/*
 * 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
 *
 *      http://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.
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package org.springframework.web.multipart;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;

import org.springframework.core.io.InputStreamSource;
import org.springframework.core.io.Resource;
import org.springframework.lang.Nullable;
import org.springframework.util.FileCopyUtils;

A representation of an uploaded file received in a multipart request.

The file contents are either stored in memory or temporarily on disk. In either case, the user is responsible for copying file contents to a session-level or persistent store as and if desired. The temporary storage will be cleared at the end of request processing.

Author:Juergen Hoeller, Trevor D. Cook
See Also:
Since:29.09.2003
/** * A representation of an uploaded file received in a multipart request. * * <p>The file contents are either stored in memory or temporarily on disk. * In either case, the user is responsible for copying file contents to a * session-level or persistent store as and if desired. The temporary storage * will be cleared at the end of request processing. * * @author Juergen Hoeller * @author Trevor D. Cook * @since 29.09.2003 * @see org.springframework.web.multipart.MultipartHttpServletRequest * @see org.springframework.web.multipart.MultipartResolver */
public interface MultipartFile extends InputStreamSource {
Return the name of the parameter in the multipart form.
Returns:the name of the parameter (never null or empty)
/** * Return the name of the parameter in the multipart form. * @return the name of the parameter (never {@code null} or empty) */
String getName();
Return the original filename in the client's filesystem.

This may contain path information depending on the browser used, but it typically will not with any other than Opera.

See Also:
Returns:the original filename, or the empty String if no file has been chosen in the multipart form, or null if not defined or not available
/** * Return the original filename in the client's filesystem. * <p>This may contain path information depending on the browser used, * but it typically will not with any other than Opera. * @return the original filename, or the empty String if no file has been chosen * in the multipart form, or {@code null} if not defined or not available * @see org.apache.commons.fileupload.FileItem#getName() * @see org.springframework.web.multipart.commons.CommonsMultipartFile#setPreserveFilename */
@Nullable String getOriginalFilename();
Return the content type of the file.
Returns:the content type, or null if not defined (or no file has been chosen in the multipart form)
/** * Return the content type of the file. * @return the content type, or {@code null} if not defined * (or no file has been chosen in the multipart form) */
@Nullable String getContentType();
Return whether the uploaded file is empty, that is, either no file has been chosen in the multipart form or the chosen file has no content.
/** * Return whether the uploaded file is empty, that is, either no file has * been chosen in the multipart form or the chosen file has no content. */
boolean isEmpty();
Return the size of the file in bytes.
Returns:the size of the file, or 0 if empty
/** * Return the size of the file in bytes. * @return the size of the file, or 0 if empty */
long getSize();
Return the contents of the file as an array of bytes.
Throws:
  • IOException – in case of access errors (if the temporary store fails)
Returns:the contents of the file as bytes, or an empty byte array if empty
/** * Return the contents of the file as an array of bytes. * @return the contents of the file as bytes, or an empty byte array if empty * @throws IOException in case of access errors (if the temporary store fails) */
byte[] getBytes() throws IOException;
Return an InputStream to read the contents of the file from.

The user is responsible for closing the returned stream.

Throws:
  • IOException – in case of access errors (if the temporary store fails)
Returns:the contents of the file as stream, or an empty stream if empty
/** * Return an InputStream to read the contents of the file from. * <p>The user is responsible for closing the returned stream. * @return the contents of the file as stream, or an empty stream if empty * @throws IOException in case of access errors (if the temporary store fails) */
@Override InputStream getInputStream() throws IOException;
Return a Resource representation of this MultipartFile. This can be used as input to the RestTemplate or the WebClient to expose content length and the filename along with the InputStream.
Returns:this MultipartFile adapted to the Resource contract
Since:5.1
/** * Return a Resource representation of this MultipartFile. This can be used * as input to the {@code RestTemplate} or the {@code WebClient} to expose * content length and the filename along with the InputStream. * @return this MultipartFile adapted to the Resource contract * @since 5.1 */
default Resource getResource() { return new MultipartFileResource(this); }
Transfer the received file to the given destination file.

This may either move the file in the filesystem, copy the file in the filesystem, or save memory-held contents to the destination file. If the destination file already exists, it will be deleted first.

If the target file has been moved in the filesystem, this operation cannot be invoked again afterwards. Therefore, call this method just once in order to work with any storage mechanism.

NOTE: Depending on the underlying provider, temporary storage may be container-dependent, including the base directory for relative destinations specified here (e.g. with Servlet 3.0 multipart handling). For absolute destinations, the target file may get renamed/moved from its temporary location or newly copied, even if a temporary copy already exists.

Params:
  • dest – the destination file (typically absolute)
Throws:
  • IOException – in case of reading or writing errors
  • IllegalStateException – if the file has already been moved in the filesystem and is not available anymore for another transfer
See Also:
/** * Transfer the received file to the given destination file. * <p>This may either move the file in the filesystem, copy the file in the * filesystem, or save memory-held contents to the destination file. If the * destination file already exists, it will be deleted first. * <p>If the target file has been moved in the filesystem, this operation * cannot be invoked again afterwards. Therefore, call this method just once * in order to work with any storage mechanism. * <p><b>NOTE:</b> Depending on the underlying provider, temporary storage * may be container-dependent, including the base directory for relative * destinations specified here (e.g. with Servlet 3.0 multipart handling). * For absolute destinations, the target file may get renamed/moved from its * temporary location or newly copied, even if a temporary copy already exists. * @param dest the destination file (typically absolute) * @throws IOException in case of reading or writing errors * @throws IllegalStateException if the file has already been moved * in the filesystem and is not available anymore for another transfer * @see org.apache.commons.fileupload.FileItem#write(File) * @see javax.servlet.http.Part#write(String) */
void transferTo(File dest) throws IOException, IllegalStateException;
Transfer the received file to the given destination file.

The default implementation simply copies the file input stream.

See Also:
Since:5.1
/** * Transfer the received file to the given destination file. * <p>The default implementation simply copies the file input stream. * @since 5.1 * @see #getInputStream() * @see #transferTo(File) */
default void transferTo(Path dest) throws IOException, IllegalStateException { FileCopyUtils.copy(getInputStream(), Files.newOutputStream(dest)); } }