implements ServerHttpRequest {
 
 
 	public ServerHttpRequestDecorator(ServerHttpRequest delegate) {
-		Assert.notNull(delegate, "ServerHttpRequest delegate is required.");
+		Assert.notNull(delegate, "Delegate is required");
 		this.delegate = delegate;
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -42,7 +42,7 @@ public class ServerHttpResponseDecorator implements ServerHttpResponse {
 
 
 	public ServerHttpResponseDecorator(ServerHttpResponse delegate) {
-		Assert.notNull(delegate, "ServerHttpResponse delegate is required.");
+		Assert.notNull(delegate, "Delegate is required");
 		this.delegate = delegate;
 	}
 

spring-web/src/main/java/org/springframework/web/util/pattern/PathPattern.java

@@ -310,7 +310,8 @@ public class PathPattern implements Comparable<PathPattern> {
 				}
 			}
 			resultPath = PathContainer.parsePath(buf.toString());
-		} else if (startIndex >= endIndex) {
+		}
+		else if (startIndex >= endIndex) {
 			resultPath = PathContainer.parsePath("");
 		}
 		else {

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

@@ -212,7 +212,7 @@ public abstract class BodyInserters {
 	 * @return the inserter that allows adding more form data
 	 */
 	public static FormInserter<String> fromFormData(String name, String value) {
-		Assert.notNull(name, "'key' must not be null");
+		Assert.notNull(name, "'name' must not be null");
 		Assert.notNull(value, "'value' must not be null");
 		return new DefaultFormInserter().with(name, value);
 	}
@@ -221,11 +221,9 @@ public abstract class BodyInserters {
 	 * Return a {@link MultipartInserter} that writes the given
 	 * {@code MultiValueMap} as multipart data. Values in the map can be an
 	 * Object or an {@link HttpEntity}.
-	 *
 	 * <p>Note that you can also build the multipart data externally with
 	 * {@link MultipartBodyBuilder}, and pass the resulting map directly to the
 	 * {@code syncBody(Object)} shortcut method in {@code WebClient}.
-	 *
 	 * @param multipartData the form data to write to the output message
 	 * @return the inserter that allows adding more parts
 	 * @see MultipartBodyBuilder
@@ -239,17 +237,15 @@ public abstract class BodyInserters {
 	 * Return a {@link MultipartInserter} that writes the given parts,
 	 * as multipart data. Values in the map can be an Object or an
 	 * {@link HttpEntity}.
-	 *
 	 * <p>Note that you can also build the multipart data externally with
 	 * {@link MultipartBodyBuilder}, and pass the resulting map directly to the
 	 * {@code syncBody(Object)} shortcut method in {@code WebClient}.
-	 *
 	 * @param name the part name
 	 * @param value the part value, an Object or {@code HttpEntity}
 	 * @return the inserter that allows adding more parts
 	 */
 	public static MultipartInserter fromMultipartData(String name, Object value) {
-		Assert.notNull(name, "'key' must not be null");
+		Assert.notNull(name, "'name' must not be null");
 		Assert.notNull(value, "'value' must not be null");
 		return new DefaultMultipartInserter().with(name, value);
 	}
@@ -257,22 +253,16 @@ public abstract class BodyInserters {
 	/**
 	 * Return a {@link MultipartInserter} that writes the given asynchronous parts,
 	 * as multipart data.
-	 *
 	 * <p>Note that you can also build the multipart data externally with
 	 * {@link MultipartBodyBuilder}, and pass the resulting map directly to the
 	 * {@code syncBody(Object)} shortcut method in {@code WebClient}.
-	 *
 	 * @param name the part name
 	 * @param publisher the publisher that forms the part value
 	 * @param elementClass the class contained in the {@code publisher}
 	 * @return the inserter that allows adding more parts
 	 */
-	public static <T, P extends Publisher<T>> MultipartInserter fromMultipartAsyncData(String name,
-			P publisher, Class<T> elementClass) {
-
-		Assert.notNull(name, "'key' must not be null");
-		Assert.notNull(publisher, "'publisher' must not be null");
-		Assert.notNull(elementClass, "'elementClass' must not be null");
+	public static <T, P extends Publisher<T>> MultipartInserter fromMultipartAsyncData(
+			String name, P publisher, Class<T> elementClass) {
 
 		return new DefaultMultipartInserter().withPublisher(name, publisher, elementClass);
 	}
@@ -281,22 +271,16 @@ public abstract class BodyInserters {
 	 * Variant of {@link #fromMultipartAsyncData(String, Publisher, Class)} that
 	 * accepts a {@link ParameterizedTypeReference} for the element type, which
 	 * allows specifying generic type information.
-	 *
 	 * <p>Note that you can also build the multipart data externally with
 	 * {@link MultipartBodyBuilder}, and pass the resulting map directly to the
 	 * {@code syncBody(Object)} shortcut method in {@code WebClient}.
-	 *
 	 * @param name the part name
 	 * @param publisher the publisher that forms the part value
 	 * @param typeReference the type contained in the {@code publisher}
 	 * @return the inserter that allows adding more parts
 	 */
-	public static <T, P extends Publisher<T>> MultipartInserter fromMultipartAsyncData(String name,
-			P publisher, ParameterizedTypeReference<T> typeReference) {
-
-		Assert.notNull(name, "'key' must not be null");
-		Assert.notNull(publisher, "'publisher' must not be null");
-		Assert.notNull(typeReference, "'typeReference' must not be null");
+	public static <T, P extends Publisher<T>> MultipartInserter fromMultipartAsyncData(
+			String name, P publisher, ParameterizedTypeReference<T> typeReference) {
 
 		return new DefaultMultipartInserter().withPublisher(name, publisher, typeReference);
 	}
@@ -312,7 +296,7 @@ public abstract class BodyInserters {
 	public static <T extends Publisher<DataBuffer>> BodyInserter<T, ReactiveHttpOutputMessage> fromDataBuffers(
 			T publisher) {
 
