Add ArgumentResolverConfigurer

Replace the List<HandlerMethodArgumentResolver> with a dedicated
configurer that currently has one method accepting custom resolver
registrations.

spring-webflux/src/main/java/org/springframework/web/reactive/config/DelegatingWebFluxConfiguration.java

@@ -26,7 +26,7 @@ import org.springframework.util.CollectionUtils;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolverBuilder;
-import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
+import org.springframework.web.reactive.result.method.annotation.ArgumentResolverConfigurer;
 
 /**
  * A subclass of {@code WebFluxConfigurationSupport} that detects and delegates
@@ -70,8 +70,8 @@ public class DelegatingWebFluxConfiguration extends WebFluxConfigurationSupport
 	}
 
 	@Override
-	protected void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+	protected void configureArgumentResolvers(ArgumentResolverConfigurer configurer) {
-		this.configurers.addArgumentResolvers(resolvers);
+		this.configurers.configureArgumentResolvers(configurer);
 	}
 
 	@Override

spring-webflux/src/main/java/org/springframework/web/reactive/config/WebFluxConfigurationSupport.java

@@ -16,7 +16,6 @@
 
 package org.springframework.web.reactive.config;
 
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -50,7 +49,7 @@ import org.springframework.web.reactive.accept.CompositeContentTypeResolver;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolverBuilder;
 import org.springframework.web.reactive.handler.AbstractHandlerMapping;
 import org.springframework.web.reactive.result.SimpleHandlerAdapter;
-import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
+import org.springframework.web.reactive.result.method.annotation.ArgumentResolverConfigurer;
 import org.springframework.web.reactive.result.method.annotation.RequestMappingHandlerAdapter;
 import org.springframework.web.reactive.result.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.reactive.result.method.annotation.ResponseBodyResultHandler;
@@ -240,11 +239,9 @@ public class WebFluxConfigurationSupport implements ApplicationContextAware {
 		adapter.setWebBindingInitializer(getConfigurableWebBindingInitializer());
 		adapter.setReactiveAdapterRegistry(webFluxAdapterRegistry());
 
-		List<HandlerMethodArgumentResolver> resolvers = new ArrayList<>();
+		ArgumentResolverConfigurer configurer = new ArgumentResolverConfigurer();
-		addArgumentResolvers(resolvers);
+		configureArgumentResolvers(configurer);
-		if (!resolvers.isEmpty()) {
+		adapter.setArgumentResolverConfigurer(configurer);
-			adapter.setCustomArgumentResolvers(resolvers);
-		}
 
 		return adapter;
 	}
@@ -257,9 +254,9 @@ public class WebFluxConfigurationSupport implements ApplicationContextAware {
 	}
 
 	/**
-	 * Provide custom argument resolvers without overriding the built-in ones.
+	 * Configure resolvers for custom controller method arguments.
 	 */
-	protected void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+	protected void configureArgumentResolvers(ArgumentResolverConfigurer configurer) {
 	}
 
 	/**

spring-webflux/src/main/java/org/springframework/web/reactive/config/WebFluxConfigurer.java

@@ -29,6 +29,7 @@ import org.springframework.web.reactive.accept.CompositeContentTypeResolver;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolver;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolverBuilder;
 import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
+import org.springframework.web.reactive.result.method.annotation.ArgumentResolverConfigurer;
 
 /**
  * Defines callback methods to customize the configuration for Web Reactive
@@ -80,11 +81,10 @@ public interface WebFluxConfigurer {
 	}
 
 	/**
-	 * Provide custom controller method argument resolvers. Such resolvers do
+	 * Configure resolvers for custom controller method arguments.
-	 * not override and will be invoked after the built-in ones.
+	 * @param configurer to configurer to use
-	 * @param resolvers a list of resolvers to add
 	 */
-	default void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+	default void configureArgumentResolvers(ArgumentResolverConfigurer configurer) {
 	}
 
 	/**

spring-webflux/src/main/java/org/springframework/web/reactive/config/WebFluxConfigurerComposite.java

@@ -28,7 +28,7 @@ import org.springframework.util.CollectionUtils;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolverBuilder;
-import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
+import org.springframework.web.reactive.result.method.annotation.ArgumentResolverConfigurer;
 
