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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.vfs.provider;
    18
    19  import org.apache.commons.vfs.FileName;
    20  import org.apache.commons.vfs.FileObject;
    21  import org.apache.commons.vfs.FileSystem;
    22  import org.apache.commons.vfs.FileSystemException;
    23  import org.apache.commons.vfs.FileSystemOptions;
    24
    25  /***
    26   * A {@link FileProvider} that handles physical files, such as the files in a
    27   * local fs, or on an FTP server.  An originating file system cannot be
    28   * layered on top of another file system.
    29   *
    30   * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
    31   * @version $Revision: 480428 $ $Date: 2006-11-29 07:15:24 +0100 (Mi, 29 Nov 2006) $
    32   */
    33  public abstract class AbstractOriginatingFileProvider
    34      extends AbstractFileProvider
    35  {
    36      public AbstractOriginatingFileProvider()
    37      {
    38          super();
    39      }
    40
    41      /***
    42       * Locates a file object, by absolute URI.
    43       *
    44       * @param uri
    45       */
    46      public FileObject findFile(final FileObject baseFile,
    47                                 final String uri,
    48                                 final FileSystemOptions fileSystemOptions) throws FileSystemException
    49      {
    50          // Parse the URI
    51          final FileName name;
    52          try
    53          {
    54              name = parseUri(baseFile!=null?baseFile.getName():null, uri);
    55          }
    56          catch (FileSystemException exc)
    57          {
    58              throw new FileSystemException("vfs.provider/invalid-absolute-uri.error", uri, exc);
    59          }
    60
    61          // Locate the file
    62          return findFile(name, fileSystemOptions);
    63      }
    64
    65      /***
    66       * Locates a file from its parsed URI.
    67       */
    68      protected FileObject findFile(final FileName name, final FileSystemOptions fileSystemOptions)
    69          throws FileSystemException
    70      {
    71  		// Check in the cache for the file system
    72  		final FileName rootName = getContext().getFileSystemManager().resolveName(name, FileName.ROOT_PATH);
    73
    74  		FileSystem fs;
    75  		synchronized (this)
    76  		{
    77  			fs = findFileSystem(rootName, fileSystemOptions);
    78  			if (fs == null)
    79  			{
    80  				// Need to create the file system, and cache it
    81  				fs = doCreateFileSystem(rootName, fileSystemOptions);
    82  				addFileSystem(rootName, fs);
    83  			}
    84  		}
    85
    86  		// Locate the file
    87          // return fs.resolveFile(name.getPath());
    88          return fs.resolveFile(name);
    89      }
    90
    91      /***
    92       * Creates a {@link FileSystem}.  If the returned FileSystem implements
    93       * {@link VfsComponent}, it will be initialised.
    94       *
    95       * @param rootName The name of the root file of the file system to create.
    96       */
    97      protected abstract FileSystem doCreateFileSystem(final FileName rootName, final FileSystemOptions fileSystemOptions)
    98          throws FileSystemException;
    99  }