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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 java.io.ByteArrayInputStream;
    20  import java.io.File;
    21  import java.io.FileOutputStream;
    22  import java.io.IOException;
    23  import java.io.InputStream;
    24  import java.io.OutputStream;
    25  import java.io.UncheckedIOException;
    26  import java.io.UnsupportedEncodingException;
    27  import java.nio.file.Files;
    28  import java.util.Map;
    29  import java.util.UUID;
    30  import java.util.concurrent.atomic.AtomicInteger;
    31
    32  import org.apache.commons.fileupload.FileItem;
    33  import org.apache.commons.fileupload.FileItemHeaders;
    34  import org.apache.commons.fileupload.FileUploadException;
    35  import org.apache.commons.fileupload.ParameterParser;
    36  import org.apache.commons.fileupload.util.Streams;
    37  import org.apache.commons.io.FileUtils;
    38  import org.apache.commons.io.function.Uncheck;
    39  import org.apache.commons.io.output.DeferredFileOutputStream;
    40
    41  /**
    42   * The default implementation of the {@link org.apache.commons.fileupload.FileItem FileItem} interface.
    43   *
    44   * <p>
    45   * After retrieving an instance of this class from a {@link DiskFileItemFactory} instance (see {@link org.apache.commons.fileupload.servlet.ServletFileUpload
    46   * #parseRequest(javax.servlet.http.HttpServletRequest)}), you may either request all contents of file at once using {@link #get()} or request an
    47   * {@link java.io.InputStream InputStream} with {@link #getInputStream()} and process the file without attempting to load it into memory, which may come handy
    48   * with large files.
    49   * </p>
    50   * <p>
    51   * Temporary files, which are created for file items, should be deleted later on. The best way to do this is using a
    52   * {@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
    53   * consider the following: Temporary files are automatically deleted as soon as they are no longer needed. (More precisely, when the corresponding instance of
    54   * {@link java.io.File} is garbage collected.) This is done by the so-called reaper thread, which is started and stopped automatically by the
    55   * {@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
    56   * application ends. See the section on "Resource cleanup" in the users guide of commons-fileupload.
    57   * </p>
    58   *
    59   * @since FileUpload 1.1
    60   */
    61  public class DiskFileItem implements FileItem {
    62
    63      /**
    64       * Counter used in unique identifier generation.
    65       */
    66      private static final AtomicInteger COUNTER = new AtomicInteger(0);
    67
    68      /**
    69       * Default content charset to be used when no explicit charset
    70       * parameter is provided by the sender. Media subtypes of the
    71       * "text" type are defined to have a default charset value of
    72       * "ISO-8859-1" when received via HTTP.
    73       */
    74      public static final String DEFAULT_CHARSET = "ISO-8859-1";
    75
    76      /**
    77       * UID used in unique file name generation.
    78       */
    79      private static final String UID = UUID.randomUUID().toString().replace('-', '_');
    80
    81      /**
    82       * Returns an identifier that is unique within the class loader used to
    83       * load this class, but does not have random-like appearance.
    84       *
    85       * @return A String with the non-random looking instance identifier.
    86       */
    87      private static String getUniqueId() {
    88          final int limit = 100000000;
    89          final int current = COUNTER.getAndIncrement();
    90          String id = Integer.toString(current);
    91
    92          // If you manage to get more than 100 million of ids, you'll
    93          // start getting ids longer than 8 characters.
    94          if (current < limit) {
    95              id = ("00000000" + id).substring(id.length());
    96          }
    97          return id;
    98      }
    99
    100     /**
    101      * Cached contents of the file.
    102      */
    103     private byte[] cachedContent;
    104
    105     /**
    106      * The content type passed by the browser, or {@code null} if not defined.
    107      */
    108     private final String contentType;
    109
    110     /**
    111      * Default content charset to be used when no explicit charset parameter is provided by the sender.
    112      */
    113     private String defaultCharset = DEFAULT_CHARSET;
    114
    115     /**
    116      * Output stream for this item.
    117      */
    118     private transient DeferredFileOutputStream dfos;
    119
    120     /**
    121      * The name of the form field as provided by the browser.
    122      */
    123     private String fieldName;
    124
    125     /**
    126      * The original file name in the user's file system.
    127      */
    128     private final String fileName;
    129
    130     /**
    131      * The file items headers.
    132      */
    133     private FileItemHeaders headers;
    134
    135     /**
    136      * Whether or not this item is a simple form field.
    137      */
    138     private boolean formField;
    139
    140     /**
    141      * The directory in which uploaded files will be stored, if stored on disk.
    142      */
    143     private final File repository;
    144
    145     /**
    146      * The size of the item, in bytes. This is used to cache the size when a
    147      * file item is moved from its original location.
