/*
 * 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.configuration2.io;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.commons.configuration2.ex.ConfigurationException;

Abstract layer to allow various types of file systems.
Since:
1.7/**
 * Abstract layer to allow various types of file systems.
 * @since 1.7
 */
public abstract class FileSystem
{
    
Constant for the default logger. /** Constant for the default logger. */
    private static final ConfigurationLogger DEFAULT_LOG = ConfigurationLogger.newDummyLogger();

    
The Logger /** The Logger */
    private volatile ConfigurationLogger log;

    
FileSystem options provider /** FileSystem options provider */
    private volatile FileOptionsProvider optionsProvider;

    
Returns the logger used by this FileSystem.
Returns:
the logger/**
     * Returns the logger used by this FileSystem.
     *
     * @return the logger
     */
    public ConfigurationLogger getLogger()
    {
        final ConfigurationLogger result = log;
        return result != null ? result : DEFAULT_LOG;
    }

    
Allows setting 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. Passing in a null argument
disables logging.
Params:
log – the new logger/**
     * Allows setting 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. Passing in a <b>null</b> argument
     * disables logging.
     *
     * @param log the new logger
     */
    public void setLogger(final ConfigurationLogger log)
    {
        this.log = log;
    }

    
Set the FileOptionsProvider
Params:
provider – The FileOptionsProvider/**
     * Set the FileOptionsProvider
     * @param provider The FileOptionsProvider
     */
    public void setFileOptionsProvider(final FileOptionsProvider provider)
    {
        this.optionsProvider = provider;
    }

    public FileOptionsProvider getFileOptionsProvider()
    {
        return this.optionsProvider;
    }

    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;
}