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The Commons FileUpload DiskFileItem.java source code
/*
* 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 java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
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.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.UnsupportedEncodingException;
import java.util.Map;
import org.apache.commons.io.FileCleaningTracker;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.FileCleaner;
import org.apache.commons.io.output.DeferredFileOutputStream;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemHeaders;
import org.apache.commons.fileupload.FileItemHeadersSupport;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.ParameterParser;
/**
* <p> The default implementation of the
* {@link org.apache.commons.fileupload.FileItem FileItem} interface.
*
* <p> After retrieving an instance of this class from a {@link
* org.apache.commons.fileupload.DiskFileUpload DiskFileUpload} instance (see
* {@link org.apache.commons.fileupload.DiskFileUpload
* #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.
*
* <p>When using the DiskFileItemFactory, then you should
* 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
* automatically when the class {@link FileCleaner} is loaded.
* 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.</p>
*
* @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski
* @author <a href="mailto:sean@informage.net">Sean Legassick
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl
* @author <a href="mailto:jmcnally@apache.org">John McNally
* @author <a href="mailto:martinc@apache.org">Martin Cooper
* @author Sean C. Sullivan
*
* @since FileUpload 1.1
*
* @version $Id: DiskFileItem.java 545004 2007-06-07 00:05:29Z jochen $
*/
public class DiskFileItem
implements FileItem, FileItemHeadersSupport {
// ----------------------------------------------------- Manifest constants
/**
* The UID to use when serializing this instance.
*/
private static final long serialVersionUID = 2237570099615271025L;
/**
* 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 =
new java.rmi.server.UID().toString()
.replace(':', '_').replace('-', '_');
/**
* Counter used in unique identifier generation.
*/
private static int counter = 0;
/**
* The name of the form field as provided by the browser.
*/
private String fieldName;
/**
* The content type passed by the browser, or <code>null if
* not defined.
*/
private String contentType;
/**
* Whether or not this item is a simple form field.
*/
private boolean isFormField;
/**
* The original filename in the user's filesystem.
*/
private 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 int sizeThreshold;
/**
* The directory in which uploaded files will be stored, if stored on disk.
*/
private File repository;
/**
* Cached contents of the file.
*/
private byte[] cachedContent;
/**
* Output stream for this item.
*/
private transient DeferredFileOutputStream dfos;
/**
* File to allow for serialization of the content of this item.
*/
private File dfosFile;
/**
* The tracker, which is responsible for deleting the temporary file.
*/
private FileCleaningTracker fileCleaningTracker;
/**
* The file items headers.
*/
private FileItemHeaders headers;
// ----------------------------------------------------------- Constructors
/**
* Constructs a new <code>DiskFileItem instance.
*
* @param fieldName The name of the form field.
* @param contentType The content type passed by the browser or
* <code>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
* <code>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.
* @deprecated Use {@link #DiskFileItem(FileCleaningTracker, String, String,
* boolean, String, int, File)}.
*/
public DiskFileItem(String fieldName, String contentType,
boolean isFormField, String fileName, int sizeThreshold,
File repository) {
this(FileCleaner.getInstance(), fieldName, contentType,
isFormField, fileName, sizeThreshold,
repository);
}
/**
* Constructs a new <code>DiskFileItem instance.
*
* @param tracker The tracker, which is responsible for deleting
* the temporary file. May be null, if the file
* doesn't need to be tracked.
* @param fieldName The name of the form field.
* @param contentType The content type passed by the browser or
* <code>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
* <code>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.
*/
private DiskFileItem(FileCleaningTracker tracker, String fieldName,
String contentType, boolean isFormField, String fileName,
int sizeThreshold, File repository) {
this.fileCleaningTracker = tracker;
this.fieldName = fieldName;
this.contentType = contentType;
this.isFormField = isFormField;
this.fileName = fileName;
this.sizeThreshold = sizeThreshold;
this.repository = repository;
}
/**
* Constructs a new <code>DiskFileItem instance.
*
* @param factory The factory, which is creating this instance.
* @param fieldName The name of the form field.
* @param contentType The content type passed by the browser or
* <code>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
* <code>null if not specified.
*/
public DiskFileItem(DiskFileItemFactory factory, String fieldName,
String contentType, boolean isFormField, String fileName) {
this(factory.getFileCleaningTracker(), fieldName, contentType,
isFormField, fileName, factory.getSizeThreshold(),
factory.getRepository());
}
// ------------------------------- 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.
*/
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 <code>null if
* not defined.
*
* @return The content type passed by the agent or <code>null if
* not defined.
*/
public String getContentType() {
return contentType;
}
/**
* Returns the content charset passed by the agent or <code>null if
* not defined.
*
* @return The content charset passed by the agent or <code>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 (String) params.get("charset");
}
/**
* Returns the original filename in the client's filesystem.
*
* @return The original filename in the client's filesystem.
*/
public String getName() {
return fileName;
}
// ------------------------------------------------------- FileItem methods
/**
* Provides a hint as to whether or not the file contents will be read
* from memory.
*
* @return <code>true if the file contents will be read
* from memory; <code>false otherwise.
*/
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.
*/
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.
*/
public byte[] get() {
if (isInMemory()) {
if (cachedContent == null) {
cachedContent = dfos.getData();
}
return cachedContent;
}
byte[] fileData = new byte[(int) getSize()];
FileInputStream fis = null;
try {
fis = new FileInputStream(dfos.getFile());
fis.read(fileData);
} catch (IOException e) {
fileData = null;
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
// ignore
}
}
}
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.
