org.apache.commons.fileupload.disk.DiskFileItem Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.commons.fileupload.disk;
import static java.lang.String.format;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemHeaders;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.ParameterParser;
import org.apache.commons.fileupload.util.Streams;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.output.DeferredFileOutputStream;
/**
* The default implementation of the
* {@link org.apache.commons.fileupload.FileItem FileItem} interface.
*
*
After retrieving an instance of this class from a {@link
* DiskFileItemFactory} instance (see
* {@link org.apache.commons.fileupload.servlet.ServletFileUpload
* #parseRequest(javax.servlet.http.HttpServletRequest)}), you may
* either request all contents of file at once using {@link #get()} or
* request an {@link java.io.InputStream InputStream} with
* {@link #getInputStream()} and process the file without attempting to load
* it into memory, which may come handy with large files.
*
*
Temporary files, which are created for file items, should be
* deleted later on. The best way to do this is using a
* {@link org.apache.commons.io.FileCleaningTracker}, which you can set on the
* {@link DiskFileItemFactory}. However, if you do use such a tracker,
* then you must consider the following: Temporary files are automatically
* deleted as soon as they are no longer needed. (More precisely, when the
* corresponding instance of {@link java.io.File} is garbage collected.)
* This is done by the so-called reaper thread, which is started and stopped
* automatically by the {@link org.apache.commons.io.FileCleaningTracker} when
* there are files to be tracked.
* It might make sense to terminate that thread, for example, if
* your web application ends. See the section on "Resource cleanup"
* in the users guide of commons-fileupload.
*
* @since FileUpload 1.1
*/
public class DiskFileItem
implements FileItem {
// ----------------------------------------------------- Manifest constants
/**
* Default content charset to be used when no explicit charset
* parameter is provided by the sender. Media subtypes of the
* "text" type are defined to have a default charset value of
* "ISO-8859-1" when received via HTTP.
*/
public static final String DEFAULT_CHARSET = "ISO-8859-1";
// ----------------------------------------------------------- Data members
/**
* UID used in unique file name generation.
*/
private static final String UID =
UUID.randomUUID().toString().replace('-', '_');
/**
* Counter used in unique identifier generation.
*/
private static final AtomicInteger COUNTER = new AtomicInteger(0);
/**
* The name of the form field as provided by the browser.
*/
private String fieldName;
/**
* The content type passed by the browser, or null if
* not defined.
*/
private final String contentType;
/**
* Whether or not this item is a simple form field.
*/
private boolean isFormField;
/**
* The original filename in the user's filesystem.
*/
private final String fileName;
/**
* The size of the item, in bytes. This is used to cache the size when a
* file item is moved from its original location.
*/
private long size = -1;
/**
* The threshold above which uploads will be stored on disk.
*/
private final int sizeThreshold;
/**
* The directory in which uploaded files will be stored, if stored on disk.
*/
private final File repository;
/**
* Cached contents of the file.
*/
private byte[] cachedContent;
/**
* Output stream for this item.
*/
private transient DeferredFileOutputStream dfos;
/**
* The temporary file to use.
*/
private transient File tempFile;
/**
* The file items headers.
*/
private FileItemHeaders headers;
/**
* Default content charset to be used when no explicit charset
* parameter is provided by the sender.
*/
private String defaultCharset = DEFAULT_CHARSET;
// ----------------------------------------------------------- Constructors
/**
* Constructs a new DiskFileItem instance.
*
* @param fieldName The name of the form field.
* @param contentType The content type passed by the browser or
* null if not specified.
* @param isFormField Whether or not this item is a plain form field, as
* opposed to a file upload.
* @param fileName The original filename in the user's filesystem, or
* null if not specified.
* @param sizeThreshold The threshold, in bytes, below which items will be
* retained in memory and above which they will be
* stored as a file.
* @param repository The data repository, which is the directory in
* which files will be created, should the item size
* exceed the threshold.
*/
public DiskFileItem(String fieldName,
String contentType, boolean isFormField, String fileName,
int sizeThreshold, File repository) {
this.fieldName = fieldName;
this.contentType = contentType;
this.isFormField = isFormField;
this.fileName = fileName;
this.sizeThreshold = sizeThreshold;
this.repository = repository;
}
// ------------------------------- Methods from javax.activation.DataSource
/**
* Returns an {@link java.io.InputStream InputStream} that can be
* used to retrieve the contents of the file.
*
* @return An {@link java.io.InputStream InputStream} that can be
* used to retrieve the contents of the file.
*
* @throws IOException if an error occurs.
*/
@Override
public InputStream getInputStream()
throws IOException {
if (!isInMemory()) {
return new FileInputStream(dfos.getFile());
}
if (cachedContent == null) {
cachedContent = dfos.getData();
}
return new ByteArrayInputStream(cachedContent);
}
/**
* Returns the content type passed by the agent or null if
* not defined.
