/*
* 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.reactive.result.method.annotation;
import java.util.Map;
import java.util.Optional;
import reactor.core.publisher.Mono;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.converter.Converter;
import org.springframework.ui.ModelMap;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ValueConstants;
import org.springframework.web.reactive.HandlerMapping;
import org.springframework.web.server.ServerErrorException;
import org.springframework.web.server.ServerWebExchange;
/**
* Resolves method arguments annotated with @{@link PathVariable}.
*
* <p>An @{@link PathVariable} is a named value that gets resolved from a URI
* template variable. It is always required and does not have a default value
* to fall back on. See the base class
* {@link org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver}
* for more information on how named values are processed.
*
* <p>If the method parameter type is {@link Map}, the name specified in the
* annotation is used to resolve the URI variable String value. The value is
* then converted to a {@link Map} via type conversion, assuming a suitable
* {@link Converter}.
*
* @author Rossen Stoyanchev
* @see PathVariableMapMethodArgumentResolver
*/
public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
public PathVariableMethodArgumentResolver(ConversionService conversionService,
ConfigurableBeanFactory beanFactory) {
super(conversionService, beanFactory);
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
if (!parameter.hasParameterAnnotation(PathVariable.class)) {
return false;
}
if (Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())) {
String paramName = parameter.getParameterAnnotation(PathVariable.class).value();
return StringUtils.hasText(paramName);
}
return true;
}
@Override
protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
PathVariable annotation = parameter.getParameterAnnotation(PathVariable.class);
return new PathVariableNamedValueInfo(annotation);
}
@Override
@SuppressWarnings("unchecked")
protected Mono<Object> resolveName(String name, MethodParameter parameter, ServerWebExchange exchange) {
String attributeName = HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE;
Optional<Object> optional = exchange.getAttribute(attributeName);
Object value = null;
if (optional.isPresent()) {
value = ((Map<String, String>) optional.get()).get(name);
}
return Mono.justOrEmpty(value);
}
@Override
protected void handleMissingValue(String name, MethodParameter parameter) {
throw new ServerErrorException(name, parameter);
}
@Override
@SuppressWarnings("unchecked")
protected void handleResolvedValue(Object arg, String name, MethodParameter parameter,
ModelMap model, ServerWebExchange exchange) {
// TODO: View.PATH_VARIABLES ?
}
private static class PathVariableNamedValueInfo extends NamedValueInfo {
public PathVariableNamedValueInfo(PathVariable annotation) {
super(annotation.value(), true, ValueConstants.DEFAULT_NONE);
}
}
}