-		Assert.notNull(publisher, "'publisher' must not be null");
+		Assert.notNull(publisher, "Publisher must not be null");
 		return (outputMessage, context) -> outputMessage.writeWith(publisher);
 	}
 
@@ -333,9 +317,9 @@ public abstract class BodyInserters {
 							return messageWriter.write(body, bodyType, bodyType, contentType,
 									serverRequest.get(), (ServerHttpResponse) outputMessage,
 									context.hints());
-						} else {
-							return messageWriter.write(body, bodyType, contentType, outputMessage,
-											context.hints());
+						}
+						else {
+							return messageWriter.write(body, bodyType, contentType, outputMessage, context.hints());
 						}
 					})
 					.orElseGet(() -> {
@@ -500,4 +484,5 @@ public abstract class BodyInserters {
 					outputMessage, context.hints());
 		}
 	}
+
 }

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ClientRequest.java

@@ -28,7 +28,6 @@ import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.client.reactive.ClientHttpRequest;
-import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyInserter;
 
@@ -109,7 +108,6 @@ public interface ClientRequest {
 	 * @return the created builder
 	 */
 	static Builder from(ClientRequest other) {
-		Assert.notNull(other, "'other' must not be null");
 		return new DefaultClientRequestBuilder(other);
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ClientResponse.java

@@ -35,7 +35,6 @@ import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.reactive.ClientHttpResponse;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
-import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyExtractor;
 
@@ -160,7 +159,6 @@ public interface ClientResponse {
 	 * @return the created builder
 	 */
 	static Builder from(ClientResponse other) {
-		Assert.notNull(other, "Other ClientResponse must not be null");
 		return new DefaultClientResponseBuilder(other);
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultClientRequestBuilder.java

@@ -47,7 +47,7 @@ import org.springframework.web.reactive.function.BodyInserters;
  * @author Arjen Poutsma
  * @since 5.0
  */
-class DefaultClientRequestBuilder implements ClientRequest.Builder {
+final class DefaultClientRequestBuilder implements ClientRequest.Builder {
 
 	private final HttpHeaders headers = new HttpHeaders();
 
@@ -63,18 +63,21 @@ class DefaultClientRequestBuilder implements ClientRequest.Builder {
 
 
 	public DefaultClientRequestBuilder(HttpMethod method, URI url) {
-		this.method = method;
-		this.url = url;
+		method(method);
+		url(url);
 	}
 
 	public DefaultClientRequestBuilder(ClientRequest other) {
-		this(other.method(), other.url());
+		Assert.notNull(other, "ClientRequest must not be null");
+		method(other.method());
+		url(other.url());
 		headers(headers -> headers.addAll(other.headers()));
 		cookies(cookies -> cookies.addAll(other.cookies()));
 		attributes(attributes -> attributes.putAll(other.attributes()));
 		body(other.body());
 	}
 
+
 	@Override
 	public ClientRequest.Builder method(HttpMethod method) {
 		Assert.notNull(method, "'method' must not be null");
@@ -99,7 +102,6 @@ class DefaultClientRequestBuilder implements ClientRequest.Builder {
 
 	@Override
 	public ClientRequest.Builder headers(Consumer<HttpHeaders> headersConsumer) {
-		Assert.notNull(headersConsumer, "'headersConsumer' must not be null");
 		headersConsumer.accept(this.headers);
 		return this;
 	}
@@ -114,7 +116,6 @@ class DefaultClientRequestBuilder implements ClientRequest.Builder {
 
 	@Override
 	public ClientRequest.Builder cookies(Consumer<MultiValueMap<String, String>> cookiesConsumer) {
-		Assert.notNull(cookiesConsumer, "'cookiesConsumer' must not be null");
 		cookiesConsumer.accept(this.cookies);
 		return this;
 	}
@@ -129,8 +130,8 @@ class DefaultClientRequestBuilder implements ClientRequest.Builder {
 	}
 
 	@Override
-	public <S, P extends Publisher<S>> ClientRequest.Builder body(P publisher,
-			ParameterizedTypeReference<S> typeReference) {
+	public <S, P extends Publisher<S>> ClientRequest.Builder body(
+			P publisher, ParameterizedTypeReference<S> typeReference) {
 
 		Assert.notNull(publisher, "'publisher' must not be null");
 		Assert.notNull(typeReference, "'typeReference' must not be null");
@@ -147,7 +148,6 @@ class DefaultClientRequestBuilder implements ClientRequest.Builder {
 
 	@Override
 	public ClientRequest.Builder attributes(Consumer<Map<String, Object>> attributesConsumer) {
-		Assert.notNull(attributesConsumer, "'attributesConsumer' must not be null");
 		attributesConsumer.accept(this.attributes);
 		return this;
 	}

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultClientResponseBuilder.java