 /**
  * A {@link WebFluxConfigurer} that delegates to one or more others.
@@ -70,8 +70,8 @@ public class WebFluxConfigurerComposite implements WebFluxConfigurer {
 	}
 
 	@Override
-	public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+	public void configureArgumentResolvers(ArgumentResolverConfigurer configurer) {
-		this.delegates.forEach(delegate -> delegate.addArgumentResolvers(resolvers));
+		this.delegates.forEach(delegate -> delegate.configureArgumentResolvers(configurer));
 	}
 
 	@Override

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ArgumentResolverConfigurer.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2002-2017 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
+ *
+ *      http://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.result.method.annotation;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.util.Assert;
+import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
+
+/**
+ * Helps to configure resolvers for Controller method arguments.
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.0
+ */
+public class ArgumentResolverConfigurer {
+
+	private final List<HandlerMethodArgumentResolver> customResolvers = new ArrayList<>(8);
+
+
+	/**
+	 * Configure resolvers for custom controller method arguments.
+	 * @param resolver the resolver(s) to add
+	 */
+	public void addCustomResolver(HandlerMethodArgumentResolver... resolver) {
+		Assert.notNull(resolver, "'resolvers' must not be null");
+		this.customResolvers.addAll(Arrays.asList(resolver));
+	}
+
+
+	List<HandlerMethodArgumentResolver> getCustomResolvers() {
+		return this.customResolvers;
+	}
+
+}

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ControllerMethodResolver.java

@@ -17,6 +17,7 @@ package org.springframework.web.reactive.result.method.annotation;
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -95,34 +96,36 @@ class ControllerMethodResolver {
 			new LinkedHashMap<>(64);
 
 
-	ControllerMethodResolver(List<HandlerMethodArgumentResolver> customResolvers,
+	ControllerMethodResolver(ArgumentResolverConfigurer argumentResolverConfigurer,
 			List<HttpMessageReader<?>> messageReaders, ReactiveAdapterRegistry reactiveRegistry,
 			ConfigurableApplicationContext applicationContext) {
 
-		Assert.notNull(customResolvers, "'customResolvers' should not be null");
+		Assert.notNull(argumentResolverConfigurer, "ArgumentResolverConfigurer is required");
 		Assert.notNull(reactiveRegistry, "ReactiveAdapterRegistry is required");
 		Assert.notNull(applicationContext, "ConfigurableApplicationContext is required");
 
-		ResolverRegistrar registrar = ResolverRegistrar.customResolvers(customResolvers).basic();
+		ArgumentResolverRegistrar registrar;
+
+		registrar= ArgumentResolverRegistrar.configurer(argumentResolverConfigurer).basic();
 		addResolversTo(registrar, reactiveRegistry, applicationContext);
 		this.initBinderResolvers = registrar.getSyncResolvers();
 
-		registrar = ResolverRegistrar.customResolvers(customResolvers).modelAttributeSupport();
+		registrar = ArgumentResolverRegistrar.configurer(argumentResolverConfigurer).modelAttributeSupport();
 		addResolversTo(registrar, reactiveRegistry, applicationContext);
 		this.modelAttributeResolvers = registrar.getResolvers();
 
-		registrar = ResolverRegistrar.customResolvers(customResolvers).fullSupport(messageReaders);
+		registrar = ArgumentResolverRegistrar.configurer(argumentResolverConfigurer).fullSupport(messageReaders);
 		addResolversTo(registrar, reactiveRegistry, applicationContext);
 		this.requestMappingResolvers = registrar.getResolvers();
 
-		registrar = ResolverRegistrar.customResolvers(customResolvers).basic();
+		registrar = ArgumentResolverRegistrar.configurer(argumentResolverConfigurer).basic();
 		addResolversTo(registrar, reactiveRegistry, applicationContext);
 		this.exceptionHandlerResolvers = registrar.getResolvers();
 
 		initControllerAdviceCaches(applicationContext);
 	}
 
-	private void addResolversTo(ResolverRegistrar registrar,
+	private void addResolversTo(ArgumentResolverRegistrar registrar,
 			ReactiveAdapterRegistry reactiveRegistry, ConfigurableApplicationContext context) {
 
 		ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
@@ -319,7 +322,7 @@ class ControllerMethodResolver {
 					(AnnotationUtils.findAnnotation(method, ModelAttribute.class) != null);
 