    148      */
    149     private long size = -1;
    150
    151     /**
    152      * The threshold above which uploads will be stored on disk.
    153      */
    154     private final int sizeThreshold;
    155
    156     /**
    157      * The temporary file to use.
    158      */
    159     private transient File tempFile;
    160
    161     /**
    162      * Constructs a new {@code DiskFileItem} instance.
    163      *
    164      * @param fieldName     The name of the form field.
    165      * @param contentType   The content type passed by the browser or {@code null} if not specified.
    166      * @param isFormField   Whether or not this item is a plain form field, as opposed to a file upload.
    167      * @param fileName      The original file name in the user's file system, or {@code null} if not specified.
    168      * @param sizeThreshold The threshold, in bytes, below which items will be retained in memory and above which they
    169      *                      will be stored as a file.
    170      * @param repository    The data repository, which is the directory in which files will be created, should the item
    171      *                      size exceed the threshold.
    172      */
    173     public DiskFileItem(final String fieldName, final String contentType, final boolean isFormField,
    174             final String fileName, final int sizeThreshold, final File repository) {
    175         this.fieldName = fieldName;
    176         this.contentType = contentType;
    177         this.formField = isFormField;
    178         this.fileName = fileName;
    179         this.sizeThreshold = sizeThreshold;
    180         this.repository = repository;
    181     }
    182
    183     /**
    184      * Clears the cache.
    185      */
    186     private void clear() {
    187         cachedContent = null; // NOPMD
    188     }
    189
    190     /**
    191      * Deletes the underlying storage for a file item, including deleting any
    192      * associated temporary disk file. Although this storage will be deleted
    193      * automatically when the {@code FileItem} instance is garbage
    194      * collected, this method can be used to ensure that this is done at an
    195      * earlier time, thus preserving system resources.
    196      */
    197     @Override
    198     public void delete() {
    199         clear();
    200         final File outputFile = getStoreLocation();
    201         if (outputFile != null && !isInMemory() && outputFile.exists()) {
    202             outputFile.delete();
    203         }
    204     }
    205
    206     /**
    207      * Removes the file contents from the temporary storage.
    208      *
    209      * @throws Throwable Thrown by {@link Object#finalize()}.
    210      */
    211     @Override
    212     protected void finalize() throws Throwable {
    213         if (dfos == null || dfos.isInMemory()) {
    214             return;
    215         }
    216         final File outputFile = dfos.getFile();
    217         if (outputFile != null && outputFile.exists()) {
    218             outputFile.delete();
    219         }
    220         super.finalize();
    221     }
    222
    223     /**
    224      * Gets 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
    225      * and cached.
    226      *
    227      * @return The contents of the file as an array of bytes or {@code null} if the data cannot be read.
    228      * @throws UncheckedIOException if an I/O error occurs.
    229      * @throws OutOfMemoryError     if an array of the required size cannot be allocated, for example the file is larger that {@code 2GB}.
    230      */
    231     @Override
    232     public byte[] get() {
    233         if (isInMemory()) {
    234             if (cachedContent == null && dfos != null) {
    235                 cachedContent = dfos.getData();
    236             }
    237             return cachedContent != null ? cachedContent.clone() : new byte[0];
    238         }
    239         return Uncheck.get(() -> Files.readAllBytes(dfos.getFile().toPath()));
    240     }
    241
    242     /**
    243      * Gets the content charset passed by the agent or {@code null} if not defined.
    244      *
    245      * @return The content charset passed by the agent or {@code null} if not defined.
    246      */
    247     public String getCharSet() {
    248         final ParameterParser parser = new ParameterParser();
    249         parser.setLowerCaseNames(true);
    250         // Parameter parser can handle null input
    251         final Map<String, String> params = parser.parse(getContentType(), ';');
    252         return params.get("charset");
    253     }
    254
    255     /**
    256      * Gets the content type passed by the agent or {@code null} if not defined.
    257      *
    258      * @return The content type passed by the agent or {@code null} if not defined.
    259      */
    260     @Override
    261     public String getContentType() {
    262         return contentType;
    263     }
    264
    265     /**
    266      * Gets the default charset for use when no explicit charset parameter is provided by the sender.
    267      *
    268      * @return the default charset
    269      */
    270     public String getDefaultCharset() {
    271         return defaultCharset;
    272     }
    273
    274     /**
    275      * Gets the name of the field in the multipart form corresponding to this file item.
    276      *
    277      * @return The name of the form field.
    278      * @see #setFieldName(String)
    279      */
    280     @Override
    281     public String getFieldName() {
    282         return fieldName;
    283     }
    284
    285     /**
    286      * Gets the file item headers.
    287      *
    288      * @return The file items headers.