@@ -40,7 +40,7 @@ import org.springframework.util.MultiValueMap;
  * @author Arjen Poutsma
  * @since 5.0.5
  */
-class DefaultClientResponseBuilder implements ClientResponse.Builder {
+final class DefaultClientResponseBuilder implements ClientResponse.Builder {
 
 	private final HttpHeaders headers = new HttpHeaders();
 
@@ -59,7 +59,8 @@ class DefaultClientResponseBuilder implements ClientResponse.Builder {
 	}
 
 	public DefaultClientResponseBuilder(ClientResponse other) {
-		this(other.strategies());
+		Assert.notNull(other, "ClientResponse must not be null");
+		this.strategies = other.strategies();
 		statusCode(other.statusCode());
 		headers(headers -> headers.addAll(other.headers().asHttpHeaders()));
 		cookies(cookies -> cookies.addAll(other.cookies()));

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultExchangeStrategiesBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -24,7 +24,6 @@ import java.util.function.Consumer;
 import org.springframework.http.codec.ClientCodecConfigurer;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
-import org.springframework.util.Assert;
 
 /**
  * Default implementation of {@link ExchangeStrategies.Builder}.
@@ -32,7 +31,7 @@ import org.springframework.util.Assert;
  * @author Arjen Poutsma
  * @since 5.0
  */
-class DefaultExchangeStrategiesBuilder implements ExchangeStrategies.Builder {
+final class DefaultExchangeStrategiesBuilder implements ExchangeStrategies.Builder {
 
 	private final ClientCodecConfigurer codecConfigurer = ClientCodecConfigurer.create();
 
@@ -41,13 +40,13 @@ class DefaultExchangeStrategiesBuilder implements ExchangeStrategies.Builder {
 		this.codecConfigurer.registerDefaults(false);
 	}
 
+
 	public void defaultConfiguration() {
 		this.codecConfigurer.registerDefaults(true);
 	}
 
 	@Override
 	public ExchangeStrategies.Builder codecs(Consumer<ClientCodecConfigurer> consumer) {
-		Assert.notNull(consumer, "'consumer' must not be null");
 		consumer.accept(this.codecConfigurer);
 		return this;
 	}

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultWebClient.java

@@ -215,7 +215,6 @@ class DefaultWebClient implements WebClient {
 
 		@Override
 		public DefaultRequestBodyUriSpec headers(Consumer<HttpHeaders> headersConsumer) {
-			Assert.notNull(headersConsumer, "'headersConsumer' must not be null");
 			headersConsumer.accept(getHeaders());
 			return this;
 		}
@@ -228,7 +227,6 @@ class DefaultWebClient implements WebClient {
 
 		@Override
 		public RequestBodySpec attributes(Consumer<Map<String, Object>> attributesConsumer) {
-			Assert.notNull(attributesConsumer, "'attributesConsumer' must not be null");
 			attributesConsumer.accept(this.attributes);
 			return this;
 		}
@@ -265,7 +263,6 @@ class DefaultWebClient implements WebClient {
 
 		@Override
 		public DefaultRequestBodyUriSpec cookies(Consumer<MultiValueMap<String, String>> cookiesConsumer) {
-			Assert.notNull(cookiesConsumer, "'cookiesConsumer' must not be null");
 			cookiesConsumer.accept(getCookies());
 			return this;
 		}
@@ -378,7 +375,6 @@ class DefaultWebClient implements WebClient {
 
 		private List<StatusHandler> statusHandlers = new ArrayList<>(1);
 
-
 		DefaultResponseSpec(Mono<ClientResponse> responseMono) {
 			this.responseMono = responseMono;
 			this.statusHandlers.add(DEFAULT_STATUS_HANDLER);
@@ -388,13 +384,9 @@ class DefaultWebClient implements WebClient {
 		public ResponseSpec onStatus(Predicate<HttpStatus> statusPredicate,
 				Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
 
-			Assert.notNull(statusPredicate, "'statusPredicate' must not be null");
-			Assert.notNull(exceptionFunction, "'exceptionFunction' must not be null");
-
 			if (this.statusHandlers.size() == 1 && this.statusHandlers.get(0) == DEFAULT_STATUS_HANDLER) {
 				this.statusHandlers.clear();
 			}
-
 			this.statusHandlers.add(new StatusHandler(statusPredicate, exceptionFunction));
 
 			return this;
@@ -476,6 +468,7 @@ class DefaultWebClient implements WebClient {
 					});
 		}
 
+
 		private static class StatusHandler {
 
 			private final Predicate<HttpStatus> predicate;
@@ -484,6 +477,9 @@ class DefaultWebClient implements WebClient {
 
 			public StatusHandler(Predicate<HttpStatus> predicate,
 					Function<ClientResponse, Mono<? extends Throwable>> exceptionFunction) {
+
+				Assert.notNull(predicate, "Predicate must not be null");
+				Assert.notNull(exceptionFunction, "Function must not be null");
 				this.predicate = predicate;
 				this.exceptionFunction = exceptionFunction;
 			}
@@ -496,6 +492,6 @@ class DefaultWebClient implements WebClient {
 				return this.exceptionFunction.apply(response);
 			}
 		}
-
 	}
+
 }

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/DefaultWebClientBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -40,7 +40,7 @@ import org.springframework.web.util.UriBuilderFactory;
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-class DefaultWebClientBuilder implements WebClient.Builder {
+final class DefaultWebClientBuilder implements WebClient.Builder {
 
