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; 018 019import java.io.File; 020import java.io.IOException; 021import java.io.InputStream; 022import java.nio.file.Files; 023import java.nio.file.Path; 024 025import org.springframework.core.io.InputStreamSource; 026import org.springframework.core.io.Resource; 027import org.springframework.lang.Nullable; 028import org.springframework.util.FileCopyUtils; 029 030/** 031 * A representation of an uploaded file received in a multipart request. 032 * 033 * <p>The file contents are either stored in memory or temporarily on disk. 034 * In either case, the user is responsible for copying file contents to a 035 * session-level or persistent store as and if desired. The temporary storage 036 * will be cleared at the end of request processing. 037 * 038 * @author Juergen Hoeller 039 * @author Trevor D. Cook 040 * @since 29.09.2003 041 * @see org.springframework.web.multipart.MultipartHttpServletRequest 042 * @see org.springframework.web.multipart.MultipartResolver 043 */ 044public interface MultipartFile extends InputStreamSource { 045 046 /** 047 * Return the name of the parameter in the multipart form. 048 * @return the name of the parameter (never {@code null} or empty) 049 */ 050 String getName(); 051 052 /** 053 * Return the original filename in the client's filesystem. 054 * <p>This may contain path information depending on the browser used, 055 * but it typically will not with any other than Opera. 056 * @return the original filename, or the empty String if no file has been chosen 057 * in the multipart form, or {@code null} if not defined or not available 058 * @see org.apache.commons.fileupload.FileItem#getName() 059 * @see org.springframework.web.multipart.commons.CommonsMultipartFile#setPreserveFilename 060 */ 061 @Nullable 062 String getOriginalFilename(); 063 064 /** 065 * Return the content type of the file. 066 * @return the content type, or {@code null} if not defined 067 * (or no file has been chosen in the multipart form) 068 */ 069 @Nullable 070 String getContentType(); 071 072 /** 073 * Return whether the uploaded file is empty, that is, either no file has 074 * been chosen in the multipart form or the chosen file has no content. 075 */ 076 boolean isEmpty(); 077 078 /** 079 * Return the size of the file in bytes. 080 * @return the size of the file, or 0 if empty 081 */ 082 long getSize(); 083 084 /** 085 * Return the contents of the file as an array of bytes. 086 * @return the contents of the file as bytes, or an empty byte array if empty 087 * @throws IOException in case of access errors (if the temporary store fails) 088 */ 089 byte[] getBytes() throws IOException; 090 091 /** 092 * Return an InputStream to read the contents of the file from. 093 * <p>The user is responsible for closing the returned stream. 094 * @return the contents of the file as stream, or an empty stream if empty 095 * @throws IOException in case of access errors (if the temporary store fails) 096 */ 097 @Override 098 InputStream getInputStream() throws IOException; 099 100 /** 101 * Return a Resource representation of this MultipartFile. This can be used 102 * as input to the {@code RestTemplate} or the {@code WebClient} to expose 103 * content length and the filename along with the InputStream. 104 * @return this MultipartFile adapted to the Resource contract 105 * @since 5.1 106 */ 107 default Resource getResource() { 108 return new MultipartFileResource(this); 109 } 110 111 /** 112 * Transfer the received file to the given destination file. 113 * <p>This may either move the file in the filesystem, copy the file in the 114 * filesystem, or save memory-held contents to the destination file. If the 115 * destination file already exists, it will be deleted first. 116 * <p>If the target file has been moved in the filesystem, this operation 117 * cannot be invoked again afterwards. Therefore, call this method just once 118 * in order to work with any storage mechanism. 119 * <p><b>NOTE:</b> Depending on the underlying provider, temporary storage 120 * may be container-dependent, including the base directory for relative 121 * destinations specified here (e.g. with Servlet 3.0 multipart handling). 122 * For absolute destinations, the target file may get renamed/moved from its 123 * temporary location or newly copied, even if a temporary copy already exists. 124 * @param dest the destination file (typically absolute) 125 * @throws IOException in case of reading or writing errors 126 * @throws IllegalStateException if the file has already been moved 127 * in the filesystem and is not available anymore for another transfer 128 * @see org.apache.commons.fileupload.FileItem#write(File) 129 * @see javax.servlet.http.Part#write(String) 130 */ 131 void transferTo(File dest) throws IOException, IllegalStateException; 132 133 /** 134 * Transfer the received file to the given destination file. 135 * <p>The default implementation simply copies the file input stream. 136 * @since 5.1 137 * @see #getInputStream() 138 * @see #transferTo(File) 139 */ 140 default void transferTo(Path dest) throws IOException, IllegalStateException { 141 FileCopyUtils.copy(getInputStream(), Files.newOutputStream(dest)); 142 } 143 144}