/*
* Copyright 2002-2005 The Apache Software Foundation.
*
* Licensed 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.vfs.provider;
import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystem;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.FileSystemOptions;
/**
* A {@link FileProvider} that handles physical files, such as the files in a
* local fs, or on an FTP server. An originating file system cannot be
* layered on top of another file system.
*
* @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
*/
public abstract class AbstractOriginatingFileProvider
extends AbstractFileProvider
{
public AbstractOriginatingFileProvider()
{
super();
}
/**
* Locates a file object, by absolute URI.
*
* @param uri
*/
public FileObject findFile(final FileObject baseFile,
final String uri,
final FileSystemOptions fileSystemOptions) throws FileSystemException
{
// Parse the URI
final FileName name;
try
{
name = parseUri(baseFile!=null?baseFile.getName():null, uri);
}
catch (FileSystemException exc)
{
throw new FileSystemException("vfs.provider/invalid-absolute-uri.error", uri, exc);
}
// Locate the file
return findFile(name, fileSystemOptions);
}
/**
* Locates a file from its parsed URI.
*/
protected synchronized FileObject findFile(final FileName name, final FileSystemOptions fileSystemOptions)
throws FileSystemException
{
// Check in the cache for the file system
final FileName rootName = getContext().getFileSystemManager().resolveName(name, FileName.ROOT_PATH);
FileSystem fs = findFileSystem(rootName, fileSystemOptions);
if (fs == null)
{
// Need to create the file system, and cache it
fs = doCreateFileSystem(rootName, fileSystemOptions);
addFileSystem(rootName, fs);
}
// Locate the file
return fs.resolveFile(name.getPath());
}
/**
* Creates a {@link FileSystem}. If the returned FileSystem implements
* {@link VfsComponent}, it will be initialised.
*
* @param rootName The name of the root file of the file system to create.
*/
protected abstract FileSystem doCreateFileSystem(final FileName rootName, final FileSystemOptions fileSystemOptions)
throws FileSystemException;
}