 	@Nullable
 	private String baseUrl;
@@ -74,7 +74,7 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 	}
 
 	public DefaultWebClientBuilder(DefaultWebClientBuilder other) {
-		Assert.notNull(other, "'other' must not be null");
+		Assert.notNull(other, "DefaultWebClientBuilder must not be null");
 
 		this.baseUrl = other.baseUrl;
 		this.defaultUriVariables = (other.defaultUriVariables != null ?
@@ -125,7 +125,6 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 
 	@Override
 	public WebClient.Builder defaultHeaders(Consumer<HttpHeaders> headersConsumer) {
-		Assert.notNull(headersConsumer, "'headersConsumer' must not be null");
 		headersConsumer.accept(initHeaders());
 		return this;
 	}
@@ -145,7 +144,6 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 
 	@Override
 	public WebClient.Builder defaultCookies(Consumer<MultiValueMap<String, String>> cookiesConsumer) {
-		Assert.notNull(cookiesConsumer, "Cookies consumer must not be null");
 		cookiesConsumer.accept(initCookies());
 		return this;
 	}
@@ -172,7 +170,6 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 
 	@Override
 	public WebClient.Builder filters(Consumer<List<ExchangeFilterFunction>> filtersConsumer) {
-		Assert.notNull(filtersConsumer, "Filters consumer must not be null");
 		filtersConsumer.accept(initFilters());
 		return this;
 	}
@@ -214,7 +211,8 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 			HttpHeaders copy = new HttpHeaders();
 			copy.putAll(original);
 			return HttpHeaders.readOnlyHttpHeaders(copy);
-		} else {
+		}
+		else {
 			return null;
 		}
 	}
@@ -259,8 +257,6 @@ class DefaultWebClientBuilder implements WebClient.Builder {
 
 	@Override
 	public WebClient.Builder apply(Consumer<WebClient.Builder> builderConsumer) {
-		Assert.notNull(builderConsumer, "'builderConsumer' must not be null");
-
 		builderConsumer.accept(this);
 		return this;
 	}

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ExchangeFilterFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -50,7 +50,7 @@ public interface ExchangeFilterFunction {
 	 * {@code after} function
 	 */
 	default ExchangeFilterFunction andThen(ExchangeFilterFunction after) {
-		Assert.notNull(after, "'after' must not be null");
+		Assert.notNull(after, "ExchangeFilterFunction must not be null");
 		return (request, next) -> {
 			ExchangeFunction nextExchange = exchangeRequest -> after.filter(exchangeRequest, next);
 			return filter(request, nextExchange);
@@ -63,7 +63,7 @@ public interface ExchangeFilterFunction {
 	 * @return the filtered exchange function
 	 */
 	default ExchangeFunction apply(ExchangeFunction exchange) {
-		Assert.notNull(exchange, "'exchange' must not be null");
+		Assert.notNull(exchange, "ExchangeFunction must not be null");
 		return request -> this.filter(request, exchange);
 	}
 
@@ -73,10 +73,8 @@ public interface ExchangeFilterFunction {
 	 * @param requestProcessor the request processor
 	 * @return the filter adaptation of the request processor
 	 */
-	static ExchangeFilterFunction ofRequestProcessor(Function<ClientRequest,
-			Mono<ClientRequest>> requestProcessor) {
-
-		Assert.notNull(requestProcessor, "'requestProcessor' must not be null");
+	static ExchangeFilterFunction ofRequestProcessor(Function<ClientRequest, Mono<ClientRequest>> requestProcessor) {
+		Assert.notNull(requestProcessor, "Function must not be null");
 		return (request, next) -> requestProcessor.apply(request).flatMap(next::exchange);
 	}
 
@@ -86,10 +84,8 @@ public interface ExchangeFilterFunction {
 	 * @param responseProcessor the response processor
 	 * @return the filter adaptation of the request processor
 	 */
-	static ExchangeFilterFunction ofResponseProcessor(Function<ClientResponse,
-			Mono<ClientResponse>> responseProcessor) {
-
-		Assert.notNull(responseProcessor, "'responseProcessor' must not be null");
+	static ExchangeFilterFunction ofResponseProcessor(Function<ClientResponse, Mono<ClientResponse>> responseProcessor) {
+		Assert.notNull(responseProcessor, "Function must not be null");
 		return (request, next) -> next.exchange(request).flatMap(responseProcessor);
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ExchangeFilterFunctions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -63,7 +63,6 @@ public abstract class ExchangeFilterFunctions {
 	public static ExchangeFilterFunction basicAuthentication(String username, String password) {
 		Assert.notNull(username, "'username' must not be null");
 		Assert.notNull(password, "'password' must not be null");
-
 		checkIllegalCharacters(username, password);
 		return basicAuthenticationInternal(r -> Optional.of(new Credentials(username, password)));
 	}
@@ -134,8 +133,8 @@ public abstract class ExchangeFilterFunctions {
 	public static ExchangeFilterFunction statusError(Predicate<HttpStatus> statusPredicate,
 			Function<ClientResponse, ? extends Throwable> exceptionFunction) {
 
