/*
* 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
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*/
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;
}
}