*
* @return The content type passed by the agent or null if
* not defined.
*/
@Override
public String getContentType() {
return contentType;
}
/**
* Returns the content charset passed by the agent or null if
* not defined.
*
* @return The content charset passed by the agent or null if
* not defined.
*/
public String getCharSet() {
ParameterParser parser = new ParameterParser();
parser.setLowerCaseNames(true);
// Parameter parser can handle null input
Map params = parser.parse(getContentType(), ';');
return params.get("charset");
}
/**
* Returns the original filename in the client's filesystem.
*
* @return The original filename in the client's filesystem.
* @throws org.apache.commons.fileupload.InvalidFileNameException The file name contains a NUL character,
* which might be an indicator of a security attack. If you intend to
* use the file name anyways, catch the exception and use
* {@link org.apache.commons.fileupload.InvalidFileNameException#getName()}.
*/
@Override
public String getName() {
return Streams.checkFileName(fileName);
}
// ------------------------------------------------------- FileItem methods
/**
* Provides a hint as to whether or not the file contents will be read
* from memory.
*
* @return true if the file contents will be read
* from memory; false otherwise.
*/
@Override
public boolean isInMemory() {
if (cachedContent != null) {
return true;
}
return dfos.isInMemory();
}
/**
* Returns the size of the file.
*
* @return The size of the file, in bytes.
*/
@Override
public long getSize() {
if (size >= 0) {
return size;
} else if (cachedContent != null) {
return cachedContent.length;
} else if (dfos.isInMemory()) {
return dfos.getData().length;
} else {
return dfos.getFile().length();
}
}
/**
* Returns the contents of the file as an array of bytes. If the
* contents of the file were not yet cached in memory, they will be
* loaded from the disk storage and cached.
*
* @return The contents of the file as an array of bytes
* or {@code null} if the data cannot be read
*/
@Override
public byte[] get() {
if (isInMemory()) {
if (cachedContent == null && dfos != null) {
cachedContent = dfos.getData();
}
return cachedContent;
}
byte[] fileData = new byte[(int) getSize()];
InputStream fis = null;
try {
fis = new FileInputStream(dfos.getFile());
IOUtils.readFully(fis, fileData);
} catch (IOException e) {
fileData = null;
} finally {
IOUtils.closeQuietly(fis);
}
return fileData;
}
/**
* Returns the contents of the file as a String, using the specified
* encoding. This method uses {@link #get()} to retrieve the
* contents of the file.
*
* @param charset The charset to use.
*
* @return The contents of the file, as a string.
*
* @throws UnsupportedEncodingException if the requested character
* encoding is not available.
*/
@Override
public String getString(final String charset)
throws UnsupportedEncodingException {
return new String(get(), charset);
}
/**
* Returns the contents of the file as a String, using the default
* character encoding. This method uses {@link #get()} to retrieve the
* contents of the file.
*
* TODO Consider making this method throw UnsupportedEncodingException.
*
* @return The contents of the file, as a string.
*/
@Override
public String getString() {
byte[] rawdata = get();
String charset = getCharSet();
if (charset == null) {
charset = defaultCharset;
}
try {
return new String(rawdata, charset);
} catch (UnsupportedEncodingException e) {
return new String(rawdata);
}
}
/**
* A convenience method to write an uploaded item to disk. The client code
* is not concerned with whether or not the item is stored in memory, or on
* disk in a temporary location. They just want to write the uploaded item
* to a file.
*
* This implementation first attempts to rename the uploaded item to the
* specified destination file, if the item was originally written to disk.
* Otherwise, the data will be copied to the specified file.
*
* This method is only guaranteed to work once, the first time it
* is invoked for a particular item. This is because, in the event that the
* method renames a temporary file, that file will no longer be available
* to copy or rename again at a later time.
*
* @param file The File into which the uploaded item should
* be stored.
*
* @throws Exception if an error occurs.
*/
@Override
public void write(File file) throws Exception {
if (isInMemory()) {
FileOutputStream fout = null;
try {
fout = new FileOutputStream(file);
fout.write(get());
fout.close();
} finally {
IOUtils.closeQuietly(fout);
}
} else {
File outputFile = getStoreLocation();
if (outputFile != null) {
// Save the length of the file
size = outputFile.length();
/*
* The uploaded file is being stored on disk
* in a temporary location so move it to the
* desired file.
*/
FileUtils.moveFile(outputFile, file);
} else {
/*
* For whatever reason we cannot write the
* file to disk.
*/
throw new FileUploadException(
"Cannot write uploaded file to disk!");
}
}
}
/**
* Deletes the underlying storage for a file item, including deleting any
* associated temporary disk file. Although this storage will be deleted
* automatically when the FileItem instance is garbage
* collected, this method can be used to ensure that this is done at an
* earlier time, thus preserving system resources.