 
-	private static class ResolverRegistrar {
+	private static class ArgumentResolverRegistrar {
 
 		private final List<HandlerMethodArgumentResolver> customResolvers;
 
@@ -330,10 +333,10 @@ class ControllerMethodResolver {
 		private final List<HandlerMethodArgumentResolver> result = new ArrayList<>();
 
 
-		private ResolverRegistrar(List<HandlerMethodArgumentResolver> customResolvers,
+		private ArgumentResolverRegistrar(ArgumentResolverConfigurer configurer,
 				List<HttpMessageReader<?>> messageReaders, boolean modelAttribute) {
 
-			this.customResolvers = new ArrayList<>(customResolvers);
+			this.customResolvers = configurer.getCustomResolvers();
 			this.messageReaders = messageReaders != null ? new ArrayList<>(messageReaders) : null;
 			this.modelAttributeSupported = modelAttribute;
 		}
@@ -372,32 +375,32 @@ class ControllerMethodResolver {
 		}
 
 
-		public static Builder customResolvers(List<HandlerMethodArgumentResolver> customResolvers) {
+		public static Builder configurer(ArgumentResolverConfigurer configurer) {
-			return new Builder(customResolvers);
+			return new Builder(configurer);
 		}
 
 
 		public static class Builder {
 
-			private final List<HandlerMethodArgumentResolver> customResolvers;
+			private final ArgumentResolverConfigurer configurer;
 
 
-			public Builder(List<HandlerMethodArgumentResolver> customResolvers) {
+			public Builder(ArgumentResolverConfigurer configurer) {
-				this.customResolvers = new ArrayList<>(customResolvers);
+				this.configurer = configurer;
 			}
 
 
-			public ResolverRegistrar fullSupport(List<HttpMessageReader<?>> readers) {
+			public ArgumentResolverRegistrar fullSupport(List<HttpMessageReader<?>> readers) {
 				Assert.notEmpty(readers, "No message readers");
-				return new ResolverRegistrar(this.customResolvers, readers, true);
+				return new ArgumentResolverRegistrar(this.configurer, readers, true);
 			}
 
-			public ResolverRegistrar modelAttributeSupport() {
+			public ArgumentResolverRegistrar modelAttributeSupport() {
-				return new ResolverRegistrar(this.customResolvers, null, true);
+				return new ArgumentResolverRegistrar(this.configurer, null, true);
 			}
 
-			public ResolverRegistrar basic() {
+			public ArgumentResolverRegistrar basic() {
-				return new ResolverRegistrar(this.customResolvers, null, false);
+				return new ArgumentResolverRegistrar(this.configurer, null, false);
 			}
 		}
 

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/RequestMappingHandlerAdapter.java

@@ -25,7 +25,6 @@ import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -44,7 +43,6 @@ import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.reactive.BindingContext;
 import org.springframework.web.reactive.HandlerAdapter;
 import org.springframework.web.reactive.HandlerResult;
-import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver;
 import org.springframework.web.reactive.result.method.InvocableHandlerMethod;
 import org.springframework.web.server.ServerWebExchange;
 
@@ -63,9 +61,9 @@ public class RequestMappingHandlerAdapter implements HandlerAdapter, Application
 
 	private WebBindingInitializer webBindingInitializer;
 
-	private ReactiveAdapterRegistry reactiveAdapterRegistry = new ReactiveAdapterRegistry();
+	private ArgumentResolverConfigurer argumentResolverConfigurer;
 
-	private final List<HandlerMethodArgumentResolver> customArgumentResolvers = new ArrayList<>(8);
+	private ReactiveAdapterRegistry reactiveAdapterRegistry;
 
 	private ConfigurableApplicationContext applicationContext;
 
@@ -117,6 +115,21 @@ public class RequestMappingHandlerAdapter implements HandlerAdapter, Application
 		return this.webBindingInitializer;
 	}
 
