001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.fileupload.disk;
018
019import static java.lang.String.format;
020
021import java.io.ByteArrayInputStream;
022import java.io.File;
023import java.io.FileInputStream;
024import java.io.FileOutputStream;
025import java.io.IOException;
026import java.io.InputStream;
027import java.io.OutputStream;
028import java.io.UnsupportedEncodingException;
029import java.util.Map;
030import java.util.UUID;
031import java.util.concurrent.atomic.AtomicInteger;
032
033import org.apache.commons.fileupload.FileItem;
034import org.apache.commons.fileupload.FileItemHeaders;
035import org.apache.commons.fileupload.FileUploadException;
036import org.apache.commons.fileupload.ParameterParser;
037import org.apache.commons.fileupload.util.Streams;
038import org.apache.commons.io.FileUtils;
039import org.apache.commons.io.IOUtils;
040import org.apache.commons.io.output.DeferredFileOutputStream;
041
042/**
043 * <p> The default implementation of the
044 * {@link org.apache.commons.fileupload.FileItem FileItem} interface.
045 *
046 * <p> After retrieving an instance of this class from a {@link
047 * DiskFileItemFactory} instance (see
048 * {@link org.apache.commons.fileupload.servlet.ServletFileUpload
049 * #parseRequest(javax.servlet.http.HttpServletRequest)}), you may
050 * either request all contents of file at once using {@link #get()} or
051 * request an {@link java.io.InputStream InputStream} with
052 * {@link #getInputStream()} and process the file without attempting to load
053 * it into memory, which may come handy with large files.
054 *
055 * <p>Temporary files, which are created for file items, should be
056 * deleted later on. The best way to do this is using a
057 * {@link org.apache.commons.io.FileCleaningTracker}, which you can set on the
058 * {@link DiskFileItemFactory}. However, if you do use such a tracker,
059 * then you must consider the following: Temporary files are automatically
060 * deleted as soon as they are no longer needed. (More precisely, when the
061 * corresponding instance of {@link java.io.File} is garbage collected.)
062 * This is done by the so-called reaper thread, which is started and stopped
063 * automatically by the {@link org.apache.commons.io.FileCleaningTracker} when
064 * there are files to be tracked.
065 * It might make sense to terminate that thread, for example, if
066 * your web application ends. See the section on "Resource cleanup"
067 * in the users guide of commons-fileupload.</p>
068 *
069 * @since FileUpload 1.1
070 */
071public class DiskFileItem
072    implements FileItem {
073
074    // ----------------------------------------------------- Manifest constants
075
076    /**
077     * Default content charset to be used when no explicit charset
078     * parameter is provided by the sender. Media subtypes of the
079     * "text" type are defined to have a default charset value of
080     * "ISO-8859-1" when received via HTTP.
081     */
082    public static final String DEFAULT_CHARSET = "ISO-8859-1";
083
084    // ----------------------------------------------------------- Data members
085
086    /**
087     * UID used in unique file name generation.
088     */
089    private static final String UID =
090            UUID.randomUUID().toString().replace('-', '_');
091
092    /**
093     * Counter used in unique identifier generation.
094     */
095    private static final AtomicInteger COUNTER = new AtomicInteger(0);
096
097    /**
098     * The name of the form field as provided by the browser.
099     */
100    private String fieldName;
101
102    /**
103     * The content type passed by the browser, or <code>null</code> if
104     * not defined.
105     */
106    private final String contentType;
107
108    /**
109     * Whether or not this item is a simple form field.
110     */
111    private boolean isFormField;
112
113    /**
114     * The original filename in the user's filesystem.
115     */
116    private final String fileName;
117
118    /**
119     * The size of the item, in bytes. This is used to cache the size when a
120     * file item is moved from its original location.
121     */
122    private long size = -1;
123
124
125    /**
126     * The threshold above which uploads will be stored on disk.
127     */
128    private final int sizeThreshold;
129
130    /**
131     * The directory in which uploaded files will be stored, if stored on disk.
132     */
133    private final File repository;
134
135    /**
136     * Cached contents of the file.
137     */
138    private byte[] cachedContent;
139
140    /**
141     * Output stream for this item.
142     */
143    private transient DeferredFileOutputStream dfos;
144
145    /**
146     * The temporary file to use.
147     */
148    private transient File tempFile;
149
150    /**
151     * The file items headers.
152     */
153    private FileItemHeaders headers;
154
155    // ----------------------------------------------------------- Constructors
156
157    /**
158     * Constructs a new <code>DiskFileItem</code> instance.
