org.springframework.web.reactive.BindingContext Maven / Gradle / Ivy
/*
* 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;
import java.lang.annotation.Annotation;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import reactor.core.publisher.Mono;
import org.springframework.beans.BeanUtils;
import org.springframework.core.MethodParameter;
import org.springframework.core.ReactiveAdapterRegistry;
import org.springframework.core.ResolvableType;
import org.springframework.lang.Nullable;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.DataBinder;
import org.springframework.validation.SmartValidator;
import org.springframework.validation.support.BindingAwareConcurrentModel;
import org.springframework.web.bind.support.BindParamNameResolver;
import org.springframework.web.bind.support.WebBindingInitializer;
import org.springframework.web.bind.support.WebExchangeDataBinder;
import org.springframework.web.server.ServerErrorException;
import org.springframework.web.server.ServerWebExchange;
/**
* Context to assist with binding request data onto Objects and provide access
* to a shared {@link Model} with controller-specific attributes.
*
* Provides methods to create a {@link WebExchangeDataBinder} for a specific
* target, command Object to apply data binding and validation to, or without a
* target Object for simple type conversion from request values.
*
*
Container for the default model for the request.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 5.0
*/
public class BindingContext {
@Nullable
private final WebBindingInitializer initializer;
private final Model model = new BindingAwareConcurrentModel();
private boolean methodValidationApplicable;
private final ReactiveAdapterRegistry reactiveAdapterRegistry;
/**
* Create an instance without an initializer.
*/
public BindingContext() {
this(null);
}
/**
* Create an instance with the given initializer, which may be {@code null}.
*/
public BindingContext(@Nullable WebBindingInitializer initializer) {
this(initializer, ReactiveAdapterRegistry.getSharedInstance());
}
/**
* Create an instance with the given initializer and {@code ReactiveAdapterRegistry}.
* @since 6.1
*/
public BindingContext(@Nullable WebBindingInitializer initializer, ReactiveAdapterRegistry registry) {
this.initializer = initializer;
this.reactiveAdapterRegistry = new ReactiveAdapterRegistry();
}
/**
* Return the default model.
*/
public Model getModel() {
return this.model;
}
/**
* Configure flag to signal whether validation will be applied to handler
* method arguments, which is the case if Bean Validation is enabled in
* Spring MVC, and method parameters have {@code @Constraint} annotations.
* @since 6.1
*/
public void setMethodValidationApplicable(boolean methodValidationApplicable) {
this.methodValidationApplicable = methodValidationApplicable;
}
/**
* Create a binder with a target object.
* @param exchange the current exchange
* @param target the object to create a data binder for
* @param name the name of the target object
* @return the created data binder
* @throws ServerErrorException if {@code @InitBinder} method invocation fails
*/
public WebExchangeDataBinder createDataBinder(ServerWebExchange exchange, @Nullable Object target, String name) {
return createDataBinder(exchange, target, name, null);
}
/**
* Shortcut method to create a binder without a target object.
* @param exchange the current exchange
* @param name the name of the target object
* @return the created data binder
* @throws ServerErrorException if {@code @InitBinder} method invocation fails
*/
public WebExchangeDataBinder createDataBinder(ServerWebExchange exchange, String name) {
return createDataBinder(exchange, null, name, null);
}
/**
* Create a binder with a target object and a {@link ResolvableType targetType}.
* If the target is {@code null}, then
* {@link WebExchangeDataBinder#setTargetType targetType} is set.
* @since 6.1
*/
public WebExchangeDataBinder createDataBinder(
ServerWebExchange exchange, @Nullable Object target, String name, @Nullable ResolvableType targetType) {
WebExchangeDataBinder dataBinder = new ExtendedWebExchangeDataBinder(target, name);
dataBinder.setNameResolver(new BindParamNameResolver());
if (target == null && targetType != null) {
dataBinder.setTargetType(targetType);
}
if (this.initializer != null) {
this.initializer.initBinder(dataBinder);
}
dataBinder = initDataBinder(dataBinder, exchange);
if (this.methodValidationApplicable && targetType != null) {
if (targetType.getSource() instanceof MethodParameter parameter) {
MethodValidationInitializer.initBinder(dataBinder, parameter);
}
}
return dataBinder;
}
/**
* Initialize the data binder instance for the given exchange.
* @throws ServerErrorException if {@code @InitBinder} method invocation fails
*/
protected WebExchangeDataBinder initDataBinder(WebExchangeDataBinder binder, ServerWebExchange exchange) {
return binder;
}
/**
* Invoked before rendering to add {@link BindingResult} attributes where
* necessary, and also to promote model attributes listed as
* {@code @SessionAttributes} to the session.
* @param exchange the current exchange
* @since 6.1
*/
public void updateModel(ServerWebExchange exchange) {
Map model = getModel().asMap();
for (Map.Entry entry : model.entrySet()) {
String name = entry.getKey();
Object value = entry.getValue();
if (isBindingCandidate(name, value)) {
if (!model.containsKey(BindingResult.MODEL_KEY_PREFIX + name)) {
WebExchangeDataBinder binder = createDataBinder(exchange, value, name);
model.put(BindingResult.MODEL_KEY_PREFIX + name, binder.getBindingResult());
}
}
}
}
private boolean isBindingCandidate(String name, @Nullable Object value) {
return (!name.startsWith(BindingResult.MODEL_KEY_PREFIX) && value != null &&
!value.getClass().isArray() && !(value instanceof Collection) && !(value instanceof Map) &&
this.reactiveAdapterRegistry.getAdapter(null, value) == null &&
!BeanUtils.isSimpleValueType(value.getClass()));
}
/**
* Extended variant of {@link WebExchangeDataBinder}, adding path variables.
*/
private static class ExtendedWebExchangeDataBinder extends WebExchangeDataBinder {
public ExtendedWebExchangeDataBinder(@Nullable Object target, String objectName) {
super(target, objectName);
}
@Override
public Mono> getValuesToBind(ServerWebExchange exchange) {
return super.getValuesToBind(exchange).doOnNext(map ->
map.putAll(exchange.>getAttributeOrDefault(
HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, Collections.emptyMap())));
}
}
/**
* Excludes Bean Validation if the method parameter has {@code @Valid}.
*/
private static class MethodValidationInitializer {
public static void initBinder(DataBinder binder, MethodParameter parameter) {
if (ReactiveAdapterRegistry.getSharedInstance().getAdapter(parameter.getParameterType()) == null) {
for (Annotation annotation : parameter.getParameterAnnotations()) {
if (annotation.annotationType().getName().equals("jakarta.validation.Valid")) {
binder.setExcludedValidators(v -> v instanceof jakarta.validation.Validator ||
v instanceof SmartValidator sv && sv.unwrap(jakarta.validation.Validator.class) != null);
}
}
}
}
}
}