+	/**
+	 * Configure resolvers for controller method arguments.
+	 */
+	public void setArgumentResolverConfigurer(ArgumentResolverConfigurer configurer) {
+		Assert.notNull(configurer, "ArgumentResolverConfigurer is required");
+		this.argumentResolverConfigurer = configurer;
+	}
+
+	/**
+	 * Return the configured resolvers for controller method arguments.
+	 */
+	public ArgumentResolverConfigurer getArgumentResolverConfigurer() {
+		return this.argumentResolverConfigurer;
+	}
+
 	/**
 	 * Configure the registry for adapting various reactive types.
 	 * <p>By default this is an instance of {@link ReactiveAdapterRegistry} with
@@ -133,21 +146,6 @@ public class RequestMappingHandlerAdapter implements HandlerAdapter, Application
 		return this.reactiveAdapterRegistry;
 	}
 
-	/**
-	 * Configure resolvers for custom controller method arguments.
-	 */
-	public void setCustomArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
-		this.customArgumentResolvers.clear();
-		this.customArgumentResolvers.addAll(resolvers);
-	}
-
-	/**
-	 * Return the configured custom argument resolvers.
-	 */
-	public List<HandlerMethodArgumentResolver> getCustomArgumentResolvers() {
-		return this.customArgumentResolvers;
-	}
-
 	/**
 	 * A {@link ConfigurableApplicationContext} is expected for resolving
 	 * expressions in method argument default values as well as for
@@ -164,18 +162,22 @@ public class RequestMappingHandlerAdapter implements HandlerAdapter, Application
 		return this.applicationContext;
 	}
 
-	public ConfigurableBeanFactory getBeanFactory() {
-		return this.applicationContext.getBeanFactory();
-	}
-
 
 	@Override
 	public void afterPropertiesSet() throws Exception {
 
-		this.methodResolver = new ControllerMethodResolver(getCustomArgumentResolvers(),
+		if (this.argumentResolverConfigurer == null) {
-				getMessageReaders(), getReactiveAdapterRegistry(), getApplicationContext());
+			this.argumentResolverConfigurer = new ArgumentResolverConfigurer();
+		}
 
-		this.modelInitializer = new ModelInitializer(getReactiveAdapterRegistry());
+		if (this.reactiveAdapterRegistry == null) {
+			this.reactiveAdapterRegistry = new ReactiveAdapterRegistry();
+		}
+
+		this.methodResolver = new ControllerMethodResolver(this.argumentResolverConfigurer,
+				this.messageReaders, this.reactiveAdapterRegistry, this.applicationContext);
+
+		this.modelInitializer = new ModelInitializer(this.reactiveAdapterRegistry);
 	}
 
 

spring-webflux/src/test/java/org/springframework/web/reactive/config/DelegatingWebFluxConfigurationTests.java

@@ -100,7 +100,7 @@ public class DelegatingWebFluxConfigurationTests {
 		verify(webFluxConfigurer).getValidator();
 		verify(webFluxConfigurer).getMessageCodesResolver();
 		verify(webFluxConfigurer).addFormatters(formatterRegistry.capture());
-		verify(webFluxConfigurer).addArgumentResolvers(any());
+		verify(webFluxConfigurer).configureArgumentResolvers(any());
 
 		assertSame(formatterRegistry.getValue(), initializerConversionService);
 		assertEquals(9, codecsConfigurer.getValue().getReaders().size());

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/ControllerMethodResolverTests.java

@@ -67,8 +67,9 @@ public class ControllerMethodResolverTests {
 	@Before
 	public void setUp() throws Exception {
 
-		List<HandlerMethodArgumentResolver> customResolvers =
+		ArgumentResolverConfigurer configurer = new ArgumentResolverConfigurer();
-				Arrays.asList(new CustomArgumentResolver(), new CustomSyncArgumentResolver());
+		configurer.addCustomResolver(new CustomArgumentResolver());
+		configurer.addCustomResolver(new CustomSyncArgumentResolver());
 
 		List<HttpMessageReader<?>> messageReaders = Arrays.asList(
 				new DecoderHttpMessageReader<>(new ByteArrayDecoder()),
@@ -79,7 +80,7 @@ public class ControllerMethodResolverTests {
 		applicationContext.refresh();
 
 		this.methodResolver = new ControllerMethodResolver(
-				customResolvers, messageReaders, new ReactiveAdapterRegistry(), applicationContext);
+				configurer, messageReaders, new ReactiveAdapterRegistry(), applicationContext);
 
 		Method method = ResolvableMethod.on(TestController.class).mockCall(TestController::handle).method();
 		this.handlerMethod = new HandlerMethod(new TestController(), method);