/* * Copyright (c) 1996, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.net; /** * Helper class to map URL "abbreviations" to real URLs. * The default implementation supports the following mappings: *   ftp.mumble.bar/... => ftp://ftp.mumble.bar/... *   gopher.mumble.bar/... => gopher://gopher.mumble.bar/... *   other.name.dom/... => http://other.name.dom/... *   /foo/... => file:/foo/... * * Full URLs (those including a protocol name) are passed through unchanged. * * Subclassers can override or extend this behavior to support different * or additional canonicalization policies. * * @author      Steve Byrne */ public class URLCanonicalizer {    /**     * Creates the default canonicalizer instance.     */    public URLCanonicalizer() { }     /**     * Given a possibly abbreviated URL (missing a protocol name, typically),     * this method's job is to transform that URL into a canonical form,     * by including a protocol name and additional syntax, if necessary.     *     * For a correctly formed URL, this method should just return its argument.     */    public String canonicalize(String simpleURL) {        String resultURL = simpleURL;        if (simpleURL.startsWith("ftp.")) {            resultURL = "ftp://" + simpleURL;        } else if (simpleURL.startsWith("gopher.")) {            resultURL = "gopher://" + simpleURL;        } else if (simpleURL.startsWith("/")) {            resultURL = "file:" + simpleURL;        } else if (!hasProtocolName(simpleURL)) {            if (isSimpleHostName(simpleURL)) {                simpleURL = "www." + simpleURL + ".com";            }            resultURL = "http://" + simpleURL;        }         return resultURL;    }     /**     * Given a possibly abbreviated URL, this predicate function returns     * true if it appears that the URL contains a protocol name     */    public boolean hasProtocolName(String url) {        int index = url.indexOf(':');        if (index <= 0) {       // treat ":foo" as not having a protocol spec            return false;        }         for (int i = 0; i < index; i++) {            char c = url.charAt(i);             // REMIND: this is a guess at legal characters in a protocol --            // need to be verified            if ((c >= 'A' && c <= 'Z')                || (c >= 'a' && c <= 'z')                || (c == '-')) {                continue;            }             // found an illegal character            return false;        }         return true;    }     /**     * Returns true if the URL is just a single name, no periods or     * slashes, false otherwise     **/    protected boolean isSimpleHostName(String url) {         for (int i = 0; i < url.length(); i++) {            char c = url.charAt(i);             // REMIND: this is a guess at legal characters in a protocol --            // need to be verified            if ((c >= 'A' && c <= 'Z')                || (c >= 'a' && c <= 'z')                || (c >= '0' && c <= '9')                || (c == '-')) {                continue;            }             // found an illegal character            return false;        }         return true;    }}