159     *
160     * @param fieldName     The name of the form field.
161     * @param contentType   The content type passed by the browser or
162     *                      <code>null</code> if not specified.
163     * @param isFormField   Whether or not this item is a plain form field, as
164     *                      opposed to a file upload.
165     * @param fileName      The original filename in the user's filesystem, or
166     *                      <code>null</code> if not specified.
167     * @param sizeThreshold The threshold, in bytes, below which items will be
168     *                      retained in memory and above which they will be
169     *                      stored as a file.
170     * @param repository    The data repository, which is the directory in
171     *                      which files will be created, should the item size
172     *                      exceed the threshold.
173     */
174    public DiskFileItem(String fieldName,
175            String contentType, boolean isFormField, String fileName,
176            int sizeThreshold, File repository) {
177        this.fieldName = fieldName;
178        this.contentType = contentType;
179        this.isFormField = isFormField;
180        this.fileName = fileName;
181        this.sizeThreshold = sizeThreshold;
182        this.repository = repository;
183    }
184
185    // ------------------------------- Methods from javax.activation.DataSource
186
187    /**
188     * Returns an {@link java.io.InputStream InputStream} that can be
189     * used to retrieve the contents of the file.
190     *
191     * @return An {@link java.io.InputStream InputStream} that can be
192     *         used to retrieve the contents of the file.
193     *
194     * @throws IOException if an error occurs.
195     */
196    public InputStream getInputStream()
197        throws IOException {
198        if (!isInMemory()) {
199            return new FileInputStream(dfos.getFile());
200        }
201
202        if (cachedContent == null) {
203            cachedContent = dfos.getData();
204        }
205        return new ByteArrayInputStream(cachedContent);
206    }
207
208    /**
209     * Returns the content type passed by the agent or <code>null</code> if
210     * not defined.
211     *
212     * @return The content type passed by the agent or <code>null</code> if
213     *         not defined.
214     */
215    public String getContentType() {
216        return contentType;
217    }
218
219    /**
220     * Returns the content charset passed by the agent or <code>null</code> if
221     * not defined.
222     *
223     * @return The content charset passed by the agent or <code>null</code> if
224     *         not defined.
225     */
226    public String getCharSet() {
227        ParameterParser parser = new ParameterParser();
228        parser.setLowerCaseNames(true);
229        // Parameter parser can handle null input
230        Map<String, String> params = parser.parse(getContentType(), ';');
231        return params.get("charset");
232    }
233
234    /**
235     * Returns the original filename in the client's filesystem.
236     *
237     * @return The original filename in the client's filesystem.
238     * @throws org.apache.commons.fileupload.InvalidFileNameException The file name contains a NUL character,
239     *   which might be an indicator of a security attack. If you intend to
240     *   use the file name anyways, catch the exception and use
241     *   {@link org.apache.commons.fileupload.InvalidFileNameException#getName()}.
242     */
243    public String getName() {
244        return Streams.checkFileName(fileName);
245    }
246
247    // ------------------------------------------------------- FileItem methods
248
249    /**
250     * Provides a hint as to whether or not the file contents will be read
251     * from memory.
252     *
253     * @return <code>true</code> if the file contents will be read
254     *         from memory; <code>false</code> otherwise.
255     */
256    public boolean isInMemory() {
257        if (cachedContent != null) {
258            return true;
259        }
260        return dfos.isInMemory();
261    }
262
263    /**
264     * Returns the size of the file.
265     *
266     * @return The size of the file, in bytes.
267     */
268    public long getSize() {
269        if (size >= 0) {
270            return size;
271        } else if (cachedContent != null) {
272            return cachedContent.length;
273        } else if (dfos.isInMemory()) {
274            return dfos.getData().length;
275        } else {
276            return dfos.getFile().length();
277        }
278    }
279
280    /**
281     * Returns the contents of the file as an array of bytes.  If the
282     * contents of the file were not yet cached in memory, they will be
283     * loaded from the disk storage and cached.
