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 * <pre class="code">
045 * public class AppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
046 *       // ...
047 *       &#064;Override
048 *       protected void customizeRegistration(ServletRegistration.Dynamic registration) {
049 *     // Optionally also set maxFileSize, maxRequestSize, fileSizeThreshold
050 *     registration.setMultipartConfig(new MultipartConfigElement("/tmp"));
051 *   }
052 * }
053 * </pre>
054 *
055 * @author Juergen Hoeller
056 * @since 3.1
057 * @see #setResolveLazily
058 * @see HttpServletRequest#getParts()
059 * @see org.springframework.web.multipart.commons.CommonsMultipartResolver
060 */
061public class StandardServletMultipartResolver implements MultipartResolver {
062
063        private boolean resolveLazily = false;
064
065
066        /**
067         * Set whether to resolve the multipart request lazily at the time of
068         * file or parameter access.
069         * <p>Default is "false", resolving the multipart elements immediately, throwing
070         * corresponding exceptions at the time of the {@link #resolveMultipart} call.
071         * Switch this to "true" for lazy multipart parsing, throwing parse exceptions
072         * once the application attempts to obtain multipart files or parameters.
073         * @since 3.2.9
074         */
075        public void setResolveLazily(boolean resolveLazily) {
076                this.resolveLazily = resolveLazily;
077        }
078
079
080        @Override
081        public boolean isMultipart(HttpServletRequest request) {
082                return StringUtils.startsWithIgnoreCase(request.getContentType(), "multipart/");
083        }
084
085        @Override
086        public MultipartHttpServletRequest resolveMultipart(HttpServletRequest request) throws MultipartException {
087                return new StandardMultipartHttpServletRequest(request, this.resolveLazily);
088        }
089
090        @Override
091        public void cleanupMultipart(MultipartHttpServletRequest request) {
092                if (!(request instanceof AbstractMultipartHttpServletRequest) ||
093                                ((AbstractMultipartHttpServletRequest) request).isResolved()) {
094                        // To be on the safe side: explicitly delete the parts,
095                        // but only actual file parts (for Resin compatibility)
096                        try {
097                                for (Part part : request.getParts()) {
098                                        if (request.getFile(part.getName()) != null) {
099                                                part.delete();
100                                        }
101                                }
102                        }
103                        catch (Throwable ex) {
104                                LogFactory.getLog(getClass()).warn("Failed to perform cleanup of multipart items", ex);
105                        }
106                }
107        }
108
109}