    289      */
    290     @Override
    291     public FileItemHeaders getHeaders() {
    292         return headers;
    293     }
    294
    295     /**
    296      * Gets an {@link java.io.InputStream InputStream} that can be used to retrieve the contents of the file.
    297      *
    298      * @return An {@link java.io.InputStream InputStream} that can be used to retrieve the contents of the file.
    299      *
    300      * @throws IOException if an error occurs.
    301      */
    302     @Override
    303     public InputStream getInputStream() throws IOException {
    304         if (!isInMemory()) {
    305             return Files.newInputStream(dfos.getPath());
    306         }
    307         if (cachedContent == null) {
    308             cachedContent = dfos.getData();
    309         }
    310         return new ByteArrayInputStream(cachedContent);
    311     }
    312
    313     /**
    314      * Gets the original file name in the client's file system.
    315      *
    316      * @return The original file name in the client's file system.
    317      * @throws org.apache.commons.fileupload.InvalidFileNameException The file name contains a NUL character,
    318      *   which might be an indicator of a security attack. If you intend to
    319      *   use the file name anyways, catch the exception and use
    320      *   {@link org.apache.commons.fileupload.InvalidFileNameException#getName()}.
    321      */
    322     @Override
    323     public String getName() {
    324         return Streams.checkFileName(fileName);
    325     }
    326
    327     /**
    328      * Gets an {@link java.io.OutputStream OutputStream} that can be used for storing the contents of the file.
    329      *
    330      * @return An {@link java.io.OutputStream OutputStream} that can be used for storing the contents of the file.
    331      *
    332      * @throws IOException if an error occurs (never happens).
    333      */
    334     @Override
    335     public OutputStream getOutputStream() throws IOException {
    336         if (dfos == null) {
    337             final File outputFile = getTempFile();
    338             // @formatter:off
    339             dfos = DeferredFileOutputStream.builder()
    340                     .setThreshold(sizeThreshold)
    341                     .setOutputFile(outputFile)
    342                     .get();
    343             // @formatter:on
    344         }
    345         return dfos;
    346     }
    347
    348     /**
    349      * Gets the size of the file.
    350      *
    351      * @return The size of the file, in bytes.
    352      */
    353     @Override
    354     public long getSize() {
    355         if (size >= 0) {
    356             return size;
    357         }
    358         if (cachedContent != null) {
    359             return cachedContent.length;
    360         }
    361         if (dfos.isInMemory()) {
    362             return dfos.getData().length;
    363         }
    364         return dfos.getFile().length();
    365     }
    366
    367     /**
    368      * Gets the {@link java.io.File} object for the {@code FileItem}'s
    369      * data's temporary location on the disk. Note that for
    370      * {@code FileItem}s that have their data stored in memory,
    371      * this method will return {@code null}. When handling large
    372      * files, you can use {@link java.io.File#renameTo(java.io.File)} to
    373      * move the file to new location without copying the data, if the
    374      * source and destination locations reside within the same logical
    375      * volume.
    376      *
    377      * @return The data file, or {@code null} if the data is stored in memory.
    378      */
    379     public File getStoreLocation() {
    380         if (dfos == null) {
    381             return null;
    382         }
    383         if (isInMemory()) {
    384             return null;
    385         }
    386         return dfos.getFile();
    387     }
    388
    389     /**
    390      * Gets the contents of the file as a String, using the default character encoding. This method uses
    391      * {@link #get()} to retrieve the contents of the file.
    392      * <p>
    393      * <strong>TODO</strong> Consider making this method throw UnsupportedEncodingException.
    394      *
    395      * @return The contents of the file, as a string.
    396      */
    397     @Override
    398     public String getString() {
    399         final byte[] rawData = get();
    400         String charset = getCharSet();
    401         if (charset == null) {
    402             charset = defaultCharset;
    403         }
    404         try {
    405             return new String(rawData, charset);
    406         } catch (final UnsupportedEncodingException e) {
    407             return "";
    408         }
    409     }
    410
    411     /**
    412      * Gets the contents of the file as a String, using the specified encoding. This method uses {@link #get()} to
    413      * retrieve the contents of the file.
    414      *
    415      * @param charset The charset to use.
    416      * @return The contents of the file, as a string.
    417      * @throws UnsupportedEncodingException if the requested character encoding is not available.
    418      */
    419     @Override
    420     public String getString(final String charset) throws UnsupportedEncodingException {
    421         return new String(get(), charset);
    422     }
    423
    424     /**
    425      * Creates and returns a {@link java.io.File File} representing a uniquely named temporary file in the configured
    426      * repository path. The lifetime of the file is tied to the lifetime of the {@code FileItem} instance; the file will
    427      * be deleted when the instance is garbage collected.
    428      * <p>
    429      * <b>Note: Subclasses that override this method must ensure that they return the same File each time.</b>
    430      *
    431      * @return The {@link java.io.File File} to be used for temporary storage.
