org.springframework.web.multipart.support.MultipartResolutionDelegate Maven / Gradle / Ivy
/*
* Copyright 2002-2019 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.multipart.support;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.Part;
import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.lang.Nullable;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.MultipartRequest;
import org.springframework.web.util.WebUtils;
/**
* A common delegate for {@code HandlerMethodArgumentResolver} implementations
* which need to resolve {@link MultipartFile} and {@link Part} arguments.
*
* @author Juergen Hoeller
* @since 4.3
*/
public final class MultipartResolutionDelegate {
/**
* Indicates an unresolvable value.
*/
public static final Object UNRESOLVABLE = new Object();
private MultipartResolutionDelegate() {
}
@Nullable
public static MultipartRequest resolveMultipartRequest(NativeWebRequest webRequest) {
MultipartRequest multipartRequest = webRequest.getNativeRequest(MultipartRequest.class);
if (multipartRequest != null) {
return multipartRequest;
}
HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
if (servletRequest != null && isMultipartContent(servletRequest)) {
return new StandardMultipartHttpServletRequest(servletRequest);
}
return null;
}
public static boolean isMultipartRequest(HttpServletRequest request) {
return (WebUtils.getNativeRequest(request, MultipartHttpServletRequest.class) != null ||
isMultipartContent(request));
}
private static boolean isMultipartContent(HttpServletRequest request) {
String contentType = request.getContentType();
return (contentType != null && contentType.toLowerCase().startsWith("multipart/"));
}
static MultipartHttpServletRequest asMultipartHttpServletRequest(HttpServletRequest request) {
MultipartHttpServletRequest unwrapped = WebUtils.getNativeRequest(request, MultipartHttpServletRequest.class);
if (unwrapped != null) {
return unwrapped;
}
return new StandardMultipartHttpServletRequest(request);
}
public static boolean isMultipartArgument(MethodParameter parameter) {
Class paramType = parameter.getNestedParameterType();
return (MultipartFile.class == paramType ||
isMultipartFileCollection(parameter) || isMultipartFileArray(parameter) ||
(Part.class == paramType || isPartCollection(parameter) || isPartArray(parameter)));
}
@Nullable
public static Object resolveMultipartArgument(String name, MethodParameter parameter, HttpServletRequest request)
throws Exception {
MultipartHttpServletRequest multipartRequest =
WebUtils.getNativeRequest(request, MultipartHttpServletRequest.class);
boolean isMultipart = (multipartRequest != null || isMultipartContent(request));
if (MultipartFile.class == parameter.getNestedParameterType()) {
if (multipartRequest == null && isMultipart) {
multipartRequest = new StandardMultipartHttpServletRequest(request);
}
return (multipartRequest != null ? multipartRequest.getFile(name) : null);
}
else if (isMultipartFileCollection(parameter)) {
if (multipartRequest == null && isMultipart) {
multipartRequest = new StandardMultipartHttpServletRequest(request);
}
return (multipartRequest != null ? multipartRequest.getFiles(name) : null);
}
else if (isMultipartFileArray(parameter)) {
if (multipartRequest == null && isMultipart) {
multipartRequest = new StandardMultipartHttpServletRequest(request);
}
if (multipartRequest != null) {
List multipartFiles = multipartRequest.getFiles(name);
return multipartFiles.toArray(new MultipartFile[0]);
}
else {
return null;
}
}
else if (Part.class == parameter.getNestedParameterType()) {
return (isMultipart ? request.getPart(name): null);
}
else if (isPartCollection(parameter)) {
return (isMultipart ? resolvePartList(request, name) : null);
}
else if (isPartArray(parameter)) {
return (isMultipart ? resolvePartList(request, name).toArray(new Part[0]) : null);
}
else {
return UNRESOLVABLE;
}
}
private static boolean isMultipartFileCollection(MethodParameter methodParam) {
return (MultipartFile.class == getCollectionParameterType(methodParam));
}
private static boolean isMultipartFileArray(MethodParameter methodParam) {
return (MultipartFile.class == methodParam.getNestedParameterType().getComponentType());
}
private static boolean isPartCollection(MethodParameter methodParam) {
return (Part.class == getCollectionParameterType(methodParam));
}
private static boolean isPartArray(MethodParameter methodParam) {
return (Part.class == methodParam.getNestedParameterType().getComponentType());
}
@Nullable
private static Class getCollectionParameterType(MethodParameter methodParam) {
Class paramType = methodParam.getNestedParameterType();
if (Collection.class == paramType || List.class.isAssignableFrom(paramType)){
Class valueType = ResolvableType.forMethodParameter(methodParam).asCollection().resolveGeneric();
if (valueType != null) {
return valueType;
}
}
return null;
}
private static List resolvePartList(HttpServletRequest request, String name) throws Exception {
Collection parts = request.getParts();
List result = new ArrayList<>(parts.size());
for (Part part : parts) {
if (part.getName().equals(name)) {
result.add(part);
}
}
return result;
}
}