284     *
285     * @return The contents of the file as an array of bytes
286     * or {@code null} if the data cannot be read
287     */
288    public byte[] get() {
289        if (isInMemory()) {
290            if (cachedContent == null && dfos != null) {
291                cachedContent = dfos.getData();
292            }
293            return cachedContent;
294        }
295
296        byte[] fileData = new byte[(int) getSize()];
297        InputStream fis = null;
298
299        try {
300            fis = new FileInputStream(dfos.getFile());
301            IOUtils.readFully(fis, fileData);
302        } catch (IOException e) {
303            fileData = null;
304        } finally {
305            IOUtils.closeQuietly(fis);
306        }
307
308        return fileData;
309    }
310
311    /**
312     * Returns the contents of the file as a String, using the specified
313     * encoding.  This method uses {@link #get()} to retrieve the
314     * contents of the file.
315     *
316     * @param charset The charset to use.
317     *
318     * @return The contents of the file, as a string.
319     *
320     * @throws UnsupportedEncodingException if the requested character
321     *                                      encoding is not available.
322     */
323    public String getString(final String charset)
324        throws UnsupportedEncodingException {
325        return new String(get(), charset);
326    }
327
328    /**
329     * Returns the contents of the file as a String, using the default
330     * character encoding.  This method uses {@link #get()} to retrieve the
331     * contents of the file.
332     *
333     * <b>TODO</b> Consider making this method throw UnsupportedEncodingException.
334     *
335     * @return The contents of the file, as a string.
336     */
337    public String getString() {
338        byte[] rawdata = get();
339        String charset = getCharSet();
340        if (charset == null) {
341            charset = DEFAULT_CHARSET;
342        }
343        try {
344            return new String(rawdata, charset);
345        } catch (UnsupportedEncodingException e) {
346            return new String(rawdata);
347        }
348    }
349
350    /**
351     * A convenience method to write an uploaded item to disk. The client code
352     * is not concerned with whether or not the item is stored in memory, or on
353     * disk in a temporary location. They just want to write the uploaded item
354     * to a file.
355     * <p>
356     * This implementation first attempts to rename the uploaded item to the
357     * specified destination file, if the item was originally written to disk.
358     * Otherwise, the data will be copied to the specified file.
359     * <p>
360     * This method is only guaranteed to work <em>once</em>, the first time it
361     * is invoked for a particular item. This is because, in the event that the
362     * method renames a temporary file, that file will no longer be available
363     * to copy or rename again at a later time.
364     *
365     * @param file The <code>File</code> into which the uploaded item should
366     *             be stored.
367     *
368     * @throws Exception if an error occurs.
369     */
370    public void write(File file) throws Exception {
371        if (isInMemory()) {
372            FileOutputStream fout = null;
373            try {
374                fout = new FileOutputStream(file);
375                fout.write(get());
376                fout.close();
377            } finally {
378                IOUtils.closeQuietly(fout);
379            }
380        } else {
381            File outputFile = getStoreLocation();
382            if (outputFile != null) {
383                // Save the length of the file
384                size = outputFile.length();
385                /*
386                 * The uploaded file is being stored on disk
387                 * in a temporary location so move it to the
388                 * desired file.
389                 */
390                FileUtils.moveFile(outputFile, file);
391            } else {
392                /*
393                 * For whatever reason we cannot write the
394                 * file to disk.
395                 */
396                throw new FileUploadException(
397                    "Cannot write uploaded file to disk!");
398            }
399        }
400    }
401
402    /**
403     * Deletes the underlying storage for a file item, including deleting any
404     * associated temporary disk file. Although this storage will be deleted
405     * automatically when the <code>FileItem</code> instance is garbage
406     * collected, this method can be used to ensure that this is done at an
407     * earlier time, thus preserving system resources.
408     */
409    public void delete() {
410        cachedContent = null;
411        File outputFile = getStoreLocation();
412        if (outputFile != null && outputFile.exists()) {
413            outputFile.delete();
414        }
415    }
416
417    /**
418     * Returns the name of the field in the multipart form corresponding to
419     * this file item.
420     *
421     * @return The name of the form field.
422     *
423     * @see #setFieldName(java.lang.String)
424     *
425     */
426    public String getFieldName() {
427        return fieldName;
428    }
429
430    /**
431     * Sets the field name used to reference this file item.
432     *
433     * @param fieldName The name of the form field.
434     *
435     * @see #getFieldName()
436     *
437     */
438    public void setFieldName(String fieldName) {
439        this.fieldName = fieldName;
440    }
441
442    /**
443     * Determines whether or not a <code>FileItem</code> instance represents
444     * a simple form field.
445     *
446     * @return <code>true</code> if the instance represents a simple form
447     *         field; <code>false</code> if it represents an uploaded file.
