/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.configuration;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.impl.NoOpLog;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.File;
import java.net.URL;
import java.net.MalformedURLException;
/**
* Abstract layer to allow various types of file systems.
* @since 1.7
* @author <a
* href="http://commons.apache.org/configuration/team-list.html">Commons Configuration team</a>
*/
public abstract class FileSystem
{
/** The name of the system property that can be used to set the file system class name */
private static final String FILE_SYSTEM = "org.apache.commons.configuration.filesystem";
/** The default file system */
private static FileSystem fileSystem;
/** The Logger */
private Log log;
/** FileSystem options provider */
private FileOptionsProvider optionsProvider;
public FileSystem()
{
setLogger(null);
}
/**
* Returns the logger used by this FileSystem.
*
* @return the logger
*/
public Log getLogger()
{
return log;
}
/**
* Allows to set the logger to be used by this FileSystem. This
* method makes it possible for clients to exactly control logging behavior.
* Per default a logger is set that will ignore all log messages. Derived
* classes that want to enable logging should call this method during their
* initialization with the logger to be used.
*
* @param log the new logger
*/
public void setLogger(Log log)
{
this.log = (log != null) ? log : new NoOpLog();
}
static
{
String fsClassName = System.getProperty(FILE_SYSTEM);
if (fsClassName != null)
{
Log log = LogFactory.getLog(FileSystem.class);
try
{
Class clazz = Class.forName(fsClassName);
if (FileSystem.class.isAssignableFrom(clazz))
{
fileSystem = (FileSystem) clazz.newInstance();
if (log.isDebugEnabled())
{
log.debug("Using " + fsClassName);
}
}
}
catch (InstantiationException ex)
{
log.error("Unable to create " + fsClassName, ex);
}
catch (IllegalAccessException ex)
{
log.error("Unable to create " + fsClassName, ex);
}
catch (ClassNotFoundException ex)
{
log.error("Unable to create " + fsClassName, ex);
}
}
if (fileSystem == null)
{
fileSystem = new DefaultFileSystem();
}
}
/**
* Set the FileSystem to use.
* @param fs The FileSystem
* @throws NullPointerException if the FileSystem parameter is null.
*/
public static void setDefaultFileSystem(FileSystem fs) throws NullPointerException
{
if (fs == null)
{
throw new NullPointerException("A FileSystem implementation is required");
}
fileSystem = fs;
}
/**
* Reset the FileSystem to the default.
*/
public static void resetDefaultFileSystem()
{
fileSystem = new DefaultFileSystem();
}
/**
* Retrieve the FileSystem being used.
* @return The FileSystem.
*/
public static FileSystem getDefaultFileSystem()
{
return fileSystem;
}
/**
* Set the FileOptionsProvider
* @param provider The FileOptionsProvider
*/
public void setFileOptionsProvider(FileOptionsProvider provider)
{
this.optionsProvider = provider;
}
public FileOptionsProvider getFileOptionsProvider()
{
return this.optionsProvider;
}
public abstract InputStream getInputStream(String basePath, String fileName)
throws ConfigurationException;
public abstract InputStream getInputStream(URL url) throws ConfigurationException;
public abstract OutputStream getOutputStream(URL url) throws ConfigurationException;
public abstract OutputStream getOutputStream(File file) throws ConfigurationException;
public abstract String getPath(File file, URL url, String basePath, String fileName);
public abstract String getBasePath(String path);
public abstract String getFileName(String path);
public abstract URL locateFromURL(String basePath, String fileName);
public abstract URL getURL(String basePath, String fileName) throws MalformedURLException;
}
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