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.res;
018
019import org.apache.commons.lang3.StringUtils;
020import org.apache.commons.vfs2.FileName;
021import org.apache.commons.vfs2.FileSystemException;
022import org.apache.commons.vfs2.FileType;
023import org.apache.commons.vfs2.provider.local.GenericFileNameParser;
024
025/**
026 * Slightly modified file name parser for resource URIs.
027 */
028public class ResourceFileNameParser extends GenericFileNameParser {
029
030    private static final ResourceFileNameParser INSTANCE = new ResourceFileNameParser();
031
032    /**
033     * Gets the singleton instance.
034     *
035     * @return the singleton instance.
036     */
037    public static GenericFileNameParser getInstance() {
038        return INSTANCE;
039    }
040
041    /**
042     * Constructs a new instance.
043     */
044    public ResourceFileNameParser() {
045        // empty
046    }
047
048    @Override
049    protected FileName createFileName(final String scheme, final String rootFile, final String path,
050            final FileType type) {
051        return new ResourceFileName(scheme, path, type);
052    }
053
054    @Override
055    protected String extractRootPrefix(final String uri, final StringBuilder name) throws FileSystemException {
056        // Resource URI (as used by ClassLoader.getResource()) are assumed to be absolute despite
057        // lacking a leading '/'. All leading '/' will be stripped from the name.
058
059        int index = 0;
060        while (index < name.length() && name.charAt(index) == '/') {
061            ++index;
062        }
063        if (index > 0) {
064            name.delete(0, index);
065        }
066
067        if (StringUtils.isEmpty(name)) {
068            throw new FileSystemException("vfs.provider.res/not-valid-resource-location.error", uri);
069        }
070
071        return "/";
072    }
073}