org.springframework.web.servlet.mvc.method.annotation.MatrixVariableMapMethodArgumentResolver Maven / Gradle / Ivy
/*
* 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
*
* 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.servlet.mvc.method.annotation;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.springframework.core.MethodParameter;
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.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.servlet.HandlerMapping;
/**
* 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.
*
* 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 3.2
*/
public class MatrixVariableMapMethodArgumentResolver implements HandlerMethodArgumentResolver {
@Override
public boolean supportsParameter(MethodParameter parameter) {
MatrixVariable matrixVariable = parameter.getParameterAnnotation(MatrixVariable.class);
return (matrixVariable != null && Map.class.isAssignableFrom(parameter.getParameterType()) &&
!StringUtils.hasText(matrixVariable.name()));
}
@Override
@Nullable
public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
NativeWebRequest request, @Nullable WebDataBinderFactory binderFactory) throws Exception {
@SuppressWarnings("unchecked")
Map> matrixVariables =
(Map>) request.getAttribute(
HandlerMapping.MATRIX_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
if (CollectionUtils.isEmpty(matrixVariables)) {
return Collections.emptyMap();
}
MultiValueMap map = new LinkedMultiValueMap<>();
MatrixVariable ann = parameter.getParameterAnnotation(MatrixVariable.class);
Assert.state(ann != null, "No MatrixVariable annotation");
String pathVariable = ann.pathVar();
if (!pathVariable.equals(ValueConstants.DEFAULT_NONE)) {
MultiValueMap mapForPathVariable = matrixVariables.get(pathVariable);
if (mapForPathVariable == null) {
return Collections.emptyMap();
}
map.putAll(mapForPathVariable);
}
else {
for (MultiValueMap 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;
}
}