    432      */
    433     protected File getTempFile() {
    434         if (tempFile == null) {
    435             File tempDir = repository;
    436             if (tempDir == null) {
    437                 tempDir = new File(System.getProperty("java.io.tmpdir"));
    438             }
    439
    440             final String tempFileName = String.format("upload_%s_%s.tmp", UID, getUniqueId());
    441
    442             tempFile = new File(tempDir, tempFileName);
    443         }
    444         return tempFile;
    445     }
    446
    447     /**
    448      * Tests whether or not a {@code FileItem} instance represents a simple form field.
    449      *
    450      * @return {@code true} if the instance represents a simple form field; {@code false} if it represents an uploaded
    451      *             file.
    452      *
    453      * @see #setFormField(boolean)
    454      */
    455     @Override
    456     public boolean isFormField() {
    457         return formField;
    458     }
    459
    460     /**
    461      * Provides a hint as to whether or not the file contents will be read from memory.
    462      *
    463      * @return {@code true} if the file contents will be read from memory; {@code false} otherwise.
    464      */
    465     @Override
    466     public boolean isInMemory() {
    467         if (cachedContent != null) {
    468             return true;
    469         }
    470         return dfos.isInMemory();
    471     }
    472
    473     /**
    474      * Sets the default charset for use when no explicit charset parameter is provided by the sender.
    475      *
    476      * @param charset the default charset
    477      */
    478     public void setDefaultCharset(final String charset) {
    479         defaultCharset = charset;
    480     }
    481
    482     /**
    483      * Sets the field name used to reference this file item.
    484      *
    485      * @param fieldName The name of the form field.
    486      * @see #getFieldName()
    487      */
    488     @Override
    489     public void setFieldName(final String fieldName) {
    490         this.fieldName = fieldName;
    491     }
    492
    493     /**
    494      * Sets whether or not a {@code FileItem} instance represents a simple form field.
    495      *
    496      * @param formField {@code true} if the instance represents a simple form
    497      *              field; {@code false} if it represents an uploaded file.
    498      *
    499      * @see #isFormField()
    500      */
    501     @Override
    502     public void setFormField(final boolean formField) {
    503         this.formField = formField;
    504     }
    505
    506     /**
    507      * Sets the file item headers.
    508      *
    509      * @param headers The file items headers.
    510      */
    511     @Override
    512     public void setHeaders(final FileItemHeaders headers) {
    513         this.headers = headers;
    514     }
    515
    516     /**
    517      * Returns a string representation of this object.
    518      *
    519      * @return a string representation of this object.
    520      */
    521     @Override
    522     public String toString() {
    523         return String.format("name=%s, StoreLocation=%s, size=%s bytes, isFormField=%s, FieldName=%s",
    524                 getName(), getStoreLocation(), Long.valueOf(getSize()), Boolean.valueOf(isFormField()), getFieldName());
    525     }
    526
    527     /**
    528      * A convenience method to write an uploaded item to disk. The client code
    529      * is not concerned with whether or not the item is stored in memory, or on
    530      * disk in a temporary location. They just want to write the uploaded item
    531      * to a file.
    532      * <p>
    533      * This implementation first attempts to rename the uploaded item to the
    534      * specified destination file, if the item was originally written to disk.
    535      * Otherwise, the data will be copied to the specified file.
    536      * </p>
    537      * <p>
    538      * This method is only guaranteed to work <em>once</em>, the first time it
    539      * is invoked for a particular item. This is because, in the event that the
    540      * method renames a temporary file, that file will no longer be available
    541      * to copy or rename again at a later time.
    542      * </p>
    543      *
    544      * @param file The {@code File} into which the uploaded item should
    545      *             be stored.
    546      * @throws Exception if an error occurs.
    547      */
    548     @Override
    549     public void write(final File file) throws Exception {
    550         if (isInMemory()) {
    551             try (FileOutputStream fout = new FileOutputStream(file);) {
    552                 fout.write(get());
    553             } catch (final IOException ignore) {
    554                 // ignore
    555             }
    556         } else {
    557             final File outputFile = getStoreLocation();
    558             if (outputFile == null) {
    559                 /*
    560                  * For whatever reason we cannot write the file to disk.
    561                  */
    562                 throw new FileUploadException("Cannot write uploaded file to disk!");
    563             }
    564             // Save the length of the file
    565             size = outputFile.length();
    566             /*
    567              * The uploaded file is being stored on disk in a temporary location so move it to the desired file.
    568              */
    569             if (file.exists() && !file.delete()) {
    570                 throw new FileUploadException("Cannot write uploaded file to disk!");
    571             }
    572             FileUtils.moveFile(outputFile, file);
    573         }
    574     }
    575 }