Add WebExchangeDataBinder

Issue: SPR-14541

spring-web/src/main/java/org/springframework/web/bind/WebExchangeDataBinder.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2002-2016 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.bind;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.MutablePropertyValues;
+import org.springframework.core.ResolvableType;
+import org.springframework.http.MediaType;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.server.ServerWebExchange;
+
+/**
+ * Specialized {@link org.springframework.validation.DataBinder} to perform data
+ * binding from URL query params or form data in the request data to Java objects.
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.0
+ */
+public class WebExchangeDataBinder extends WebDataBinder {
+
+	private static final ResolvableType MULTIVALUE_MAP_TYPE = ResolvableType.forClass(MultiValueMap.class);
+
+
+	private HttpMessageReader<MultiValueMap<String, String>> formReader = null;
+
+
+	/**
+	 * Create a new instance, with default object name.
+	 * @param target the target object to bind onto (or {@code null} if the
+	 * binder is just used to convert a plain parameter value)
+	 * @see #DEFAULT_OBJECT_NAME
+	 */
+	public WebExchangeDataBinder(Object target) {
+		super(target);
+	}
+
+	/**
+	 * Create a new instance.
+	 * @param target the target object to bind onto (or {@code null} if the
+	 * binder is just used to convert a plain parameter value)
+	 * @param objectName the name of the target object
+	 */
+	public WebExchangeDataBinder(Object target, String objectName) {
+		super(target, objectName);
+	}
+
+
+	public void setFormReader(HttpMessageReader<MultiValueMap<String, String>> formReader) {
+		this.formReader = formReader;
+	}
+
+	public HttpMessageReader<MultiValueMap<String, String>> getFormReader() {
+		return this.formReader;
+	}
+
+
+	/**
+	 * Bind the URL query parameters or form data of the body of the given request
+	 * to this binder's target. The request body is parsed if the content-type
+	 * is "application/x-www-form-urlencoded".
+	 *
+	 * @param exchange the current exchange.
+	 * @return a {@code Mono<Void>} to indicate the result
+	 */
+	public Mono<Void> bind(ServerWebExchange exchange) {
+
+		ServerHttpRequest request = exchange.getRequest();
+		Mono<MultiValueMap<String, String>> queryParams = Mono.just(request.getQueryParams());
+		Mono<MultiValueMap<String, String>> formParams = getFormParams(exchange);
+
+		return Mono.zip(this::mergeParams, queryParams, formParams)
+				.map(this::getParamsToBind)
+				.doOnNext(values -> values.putAll(getMultipartFiles(exchange)))
+				.doOnNext(values -> values.putAll(getExtraValuesToBind(exchange)))
+				.then(values -> {
+					doBind(new MutablePropertyValues(values));
+					return Mono.empty();
+				});
+	}
+
+	private Mono<MultiValueMap<String, String>> getFormParams(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		MediaType contentType = request.getHeaders().getContentType();
+		if (this.formReader.canRead(MULTIVALUE_MAP_TYPE, contentType)) {
+			return this.formReader.readMono(MULTIVALUE_MAP_TYPE, request, Collections.emptyMap());
+		}
+		else {
+			return Mono.just(new LinkedMultiValueMap<>());
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private MultiValueMap<String, String> mergeParams(Object[] paramMaps) {
+		MultiValueMap<String, String> result = new LinkedMultiValueMap<>();
+		Arrays.stream(paramMaps).forEach(map -> result.putAll((MultiValueMap<String, String>) map));
+		return result;
+	}
+
+	private Map<String, Object> getParamsToBind(MultiValueMap<String, String> params) {
+		Map<String, Object> valuesToBind = new TreeMap<>();
+		for (Map.Entry<String, List<String>> entry : params.entrySet()) {
+			String name = entry.getKey();
+			List<String> values = entry.getValue();
+			if (values == null || values.isEmpty()) {
+				// Do nothing, no values found at all.
+			}
+			else {
+				if (values.size() > 1) {
+					valuesToBind.put(name, values);
+				}
+				else {
+					valuesToBind.put(name, values.get(0));
+				}
+			}
+		}
+		return valuesToBind;
+	}
+
+	/**
+	 * Bind all multipart files contained in the given request, if any (in case
+	 * of a multipart request).
+	 * <p>Multipart files will only be added to the property values if they
+	 * are not empty or if we're configured to bind empty multipart files too.
+	 * @param exchange the current exchange
+	 * @return Map of field name String to MultipartFile object
+	 */
+	protected Map<String, List<MultipartFile>> getMultipartFiles(ServerWebExchange exchange) {
+		// TODO
+		return Collections.emptyMap();
+	}
+
+	/**
+	 * Extension point that subclasses can use to add extra bind values for a
+	 * request. Invoked before {@link #doBind(MutablePropertyValues)}.
+	 * The default implementation is empty.
+	 * @param exchange the current exchange
+	 */
+	protected Map<String, ?> getExtraValuesToBind(ServerWebExchange exchange) {
+		return Collections.emptyMap();
+	}
+
+}

