/* * 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. * 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.Collections; import java.util.List; import java.util.Map; import org.springframework.core.MethodParameter; import org.springframework.core.ReactiveAdapterRegistry; import org.springframework.core.ResolvableType; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.CollectionUtils; import org.springframework.util.LinkedMultiValueMap; import org.springframework.util.MultiValueMap; import org.springframework.util.StringUtils; import org.springframework.web.bind.annotation.MatrixVariable; import org.springframework.web.bind.annotation.ValueConstants; import org.springframework.web.reactive.BindingContext; import org.springframework.web.reactive.HandlerMapping; import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverSupport; import org.springframework.web.reactive.result.method.SyncHandlerMethodArgumentResolver; import org.springframework.web.server.ServerWebExchange; /** * Resolves arguments of type {@link Map} annotated with {@link MatrixVariable @MatrixVariable} * where the annotation does not specify a name. In other words the purpose of this resolver * is to provide access to multiple matrix variables, either all or associated with a specific * path variable. * * <p>When a name is specified, an argument of type Map is considered to be a single attribute * with a Map value, and is resolved by {@link MatrixVariableMethodArgumentResolver} instead. * * @author Rossen Stoyanchev * @since 5.0.1 * @see MatrixVariableMethodArgumentResolver */ public class MatrixVariableMapMethodArgumentResolver extends HandlerMethodArgumentResolverSupport implements SyncHandlerMethodArgumentResolver { public MatrixVariableMapMethodArgumentResolver(ReactiveAdapterRegistry registry) { super(registry); } @Override public boolean supportsParameter(MethodParameter parameter) { return checkAnnotatedParamNoReactiveWrapper(parameter, MatrixVariable.class, (ann, type) -> (Map.class.isAssignableFrom(type) && !StringUtils.hasText(ann.name()))); } @Nullable @Override public Object resolveArgumentValue(MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange) { Map<String, MultiValueMap<String, String>> matrixVariables = exchange.getAttribute(HandlerMapping.MATRIX_VARIABLES_ATTRIBUTE); if (CollectionUtils.isEmpty(matrixVariables)) { return Collections.emptyMap(); } MultiValueMap<String, String> map = new LinkedMultiValueMap<>(); MatrixVariable annotation = parameter.getParameterAnnotation(MatrixVariable.class); Assert.state(annotation != null, "No MatrixVariable annotation"); String pathVariable = annotation.pathVar(); if (!pathVariable.equals(ValueConstants.DEFAULT_NONE)) { MultiValueMap<String, String> mapForPathVariable = matrixVariables.get(pathVariable); if (mapForPathVariable == null) { return Collections.emptyMap(); } map.putAll(mapForPathVariable); } else { for (MultiValueMap<String, String> vars : matrixVariables.values()) { vars.forEach((name, values) -> { for (String value : values) { map.add(name, value); } }); } } return (isSingleValueMap(parameter) ? map.toSingleValueMap() : map); } private boolean isSingleValueMap(MethodParameter parameter) { if (!MultiValueMap.class.isAssignableFrom(parameter.getParameterType())) { ResolvableType[] genericTypes = ResolvableType.forMethodParameter(parameter).getGenerics(); if (genericTypes.length == 2) { return !List.class.isAssignableFrom(genericTypes[1].toClass()); } } return false; } }