001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.configuration2.io;
018
019import java.io.File;
020import java.io.InputStream;
021import java.io.OutputStream;
022import java.net.MalformedURLException;
023import java.net.URL;
024
025import org.apache.commons.configuration2.ex.ConfigurationException;
026
027/**
028 * Abstract layer to allow various types of file systems.
029 * @since 1.7
030 */
031public abstract class FileSystem
032{
033    /** Constant for the default logger. */
034    private static final ConfigurationLogger DEFAULT_LOG = ConfigurationLogger.newDummyLogger();
035
036    /** The Logger */
037    private volatile ConfigurationLogger log;
038
039    /** FileSystem options provider */
040    private volatile FileOptionsProvider optionsProvider;
041
042    /**
043     * Returns the logger used by this FileSystem.
044     *
045     * @return the logger
046     */
047    public ConfigurationLogger getLogger()
048    {
049        final ConfigurationLogger result = log;
050        return result != null ? result : DEFAULT_LOG;
051    }
052
053    /**
054     * Allows setting the logger to be used by this FileSystem. This
055     * method makes it possible for clients to exactly control logging behavior.
056     * Per default a logger is set that will ignore all log messages. Derived
057     * classes that want to enable logging should call this method during their
058     * initialization with the logger to be used. Passing in a <b>null</b> argument
059     * disables logging.
060     *
061     * @param log the new logger
062     */
063    public void setLogger(final ConfigurationLogger log)
064    {
065        this.log = log;
066    }
067
068    /**
069     * Set the FileOptionsProvider
070     * @param provider The FileOptionsProvider
071     */
072    public void setFileOptionsProvider(final FileOptionsProvider provider)
073    {
074        this.optionsProvider = provider;
075    }
076
077    public FileOptionsProvider getFileOptionsProvider()
078    {
079        return this.optionsProvider;
080    }
081
082    public abstract InputStream getInputStream(URL url) throws ConfigurationException;
083
084    public abstract OutputStream getOutputStream(URL url) throws ConfigurationException;
085
086    public abstract OutputStream getOutputStream(File file) throws ConfigurationException;
087
088    public abstract String getPath(File file, URL url, String basePath, String fileName);
089
090    public abstract String getBasePath(String path);
091
092    public abstract String getFileName(String path);
093
094    public abstract URL locateFromURL(String basePath, String fileName);
095
096    public abstract URL getURL(String basePath, String fileName) throws MalformedURLException;
097}