-		Assert.notNull(statusPredicate, "'statusPredicate' must not be null");
-		Assert.notNull(exceptionFunction, "'exceptionFunction' must not be null");
+		Assert.notNull(statusPredicate, "Predicate must not be null");
+		Assert.notNull(exceptionFunction, "Function must not be null");
 
 		return ExchangeFilterFunction.ofResponseProcessor(
 				clientResponse -> {
@@ -168,7 +167,6 @@ public abstract class ExchangeFilterFunctions {
 		public Credentials(String username, String password) {
 			Assert.notNull(username, "'username' must not be null");
 			Assert.notNull(password, "'password' must not be null");
-
 			this.username = username;
 			this.password = password;
 		}

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/ExchangeFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -18,8 +18,6 @@ package org.springframework.web.reactive.function.client;
 
 import reactor.core.publisher.Mono;
 
-import org.springframework.util.Assert;
-
 /**
  * Represents a function that exchanges a {@linkplain ClientRequest request} for a (delayed)
  * {@linkplain ClientResponse}. Can be used as an alternative to {@link WebClient}.
@@ -55,7 +53,6 @@ public interface ExchangeFunction {
 	 * @see ExchangeFilterFunction#apply(ExchangeFunction)
 	 */
 	default ExchangeFunction filter(ExchangeFilterFunction filter) {
-		Assert.notNull(filter, "'filter' must not be null");
 		return filter.apply(this);
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/WebClient.java

@@ -38,9 +38,9 @@ import org.springframework.http.client.reactive.ClientHttpConnector;
 import org.springframework.http.client.reactive.ClientHttpRequest;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
 import org.springframework.web.util.UriBuilder;
 import org.springframework.web.util.UriBuilderFactory;
-import org.springframework.web.reactive.function.BodyInserters;
 
 /**
  * A non-blocking, reactive client for performing HTTP requests with Reactive

spring-webflux/src/main/java/org/springframework/web/reactive/function/client/support/ClientResponseWrapper.java

@@ -55,7 +55,7 @@ public class ClientResponseWrapper implements ClientResponse {
 	 * @param delegate the response to wrap
 	 */
 	public ClientResponseWrapper(ClientResponse delegate) {
-		Assert.notNull(delegate, "'delegate' must not be null");
+		Assert.notNull(delegate, "Delegate is required");
 		this.delegate = delegate;
 	}
 

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

@@ -64,35 +64,34 @@ class DefaultHandlerStrategiesBuilder implements HandlerStrategies.Builder {
 
 	@Override
 	public HandlerStrategies.Builder codecs(Consumer<ServerCodecConfigurer> consumer) {
-		Assert.notNull(consumer, "'consumer' must not be null");
 		consumer.accept(this.codecConfigurer);
 		return this;
 	}
 
 	@Override
 	public HandlerStrategies.Builder viewResolver(ViewResolver viewResolver) {
-		Assert.notNull(viewResolver, "'viewResolver' must not be null");
+		Assert.notNull(viewResolver, "ViewResolver must not be null");
 		this.viewResolvers.add(viewResolver);
 		return this;
 	}
 
 	@Override
 	public HandlerStrategies.Builder webFilter(WebFilter filter) {
-		Assert.notNull(filter, "'filter' must not be null");
+		Assert.notNull(filter, "WebFilter must not be null");
 		this.webFilters.add(filter);
 		return this;
 	}
 
 	@Override
 	public HandlerStrategies.Builder exceptionHandler(WebExceptionHandler exceptionHandler) {
-		Assert.notNull(exceptionHandler, "'exceptionHandler' must not be null");
+		Assert.notNull(exceptionHandler, "WebExceptionHandler must not be null");
 		this.exceptionHandlers.add(exceptionHandler);
 		return this;
 	}
 
 	@Override
 	public HandlerStrategies.Builder localeContextResolver(LocaleContextResolver localeContextResolver) {
-		Assert.notNull(localeContextResolver, "'localeContextResolver' must not be null");
+		Assert.notNull(localeContextResolver, "LocaleContextResolver must not be null");
 		this.localeContextResolver = localeContextResolver;
 		return this;
 	}

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

@@ -49,7 +49,7 @@ import org.springframework.web.server.ServerWebExchange;
  * @author Juergen Hoeller
  * @since 5.0
  */
-class DefaultRenderingResponseBuilder implements RenderingResponse.Builder {
+final class DefaultRenderingResponseBuilder implements RenderingResponse.Builder {
 
 	private final String name;
 
@@ -63,6 +63,7 @@ class DefaultRenderingResponseBuilder implements RenderingResponse.Builder {
 
 
 	public DefaultRenderingResponseBuilder(RenderingResponse other) {
+		Assert.notNull(other, "RenderingResponse must not be null");
 		this.name = other.name();
 		this.status = (other instanceof DefaultRenderingResponse ?
 				((DefaultRenderingResponse) other).statusCode : other.statusCode().value());
@@ -71,6 +72,7 @@ class DefaultRenderingResponseBuilder implements RenderingResponse.Builder {
 	}
 
 	public DefaultRenderingResponseBuilder(String name) {
+		Assert.notNull(name, "Name must not be null");
 		this.name = name;
 	}
 

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

@@ -43,7 +43,6 @@ import org.springframework.http.codec.multipart.Part;
 import org.springframework.http.server.PathContainer;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
-import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyExtractor;
 import org.springframework.web.reactive.function.BodyExtractors;
@@ -128,7 +127,6 @@ class DefaultServerRequest implements ServerRequest {
 
 	@Override
 	public <T> T body(BodyExtractor<T, ? super ServerHttpRequest> extractor, Map<String, Object> hints) {
-		Assert.notNull(extractor, "'extractor' must not be null");
 		return extractor.extract(request(),
 				new BodyExtractor.Context() {
 					@Override
@@ -279,6 +277,7 @@ class DefaultServerRequest implements ServerRequest {
 		}
 	}
 
