org.springframework.web.multipart.MultipartFile Maven / Gradle / Ivy
/*
* 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.
*/
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
* @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.
* @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.
* @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.
* @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.
*/
boolean isEmpty();
/**
* 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.
* @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.
* @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 {@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.
* @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.
* @since 5.1
* @see #getInputStream()
* @see #transferTo(File)
*/
default void transferTo(Path dest) throws IOException, IllegalStateException {
FileCopyUtils.copy(getInputStream(), Files.newOutputStream(dest));
}
}