spring-web/src/main/java/org/springframework/web/bind/support/ConfigurableWebBindingInitializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -22,7 +22,6 @@ import org.springframework.validation.BindingErrorProcessor;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
 import org.springframework.web.bind.WebDataBinder;
-import org.springframework.web.context.request.WebRequest;
 
 /**
  * Convenient {@link WebBindingInitializer} for declarative configuration
@@ -182,7 +181,7 @@ public class ConfigurableWebBindingInitializer implements WebBindingInitializer
 
 
 	@Override
-	public void initBinder(WebDataBinder binder, WebRequest request) {
+	public void initBinder(WebDataBinder binder) {
 		binder.setAutoGrowNestedPaths(this.autoGrowNestedPaths);
 		if (this.directFieldAccess) {
 			binder.initDirectFieldAccess();

spring-web/src/main/java/org/springframework/web/bind/support/DefaultDataBinderFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -47,6 +47,7 @@ public class DefaultDataBinderFactory implements WebDataBinderFactory {
 	 * @throws Exception in case of invalid state or arguments
 	 */
 	@Override
+	@SuppressWarnings("deprecation")
 	public final WebDataBinder createBinder(NativeWebRequest webRequest, Object target, String objectName)
 			throws Exception {
 
@@ -74,7 +75,7 @@ public class DefaultDataBinderFactory implements WebDataBinderFactory {
 
 	/**
 	 * Extension point to further initialize the created data binder instance
-	 * (e.g. with {@code @InitBinder} methods) after "global" initializaton
+	 * (e.g. with {@code @InitBinder} methods) after "global" initialization
 	 * via {@link WebBindingInitializer}.
 	 * @param dataBinder the data binder instance to customize
 	 * @param webRequest the current request

spring-web/src/main/java/org/springframework/web/bind/support/WebBindingInitializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -20,19 +20,31 @@ import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.context.request.WebRequest;
 
 /**
- * Callback interface for initializing a {@link org.springframework.web.bind.WebDataBinder}
- * for performing data binding in the context of a specific web request.
+ * Callback interface for initializing a {@link WebDataBinder} for performing
+ * data binding in the context of a specific web request.
  *
  * @author Juergen Hoeller
+ * @author Rossen Stoyanchev
  * @since 2.5
  */
 public interface WebBindingInitializer {
 
 	/**
-	 * Initialize the given DataBinder for the given request.
+	 * Initialize the given DataBinder.
+	 * @param binder the DataBinder to initialize
+	 * @since 5.0
+	 */
+	void initBinder(WebDataBinder binder);
+
+	/**
+	 * Initialize the given DataBinder for the given (Servlet) request.
 	 * @param binder the DataBinder to initialize
 	 * @param request the web request that the data binding happens within
+	 * @deprecated as of 5.0 in favor of {@link #initBinder(WebDataBinder)}
 	 */
-	void initBinder(WebDataBinder binder, WebRequest request);
+	@Deprecated
+	default void initBinder(WebDataBinder binder, WebRequest request) {
+		initBinder(binder);
+	}
 
 }