+
 	private final class ServerRequestAdapter implements HttpRequest {
 
 		@Override
@@ -297,5 +296,4 @@ class DefaultServerRequest implements ServerRequest {
 		}
 	}
 
-
 }

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

@@ -71,13 +71,15 @@ class DefaultServerResponseBuilder implements ServerResponse.BodyBuilder {
 
 
 	public DefaultServerResponseBuilder(ServerResponse other) {
+		Assert.notNull(other, "ServerResponse must not be null");
 		this.statusCode = (other instanceof AbstractServerResponse ?
 				((AbstractServerResponse) other).statusCode : other.statusCode().value());
 		this.headers.addAll(other.headers());
 	}
 
-	public DefaultServerResponseBuilder(HttpStatus statusCode) {
-		this.statusCode = statusCode.value();
+	public DefaultServerResponseBuilder(HttpStatus status) {
+		Assert.notNull(status, "HttpStatus must not be null");
+		this.statusCode = status.value();
 	}
 
 	public DefaultServerResponseBuilder(int statusCode) {
@@ -406,12 +408,10 @@ class DefaultServerResponseBuilder implements ServerResponse.BodyBuilder {
 				public List<HttpMessageWriter<?>> messageWriters() {
 					return context.messageWriters();
 				}
-
 				@Override
 				public Optional<ServerHttpRequest> serverRequest() {
 					return Optional.of(exchange.getRequest());
 				}
-
 				@Override
 				public Map<String, Object> hints() {
 					return hints;

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -55,7 +55,7 @@ public interface HandlerFilterFunction<T extends ServerResponse, R extends Serve
 	 * {@code after} function
 	 */
 	default HandlerFilterFunction<T, R> andThen(HandlerFilterFunction<T, T> after) {
-		Assert.notNull(after, "'after' must not be null");
+		Assert.notNull(after, "HandlerFilterFunction must not be null");
 		return (request, next) -> {
 			HandlerFunction<T> nextHandler = handlerRequest -> after.filter(handlerRequest, next);
 			return filter(request, nextHandler);
@@ -68,35 +68,34 @@ public interface HandlerFilterFunction<T extends ServerResponse, R extends Serve
 	 * @return the filtered handler function
 	 */
 	default HandlerFunction<R> apply(HandlerFunction<T> handler) {
-		Assert.notNull(handler, "'handler' must not be null");
+		Assert.notNull(handler, "HandlerFunction must not be null");
 		return request -> this.filter(request, handler);
 	}
 
 	/**
-	 * Adapt the given request processor function to a filter function that only operates on the
-	 * {@code ClientRequest}.
+	 * Adapt the given request processor function to a filter function that only operates
+	 * on the {@code ClientRequest}.
 	 * @param requestProcessor the request processor
 	 * @return the filter adaptation of the request processor
 	 */
 	static HandlerFilterFunction<?, ?> ofRequestProcessor(
 			Function<ServerRequest, Mono<ServerRequest>> requestProcessor) {
 
-		Assert.notNull(requestProcessor, "'requestProcessor' must not be null");
+		Assert.notNull(requestProcessor, "Function must not be null");
 		return (request, next) -> requestProcessor.apply(request).flatMap(next::handle);
 	}
 
 	/**
-	 * Adapt the given response processor function to a filter function that only operates on the
-	 * {@code ClientResponse}.
+	 * Adapt the given response processor function to a filter function that only operates
+	 * on the {@code ClientResponse}.
 	 * @param responseProcessor the response processor
 	 * @return the filter adaptation of the request processor
 	 */
 	static <T extends ServerResponse, R extends ServerResponse> HandlerFilterFunction<T, R> ofResponseProcessor(
 			Function<T, Mono<R>> responseProcessor) {
 
-		Assert.notNull(responseProcessor, "'responseProcessor' must not be null");
+		Assert.notNull(responseProcessor, "Function must not be null");
 		return (request, next) -> next.handle(request).flatMap(responseProcessor);
 	}
 
-
 }

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

@@ -27,6 +27,7 @@ import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.UrlResource;
 import org.springframework.http.server.PathContainer;
+import org.springframework.util.Assert;
 import org.springframework.util.ResourceUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.util.pattern.PathPattern;
@@ -48,6 +49,8 @@ class PathResourceLookupFunction implements Function<ServerRequest, Mono<Resourc
 
 
 	public PathResourceLookupFunction(String pattern, Resource location) {
+		Assert.hasLength(pattern, "'pattern' must not be empty");
+		Assert.notNull(location, "'location' must not be null");
 		this.pattern = PATTERN_PARSER.parse(pattern);
 		this.location = location;
 	}

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

@@ -26,7 +26,6 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseCookie;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 
 /**
@@ -57,7 +56,6 @@ public interface RenderingResponse extends ServerResponse {
 	 * @return the created builder
 	 */
 	static Builder from(RenderingResponse other) {
-		Assert.notNull(other, "Other RenderingResponse must not be null");
 		return new DefaultRenderingResponseBuilder(other);
 	}
 
