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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.fileupload.disk;
18  
19  import static java.lang.String.format;
20  
21  import java.io.ByteArrayInputStream;
22  import java.io.File;
23  import java.io.FileInputStream;
24  import java.io.FileOutputStream;
25  import java.io.IOException;
26  import java.io.InputStream;
27  import java.io.OutputStream;
28  import java.io.UnsupportedEncodingException;
29  import java.util.Map;
30  import java.util.UUID;
31  import java.util.concurrent.atomic.AtomicInteger;
32  
33  import org.apache.commons.fileupload.FileItem;
34  import org.apache.commons.fileupload.FileItemHeaders;
35  import org.apache.commons.fileupload.FileUploadException;
36  import org.apache.commons.fileupload.ParameterParser;
37  import org.apache.commons.fileupload.util.Streams;
38  import org.apache.commons.io.FileUtils;
39  import org.apache.commons.io.IOUtils;
40  import org.apache.commons.io.output.DeferredFileOutputStream;
41  
42  /**
43   * <p> The default implementation of the
44   * {@link org.apache.commons.fileupload.FileItem FileItem} interface.
45   *
46   * <p> After retrieving an instance of this class from a {@link
47   * DiskFileItemFactory} instance (see
48   * {@link org.apache.commons.fileupload.servlet.ServletFileUpload
49   * #parseRequest(javax.servlet.http.HttpServletRequest)}), you may
50   * either request all contents of file at once using {@link #get()} or
51   * request an {@link java.io.InputStream InputStream} with
52   * {@link #getInputStream()} and process the file without attempting to load
53   * it into memory, which may come handy with large files.
54   *
55   * <p>Temporary files, which are created for file items, should be
56   * deleted later on. The best way to do this is using a
57   * {@link org.apache.commons.io.FileCleaningTracker}, which you can set on the
58   * {@link DiskFileItemFactory}. However, if you do use such a tracker,
59   * then you must consider the following: Temporary files are automatically
60   * deleted as soon as they are no longer needed. (More precisely, when the
61   * corresponding instance of {@link java.io.File} is garbage collected.)
62   * This is done by the so-called reaper thread, which is started and stopped
63   * automatically by the {@link org.apache.commons.io.FileCleaningTracker} when
64   * there are files to be tracked.
65   * It might make sense to terminate that thread, for example, if
66   * your web application ends. See the section on "Resource cleanup"
67   * in the users guide of commons-fileupload.</p>
68   *
69   * @since FileUpload 1.1
70   */
71  public class DiskFileItem
72      implements FileItem {
73  
74      // ----------------------------------------------------- Manifest constants
75  
76      /**
77       * Default content charset to be used when no explicit charset
78       * parameter is provided by the sender. Media subtypes of the
79       * "text" type are defined to have a default charset value of
80       * "ISO-8859-1" when received via HTTP.
81       */
82      public static final String DEFAULT_CHARSET = "ISO-8859-1";
83  
84      // ----------------------------------------------------------- Data members
85  
86      /**
87       * UID used in unique file name generation.
88       */
89      private static final String UID =
90              UUID.randomUUID().toString().replace('-', '_');
91  
92      /**
93       * Counter used in unique identifier generation.
94       */
95      private static final AtomicInteger COUNTER = new AtomicInteger(0);
96  
97      /**
98       * The name of the form field as provided by the browser.
99       */
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 }