*/
@Override
public void delete() {
cachedContent = null;
File outputFile = getStoreLocation();
if (outputFile != null && !isInMemory() && outputFile.exists()) {
outputFile.delete();
}
}
/**
* Returns the name of the field in the multipart form corresponding to
* this file item.
*
* @return The name of the form field.
*
* @see #setFieldName(java.lang.String)
*
*/
@Override
public String getFieldName() {
return fieldName;
}
/**
* Sets the field name used to reference this file item.
*
* @param fieldName The name of the form field.
*
* @see #getFieldName()
*
*/
@Override
public void setFieldName(String fieldName) {
this.fieldName = fieldName;
}
/**
* Determines whether or not a FileItem instance represents
* a simple form field.
*
* @return true if the instance represents a simple form
* field; false if it represents an uploaded file.
*
* @see #setFormField(boolean)
*
*/
@Override
public boolean isFormField() {
return isFormField;
}
/**
* Specifies whether or not a FileItem instance represents
* a simple form field.
*
* @param state true if the instance represents a simple form
* field; false if it represents an uploaded file.
*
* @see #isFormField()
*
*/
@Override
public void setFormField(boolean state) {
isFormField = state;
}
/**
* Returns an {@link java.io.OutputStream OutputStream} that can
* be used for storing the contents of the file.
*
* @return An {@link java.io.OutputStream OutputStream} that can be used
* for storing the contents of the file.
*
* @throws IOException if an error occurs.
*/
@Override
public OutputStream getOutputStream()
throws IOException {
if (dfos == null) {
File outputFile = getTempFile();
dfos = new DeferredFileOutputStream(sizeThreshold, outputFile);
}
return dfos;
}
// --------------------------------------------------------- Public methods
/**
* Returns the {@link java.io.File} object for the FileItem's
* data's temporary location on the disk. Note that for
* FileItems that have their data stored in memory,
* this method will return null. When handling large
* files, you can use {@link java.io.File#renameTo(java.io.File)} to
* move the file to new location without copying the data, if the
* source and destination locations reside within the same logical
* volume.
*
* @return The data file, or null if the data is stored in
* memory.
*/
public File getStoreLocation() {
if (dfos == null) {
return null;
}
if (isInMemory()) {
return null;
}
return dfos.getFile();
}
// ------------------------------------------------------ Protected methods
/**
* Removes the file contents from the temporary storage.
*/
@Override
protected void finalize() {
if (dfos == null || dfos.isInMemory()) {
return;
}
File outputFile = dfos.getFile();
if (outputFile != null && outputFile.exists()) {
outputFile.delete();
}
}
/**
* Creates and returns a {@link java.io.File File} representing a uniquely
* named temporary file in the configured repository path. The lifetime of
* the file is tied to the lifetime of the FileItem instance;
* the file will be deleted when the instance is garbage collected.
*
* Note: Subclasses that override this method must ensure that they return the
* same File each time.
*
* @return The {@link java.io.File File} to be used for temporary storage.
*/
protected File getTempFile() {
if (tempFile == null) {
File tempDir = repository;
if (tempDir == null) {
tempDir = new File(System.getProperty("java.io.tmpdir"));
}
String tempFileName = format("upload_%s_%s.tmp", UID, getUniqueId());
tempFile = new File(tempDir, tempFileName);
}
return tempFile;
}
// -------------------------------------------------------- Private methods
/**
* Returns an identifier that is unique within the class loader used to
* load this class, but does not have random-like appearance.
*
* @return A String with the non-random looking instance identifier.
*/
private static String getUniqueId() {
final int limit = 100000000;
int current = COUNTER.getAndIncrement();
String id = Integer.toString(current);
// If you manage to get more than 100 million of ids, you'll
// start getting ids longer than 8 characters.
if (current < limit) {
id = ("00000000" + id).substring(id.length());
}
return id;
}
/**
* Returns a string representation of this object.
*
* @return a string representation of this object.
*/
@Override
public String toString() {
return format("name=%s, StoreLocation=%s, size=%s bytes, isFormField=%s, FieldName=%s",
getName(), getStoreLocation(), Long.valueOf(getSize()),
Boolean.valueOf(isFormField()), getFieldName());
}
/**
* Returns the file item headers.
* @return The file items headers.
*/
@Override
public FileItemHeaders getHeaders() {
return headers;
}
/**
* Sets the file item headers.
* @param pHeaders The file items headers.
*/
@Override
public void setHeaders(FileItemHeaders pHeaders) {
headers = pHeaders;
}
/**
* Returns the default charset for use when no explicit charset
* parameter is provided by the sender.
* @return the default charset
*/
public String getDefaultCharset() {
return defaultCharset;
}
/**
* Sets the default charset for use when no explicit charset
* parameter is provided by the sender.
* @param charset the default charset
*/
public void setDefaultCharset(String charset) {
defaultCharset = charset;
}
}