@@ -67,7 +65,6 @@ public interface RenderingResponse extends ServerResponse {
 	 * @return the created builder
 	 */
 	static Builder create(String name) {
-		Assert.notNull(name, "'name' must not be null");
 		return new DefaultRenderingResponseBuilder(name);
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -18,8 +18,6 @@ package org.springframework.web.reactive.function.server;
 
 import java.util.Optional;
 
-import org.springframework.util.Assert;
-
 /**
  * Represents a function that evaluates on a given {@link ServerRequest}.
  * Instances of this function that evaluate on common request properties
@@ -49,7 +47,6 @@ public interface RequestPredicate {
 	 * @return a predicate composed of this predicate AND the {@code other} predicate
 	 */
 	default RequestPredicate and(RequestPredicate other) {
-		Assert.notNull(other, "'other' must not be null");
 		return new RequestPredicates.AndRequestPredicate(this, other);
 	}
 
@@ -69,7 +66,6 @@ public interface RequestPredicate {
 	 * @return a predicate composed of this predicate OR the {@code other} predicate
 	 */
 	default RequestPredicate or(RequestPredicate other) {
-		Assert.notNull(other, "'other' must not be null");
 		return new RequestPredicates.OrRequestPredicate(this, other);
 	}
 

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

@@ -316,7 +316,7 @@ public abstract class RequestPredicates {
 		private final HttpMethod httpMethod;
 
 		public HttpMethodPredicate(HttpMethod httpMethod) {
-			Assert.notNull(httpMethod, "'httpMethod' must not be null");
+			Assert.notNull(httpMethod, "HttpMethod must not be null");
 			this.httpMethod = httpMethod;
 		}
 
@@ -388,7 +388,7 @@ public abstract class RequestPredicates {
 		private final Predicate<ServerRequest.Headers> headersPredicate;
 
 		public HeadersPredicate(Predicate<ServerRequest.Headers> headersPredicate) {
-			Assert.notNull(headersPredicate, "'headersPredicate' must not be null");
+			Assert.notNull(headersPredicate, "Predicate must not be null");
 			this.headersPredicate = headersPredicate;
 		}
 
@@ -410,13 +410,15 @@ public abstract class RequestPredicates {
 		private final RequestPredicate right;
 
 		public AndRequestPredicate(RequestPredicate left, RequestPredicate right) {
+			Assert.notNull(left, "Left RequestPredicate must not be null");
+			Assert.notNull(right, "Right RequestPredicate must not be null");
 			this.left = left;
 			this.right = right;
 		}
 
 		@Override
 		public boolean test(ServerRequest t) {
-			return this.left.test(t) && this.right.test(t);
+			return (this.left.test(t) && this.right.test(t));
 		}
 
 		@Override
@@ -437,12 +439,15 @@ public abstract class RequestPredicates {
 		private final RequestPredicate right;
 
 		public OrRequestPredicate(RequestPredicate left, RequestPredicate right) {
+			Assert.notNull(left, "Left RequestPredicate must not be null");
+			Assert.notNull(right, "Right RequestPredicate must not be null");
 			this.left = left;
 			this.right = right;
 		}
+
 		@Override
 		public boolean test(ServerRequest t) {
-			return this.left.test(t) || this.right.test(t);
+			return (this.left.test(t) || this.right.test(t));
 		}
 
 		@Override

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -83,11 +83,8 @@ public abstract class RouterFunctions {
 	 * {@code predicate} evaluates to {@code true}
 	 * @see RequestPredicates
 	 */
-	public static <T extends ServerResponse> RouterFunction<T> route(RequestPredicate predicate,
-			HandlerFunction<T> handlerFunction) {
-
-		Assert.notNull(predicate, "'predicate' must not be null");
-		Assert.notNull(handlerFunction, "'handlerFunction' must not be null");
+	public static <T extends ServerResponse> RouterFunction<T> route(
+			RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 
 		return new DefaultRouterFunction<>(predicate, handlerFunction);
 	}
@@ -115,11 +112,8 @@ public abstract class RouterFunctions {
 	 * {@code predicate} evaluates to {@code true}
 	 * @see RequestPredicates
 	 */
-	public static <T extends ServerResponse> RouterFunction<T> nest(RequestPredicate predicate,
-			RouterFunction<T> routerFunction) {
-
-		Assert.notNull(predicate, "'predicate' must not be null");
-		Assert.notNull(routerFunction, "'routerFunction' must not be null");
+	public static <T extends ServerResponse> RouterFunction<T> nest(
+			RequestPredicate predicate, RouterFunction<T> routerFunction) {
 
 		return new DefaultNestedRouterFunction<>(predicate, routerFunction);
 	}
@@ -136,8 +130,6 @@ public abstract class RouterFunctions {
 	 * @return a router function that routes to resources
 	 */
 	public static RouterFunction<ServerResponse> resources(String pattern, Resource location) {
-		Assert.hasLength(pattern, "'pattern' must not be empty");
-		Assert.notNull(location, "'location' must not be null");
 		return resources(new PathResourceLookupFunction(pattern, location));
 	}
 
@@ -149,7 +141,6 @@ public abstract class RouterFunctions {
 	 * @return a router function that routes to resources
 	 */
 	public static RouterFunction<ServerResponse> resources(Function<ServerRequest, Mono<Resource>> lookupFunction) {
-		Assert.notNull(lookupFunction, "'lookupFunction' must not be null");
 		return new ResourcesRouterFunction(lookupFunction);
 	}
 