448     *
449     * @see #setFormField(boolean)
450     *
451     */
452    public boolean isFormField() {
453        return isFormField;
454    }
455
456    /**
457     * Specifies whether or not a <code>FileItem</code> instance represents
458     * a simple form field.
459     *
460     * @param state <code>true</code> if the instance represents a simple form
461     *              field; <code>false</code> if it represents an uploaded file.
462     *
463     * @see #isFormField()
464     *
465     */
466    public void setFormField(boolean state) {
467        isFormField = state;
468    }
469
470    /**
471     * Returns an {@link java.io.OutputStream OutputStream} that can
472     * be used for storing the contents of the file.
473     *
474     * @return An {@link java.io.OutputStream OutputStream} that can be used
475     *         for storing the contents of the file.
476     *
477     * @throws IOException if an error occurs.
478     */
479    public OutputStream getOutputStream()
480        throws IOException {
481        if (dfos == null) {
482            File outputFile = getTempFile();
483            dfos = new DeferredFileOutputStream(sizeThreshold, outputFile);
484        }
485        return dfos;
486    }
487
488    // --------------------------------------------------------- Public methods
489
490    /**
491     * Returns the {@link java.io.File} object for the <code>FileItem</code>'s
492     * data's temporary location on the disk. Note that for
493     * <code>FileItem</code>s that have their data stored in memory,
494     * this method will return <code>null</code>. When handling large
495     * files, you can use {@link java.io.File#renameTo(java.io.File)} to
496     * move the file to new location without copying the data, if the
497     * source and destination locations reside within the same logical
498     * volume.
499     *
500     * @return The data file, or <code>null</code> if the data is stored in
501     *         memory.
502     */
503    public File getStoreLocation() {
504        if (dfos == null) {
505            return null;
506        }
507        if (isInMemory()) {
508            return null;
509        }
510        return dfos.getFile();
511    }
512
513    // ------------------------------------------------------ Protected methods
514
515    /**
516     * Removes the file contents from the temporary storage.
517     */
518    @Override
519    protected void finalize() {
520        if (dfos == null) {
521            return;
522        }
523        File outputFile = dfos.getFile();
524
525        if (outputFile != null && outputFile.exists()) {
526            outputFile.delete();
527        }
528    }
529
530    /**
531     * Creates and returns a {@link java.io.File File} representing a uniquely
532     * named temporary file in the configured repository path. The lifetime of
533     * the file is tied to the lifetime of the <code>FileItem</code> instance;
534     * the file will be deleted when the instance is garbage collected.
535     * <p>
536     * <b>Note: Subclasses that override this method must ensure that they return the
537     * same File each time.</b>
538     *
539     * @return The {@link java.io.File File} to be used for temporary storage.
540     */
541    protected File getTempFile() {
542        if (tempFile == null) {
543            File tempDir = repository;
544            if (tempDir == null) {
545                tempDir = new File(System.getProperty("java.io.tmpdir"));
546            }
547
548            String tempFileName = format("upload_%s_%s.tmp", UID, getUniqueId());
549
550            tempFile = new File(tempDir, tempFileName);
551        }
552        return tempFile;
553    }
554
555    // -------------------------------------------------------- Private methods
556
557    /**
558     * Returns an identifier that is unique within the class loader used to
559     * load this class, but does not have random-like appearance.
560     *
561     * @return A String with the non-random looking instance identifier.
562     */
563    private static String getUniqueId() {
564        final int limit = 100000000;
565        int current = COUNTER.getAndIncrement();
566        String id = Integer.toString(current);
567
568        // If you manage to get more than 100 million of ids, you'll
569        // start getting ids longer than 8 characters.
570        if (current < limit) {
571            id = ("00000000" + id).substring(id.length());
572        }
573        return id;
574    }
575
576    /**
577     * Returns a string representation of this object.
578     *
579     * @return a string representation of this object.
580     */
581    @Override
582    public String toString() {
583        return format("name=%s, StoreLocation=%s, size=%s bytes, isFormField=%s, FieldName=%s",
584                      getName(), getStoreLocation(), Long.valueOf(getSize()),
585                      Boolean.valueOf(isFormField()), getFieldName());
586    }
587
588    /**
589     * Returns the file item headers.
590     * @return The file items headers.
591     */
592    public FileItemHeaders getHeaders() {
593        return headers;
594    }
595
596    /**
597     * Sets the file item headers.
598     * @param pHeaders The file items headers.
599     */
600    public void setHeaders(FileItemHeaders pHeaders) {
601        headers = pHeaders;
602    }
603
604}