001/*
002 * Copyright 2002-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.multipart.support;
018
019import javax.servlet.http.HttpServletRequest;
020import javax.servlet.http.Part;
021
022import org.apache.commons.logging.LogFactory;
023
024import org.springframework.util.StringUtils;
025import org.springframework.web.multipart.MultipartException;
026import org.springframework.web.multipart.MultipartHttpServletRequest;
027import org.springframework.web.multipart.MultipartResolver;
028
029/**
030 * Standard implementation of the {@link MultipartResolver} interface,
031 * based on the Servlet 3.0 {@link javax.servlet.http.Part} API.
032 * To be added as "multipartResolver" bean to a Spring DispatcherServlet context,
033 * without any extra configuration at the bean level (see below).
034 *
035 * <p><b>Note:</b> In order to use Servlet 3.0 based multipart parsing,
036 * you need to mark the affected servlet with a "multipart-config" section in
037 * {@code web.xml}, or with a {@link javax.servlet.MultipartConfigElement}
038 * in programmatic servlet registration, or (in case of a custom servlet class)
039 * possibly with a {@link javax.servlet.annotation.MultipartConfig} annotation
040 * on your servlet class. Configuration settings such as maximum sizes or
041 * storage locations need to be applied at that servlet registration level;
042 * Servlet 3.0 does not allow for them to be set at the MultipartResolver level.
043 *
044 * @author Juergen Hoeller
045 * @since 3.1
046 * @see #setResolveLazily
047 * @see HttpServletRequest#getParts()
048 * @see org.springframework.web.multipart.commons.CommonsMultipartResolver
049 */
050public class StandardServletMultipartResolver implements MultipartResolver {
051
052        private boolean resolveLazily = false;
053
054
055        /**
056         * Set whether to resolve the multipart request lazily at the time of
057         * file or parameter access.
058         * <p>Default is "false", resolving the multipart elements immediately, throwing
059         * corresponding exceptions at the time of the {@link #resolveMultipart} call.
060         * Switch this to "true" for lazy multipart parsing, throwing parse exceptions
061         * once the application attempts to obtain multipart files or parameters.
062         * @since 3.2.9
063         */
064        public void setResolveLazily(boolean resolveLazily) {
065                this.resolveLazily = resolveLazily;
066        }
067
068
069        @Override
070        public boolean isMultipart(HttpServletRequest request) {
071                // Same check as in Commons FileUpload...
072                if (!"post".equalsIgnoreCase(request.getMethod())) {
073                        return false;
074                }
075                String contentType = request.getContentType();
076                return StringUtils.startsWithIgnoreCase(contentType, "multipart/");
077        }
078
079        @Override
080        public MultipartHttpServletRequest resolveMultipart(HttpServletRequest request) throws MultipartException {
081                return new StandardMultipartHttpServletRequest(request, this.resolveLazily);
082        }
083
084        @Override
085        public void cleanupMultipart(MultipartHttpServletRequest request) {
086                if (!(request instanceof AbstractMultipartHttpServletRequest) ||
087                                ((AbstractMultipartHttpServletRequest) request).isResolved()) {
088                        // To be on the safe side: explicitly delete the parts,
089                        // but only actual file parts (for Resin compatibility)
090                        try {
091                                for (Part part : request.getParts()) {
092                                        if (request.getFile(part.getName()) != null) {
093                                                part.delete();
094                                        }
095                                }
096                        }
097                        catch (Throwable ex) {
098                                LogFactory.getLog(getClass()).warn("Failed to perform cleanup of multipart items", ex);
099                        }
100                }
101        }
102
103}