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.vfs2.provider.local;
018
019import java.net.URI;
020
021import org.apache.commons.vfs2.FileName;
022import org.apache.commons.vfs2.FileSystemException;
023import org.apache.commons.vfs2.FileType;
024import org.apache.commons.vfs2.provider.AbstractFileNameParser;
025import org.apache.commons.vfs2.provider.UriParser;
026import org.apache.commons.vfs2.provider.VfsComponentContext;
027
028/**
029 * A name parser.
030 */
031public abstract class LocalFileNameParser extends AbstractFileNameParser {
032
033    /**
034     * Constructs a new instance.
035     */
036    public LocalFileNameParser() {
037        // empty
038    }
039
040    /**
041     * Creates a FileName.
042     *
043     * @param scheme The scheme.
044     * @param rootFile the root file.
045     * @param path the path.
046     * @param fileType the file type.
047     * @return a FileName.
048     */
049    protected abstract FileName createFileName(String scheme, String rootFile, String path, FileType fileType);
050
051    /**
052     * Pops the root prefix off a URI, which has had the scheme removed.
053     *
054     * @param name the URI to modify.
055     * @param uri the whole URI for error reporting.
056     * @return the root prefix extracted.
057     * @throws FileSystemException if an error occurs.
058     */
059    protected abstract String extractRootPrefix(String uri, StringBuilder name) throws FileSystemException;
060
061    private String[] getSchemes(final VfsComponentContext context, final FileName base, final String uri) {
062        if (context == null) {
063            return new String[] {base != null ? base.getScheme() : URI.create(uri).getScheme()};
064        }
065        return context.getFileSystemManager().getSchemes();
066    }
067
068    /**
069     * Determines if a name is an absolute file name.
070     *
071     * @param name The file name.
072     * @return true if the name is absolute, false otherwise.
073     */
074    public boolean isAbsoluteName(final String name) {
075        // TODO - this is yucky
076        final StringBuilder b = new StringBuilder(name);
077        try {
078            UriParser.fixSeparators(b);
079            extractRootPrefix(name, b);
080            return true;
081        } catch (final FileSystemException e) {
082            return false;
083        }
084    }
085
086    @Override
087    public FileName parseUri(final VfsComponentContext context, final FileName base, final String uri)
088            throws FileSystemException {
089        final StringBuilder nameBuilder = new StringBuilder();
090
091        // Extract the scheme
092        String scheme = UriParser.extractScheme(getSchemes(context, base, uri), uri, nameBuilder);
093        if (scheme == null && base != null) {
094            scheme = base.getScheme();
095        }
096        if (scheme == null) {
097            scheme = "file";
098        }
099
100        // Remove encoding, and adjust the separators
101        UriParser.canonicalizePath(nameBuilder, 0, nameBuilder.length(), this);
102
103        UriParser.fixSeparators(nameBuilder);
104
105        // Extract the root prefix
106        final String rootFile = extractRootPrefix(uri, nameBuilder);
107
108        // Normalise the path
109        final FileType fileType = UriParser.normalisePath(nameBuilder);
110
111        final String path = nameBuilder.toString();
112
113        return createFileName(scheme, rootFile, path, fileType);
114    }
115}