*/
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.
*
* @return The contents of the file, as a string.
*
* @todo Consider making this method throw UnsupportedEncodingException.
*/
public String getString() {
byte[] rawdata = get();
String charset = getCharSet();
if (charset == null) {
charset = DEFAULT_CHARSET;
}
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.
* <p>
* 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.
* <p>
* This method is only guaranteed to work <em>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 <code>File into which the uploaded item should
* be stored.
*
* @throws Exception if an error occurs.
*/
public void write(File file) throws Exception {
if (isInMemory()) {
FileOutputStream fout = null;
try {
fout = new FileOutputStream(file);
fout.write(get());
} finally {
if (fout != null) {
fout.close();
}
}
} 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.
*/
if (!outputFile.renameTo(file)) {
BufferedInputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(
new FileInputStream(outputFile));
out = new BufferedOutputStream(
new FileOutputStream(file));
IOUtils.copy(in, out);
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
// ignore
}
}
if (out != null) {
try {
out.close();
} catch (IOException e) {
// ignore
}
}
}
}
} 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 <code>FileItem instance is garbage
* collected, this method can be used to ensure that this is done at an
* earlier time, thus preserving system resources.
*/
public void delete() {
cachedContent = null;
File outputFile = getStoreLocation();
if (outputFile != null && 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)
*
*/
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()
*
*/
public void setFieldName(String fieldName) {
this.fieldName = fieldName;
}
/**
* Determines whether or not a <code>FileItem instance represents
* a simple form field.
*
* @return <code>true if the instance represents a simple form
* field; <code>false if it represents an uploaded file.
*
* @see #setFormField(boolean)
*
*/
public boolean isFormField() {
return isFormField;
}
/**
* Specifies whether or not a <code>FileItem instance represents
* a simple form field.
*
* @param state <code>true if the instance represents a simple form
* field; <code>false if it represents an uploaded file.
*
* @see #isFormField()
*
*/
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 contensts of the file.
*
* @throws IOException if an error occurs.
*/
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 <code>FileItem's
* data's temporary location on the disk. Note that for
* <code>FileItems that have their data stored in memory,
* this method will return <code>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 <code>null if the data is stored in
* memory.
*/
public File getStoreLocation() {
return dfos == null ? null : dfos.getFile();
}
// ------------------------------------------------------ Protected methods
/**
* Removes the file contents from the temporary storage.
*/
protected void finalize() {
File outputFile = dfos.getFile();
if (outputFile != null && outputFile.exists()) {
outputFile.delete();
}
}
/**
* <p>Creates and returns a {@link java.io.File File} representing a uniquely
* named temporary file in the configured repository path.</p>
* <p>If the file item factory has an associated {@link FileCleaningTracker},
* then the lifetime of the file is tied to the lifetime of the <code>FileItem
* instance: The file will be deleted when the instance is garbage collected.</p>
*
* @return The {@link java.io.File File} to be used for temporary storage.
*/
protected File getTempFile() {
File tempDir = repository;
if (tempDir == null) {
tempDir = new File(System.getProperty("java.io.tmpdir"));
}
String tempFileName = "upload_" + UID + "_" + getUniqueId() + ".tmp";
File f = new File(tempDir, tempFileName);
if (fileCleaningTracker != null) {
/* If a tracker is present, use it. Otherwise, we've got to trust
* in the {@link #finalize()} method.
*/
fileCleaningTracker.track(f, this);
}
return f;
}
// -------------------------------------------------------- Private methods
/**
* Returns an identifier that is unique within the class loader used to
* load this class, but does not have random-like apearance.
*
* @return A String with the non-random looking instance identifier.
*/
private static String getUniqueId() {
final int limit = 100000000;
int current;
synchronized (DiskFileItem.class) {
current = counter++;
}
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.
*/
public String toString() {
return "name=" + this.getName()
+ ", StoreLocation="
+ String.valueOf(this.getStoreLocation())
+ ", size="
+ this.getSize()
+ "bytes, "
+ "isFormField=" + isFormField()
+ ", FieldName="
+ this.getFieldName();
}
// -------------------------------------------------- Serialization methods
/**
* Writes the state of this object during serialization.
*
* @param out The stream to which the state should be written.
*
* @throws IOException if an error occurs.
*/
private void writeObject(ObjectOutputStream out) throws IOException {
// Read the data
if (dfos.isInMemory()) {
cachedContent = get();
} else {
cachedContent = null;
dfosFile = dfos.getFile();
}
// write out values
out.defaultWriteObject();
}
/**
* Reads the state of this object during deserialization.
*
* @param in The stream from which the state should be read.
*
* @throws IOException if an error occurs.
* @throws ClassNotFoundException if class cannot be found.
*/
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException {
// read values
in.defaultReadObject();
OutputStream output = getOutputStream();
if (cachedContent != null) {
output.write(cachedContent);
} else {
FileInputStream input = new FileInputStream(dfosFile);
IOUtils.copy(input, output);
dfosFile.delete();
dfosFile = null;
}
output.close();
cachedContent = null;
}
/**
* Returns the file item headers.
* @return The file items headers.
*/
public FileItemHeaders getHeaders() {
return headers;
}
/**
* Sets the file item headers.
* @param pHeaders The file items headers.
*/
public void setHeaders(FileItemHeaders pHeaders) {
headers = pHeaders;
}
}
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