Java tutorial
/* * 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.vfs2.provider.url; import org.apache.commons.vfs2.FileName; import org.apache.commons.vfs2.FileSystemException; import org.apache.commons.vfs2.provider.AbstractFileNameParser; import org.apache.commons.vfs2.provider.URLFileName; import org.apache.commons.vfs2.provider.URLFileNameParser; import org.apache.commons.vfs2.provider.VfsComponentContext; import org.apache.commons.vfs2.provider.local.GenericFileNameParser; /** * Implementation for any java.net.url based filesystem. * <p> * Composite of URLFilenameParser and GenericFilenameParser */ public class UrlFileNameParser extends AbstractFileNameParser { private final URLFileNameParser url = new URLFileNameParser(80); private final GenericFileNameParser generic = new GenericFileNameParser(); public UrlFileNameParser() { super(); } @Override public boolean encodeCharacter(final char ch) { return super.encodeCharacter(ch) || ch == '?'; } /** * Parse a URI. * @param context The component context. * @param base The base FileName. * @param uri The target file name. * @return The FileName. * @throws FileSystemException if an error occurs */ @Override public FileName parseUri(final VfsComponentContext context, final FileName base, final String uri) throws FileSystemException { if (isUrlBased(base, uri)) { return url.parseUri(context, base, uri); } return generic.parseUri(context, base, uri); } /** * Guess if the given file name is an URL with host or not. * <p> * VFS treats such URLs differently. * <p> * A file name is URL-based if the base is a {@code URLFileName} or there are only 2 slashes * after the scheme. * e.g: {@code http://host/path}, {@code file:/path/to/file}, {@code file:///path/to/file}. * @param base The filename is relative to this base. * @param filename The filename. * @return true if filename contains two slashes or base was URLFileName. */ protected boolean isUrlBased(final FileName base, final String filename) { if (base instanceof URLFileName) { return true; } return countSlashes(filename) == 2; } /** * This method counts the slashes after the scheme. * * @param filename The file name. * @return number of slashes */ protected int countSlashes(final String filename) { int state = 0; int nuofSlash = 0; for (int pos = 0; pos < filename.length(); pos++) { final char c = filename.charAt(pos); if (state == 0) { if (c >= 'a' && c <= 'z') { continue; } if (c == ':') { state++; continue; } } else if (state == 1) { if (c == '/') { nuofSlash++; } else { return nuofSlash; } } } return nuofSlash; } }