@@ -192,9 +183,6 @@ public abstract class RouterFunctions {
 	 * @return an http handler that handles HTTP request using the given router function
 	 */
 	public static HttpHandler toHttpHandler(RouterFunction<?> routerFunction, HandlerStrategies strategies) {
-		Assert.notNull(routerFunction, "RouterFunction must not be null");
-		Assert.notNull(strategies, "HandlerStrategies must not be null");
-
 		WebHandler webHandler = toWebHandler(routerFunction, strategies);
 		return WebHttpHandlerBuilder.webHandler(webHandler)
 				.filters(filters -> filters.addAll(strategies.webFilters()))
@@ -396,8 +384,9 @@ public abstract class RouterFunctions {
 
 		private final HandlerFunction<T> handlerFunction;
 
-		public DefaultRouterFunction(RequestPredicate predicate,
-				HandlerFunction<T> handlerFunction) {
+		public DefaultRouterFunction(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
+			Assert.notNull(predicate, "Predicate must not be null");
+			Assert.notNull(handlerFunction, "HandlerFunction must not be null");
 			this.predicate = predicate;
 			this.handlerFunction = handlerFunction;
 		}
@@ -406,8 +395,7 @@ public abstract class RouterFunctions {
 		public Mono<HandlerFunction<T>> route(ServerRequest request) {
 			if (this.predicate.test(request)) {
 				if (logger.isDebugEnabled()) {
-					logger.debug(String.format("Predicate \"%s\" matches against \"%s\"",
-							this.predicate, request));
+					logger.debug(String.format("Predicate \"%s\" matches against \"%s\"", this.predicate, request));
 				}
 				return Mono.just(this.handlerFunction);
 			}
@@ -430,8 +418,9 @@ public abstract class RouterFunctions {
 
 		private final RouterFunction<T> routerFunction;
 
-		public DefaultNestedRouterFunction(RequestPredicate predicate,
-				RouterFunction<T> routerFunction) {
+		public DefaultNestedRouterFunction(RequestPredicate predicate, RouterFunction<T> routerFunction) {
+			Assert.notNull(predicate, "Predicate must not be null");
+			Assert.notNull(routerFunction, "RouterFunction must not be null");
 			this.predicate = predicate;
 			this.routerFunction = routerFunction;
 		}
@@ -466,6 +455,7 @@ public abstract class RouterFunctions {
 		private final Function<ServerRequest, Mono<Resource>> lookupFunction;
 
 		public ResourcesRouterFunction(Function<ServerRequest, Mono<Resource>> lookupFunction) {
+			Assert.notNull(lookupFunction, "Function must not be null");
 			this.lookupFunction = lookupFunction;
 		}
 

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

@@ -38,7 +38,6 @@ import org.springframework.http.ResponseCookie;
 import org.springframework.http.codec.HttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2CodecSupport;
 import org.springframework.http.server.reactive.ServerHttpResponse;
-import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyInserter;
 import org.springframework.web.reactive.function.BodyInserters;
@@ -91,7 +90,6 @@ public interface ServerResponse {
 	 * @return the created builder
 	 */
 	static BodyBuilder from(ServerResponse other) {
-		Assert.notNull(other, "Other ServerResponse must not be null");
 		return new DefaultServerResponseBuilder(other);
 	}
 
@@ -101,7 +99,6 @@ public interface ServerResponse {
 	 * @return the created builder
 	 */
 	static BodyBuilder status(HttpStatus status) {
-		Assert.notNull(status, "HttpStatus must not be null");
 		return new DefaultServerResponseBuilder(status);
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -26,7 +26,6 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.ServerCodecConfigurer;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.web.reactive.function.server.RouterFunction;
 import org.springframework.web.reactive.function.server.RouterFunctions;
@@ -87,7 +86,6 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 	 * <p>By default this is set to the {@link ServerCodecConfigurer}'s defaults.
 	 */
 	public void setMessageReaders(List<HttpMessageReader<?>> messageReaders) {
-		Assert.notNull(messageReaders, "'messageReaders' must not be null");
 		this.messageReaders = messageReaders;
 	}
 

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

@@ -201,6 +201,7 @@ public class ServerRequestWrapper implements ServerRequest {
 		return this.delegate.multipartData();
 	}
 
+
 	/**
 	 * Implementation of the {@code Headers} interface that can be subclassed
 	 * to adapt the headers in a
@@ -211,17 +212,15 @@ public class ServerRequestWrapper implements ServerRequest {
 
 		private final Headers headers;
 
-
 		/**
 		 * Create a new {@code HeadersWrapper} that wraps the given request.
 		 * @param headers the headers to wrap
 		 */
 		public HeadersWrapper(Headers headers) {
-			Assert.notNull(headers, "'headers' must not be null");
+			Assert.notNull(headers, "Headers must not be null");
 			this.headers = headers;
 		}
 
-
 		@Override
 		public List<MediaType> accept() {
 			return this.headers.accept();

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

@@ -53,7 +53,6 @@ public class ServerResponseResultHandler implements HandlerResultHandler, Initia
 	 * <p>By default this is set to {@link ServerCodecConfigurer}'s default writers.
 	 */
 	public void setMessageWriters(List<HttpMessageWriter<?>> configurer) {
-		Assert.notNull(messageWriters, "'messageWriters' must not be null");
 		this.messageWriters = configurer;
 	}
 
@@ -104,4 +103,5 @@ public class ServerResponseResultHandler implements HandlerResultHandler, Initia
 			}
 		});
 	}
+
 }