/*
* $Id: XmlNames.java,v 1.3 2001/03/16 04:01:34 edwingo Exp $
*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Crimson" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Sun Microsystems, Inc.,
* http://www.sun.com. For more information on the Apache Software
* Foundation, please see <http://www.apache.org/>.
*/
package com.sun.imageio.metadata;
/**
* This class contains static methods used to determine whether identifiers
* may appear in certain roles in XML documents. Such methods are used
* both to parse and to create such documents.
*
* @version 1.4
* @author David Brownell
*/
public class XmlNames
{
/**
* Useful strings from the DOM Level 2 Spec
*/
public static final String
SPEC_XML_URI = "http://www.w3.org/XML/1998/namespace";
public static final String
SPEC_XMLNS_URI = "http://www.w3.org/2000/xmlns/";
private XmlNames () { }
/**
* Returns true if the value is a legal XML name.
*
* @param value the string being tested
*/
public static boolean isName (String value)
{
if (value == null || "".equals(value))
return false;
char c = value.charAt (0);
if (!XmlChars.isLetter (c) && c != '_' && c != ':')
return false;
for (int i = 1; i < value.length (); i++)
if (!XmlChars.isNameChar (value.charAt (i)))
return false;
return true;
}
/**
* Returns true if the value is a legal "unqualified" XML name, as
* defined in the XML Namespaces proposed recommendation.
* These are normal XML names, except that they may not contain
* a "colon" character.
*
* @param value the string being tested
*/
public static boolean isUnqualifiedName (String value)
{
if (value == null || value.length() == 0)
return false;
char c = value.charAt (0);
if (!XmlChars.isLetter (c) && c != '_')
return false;
for (int i = 1; i < value.length (); i++)
if (!XmlChars.isNCNameChar (value.charAt (i)))
return false;
return true;
}
/**
* Returns true if the value is a legal "qualified" XML name, as defined
* in the XML Namespaces proposed recommendation. Qualified names are
* composed of an optional prefix (an unqualified name), followed by a
* colon, and a required "local part" (an unqualified name). Prefixes are
* declared, and correspond to particular URIs which scope the "local
* part" of the name. (This method cannot check whether the prefix of a
* name has been declared.)
*
* @param value the string being tested
*/
public static boolean isQualifiedName (String value)
{
if (value == null)
return false;
// [6] QName ::= (Prefix ':')? LocalPart
// [7] Prefix ::= NCName
// [8] LocalPart ::= NCName
int first = value.indexOf (':');
// no Prefix, only check LocalPart
if (first <= 0)
return isUnqualifiedName (value);
// Prefix exists, check everything
int last = value.lastIndexOf (':');
if (last != first)
return false;
return isUnqualifiedName (value.substring (0, first))
&& isUnqualifiedName (value.substring (first + 1));
}
/**
* This method returns true if the identifier is a "name token"
* as defined in the XML specification. Like names, these
* may only contain "name characters"; however, they do not need
* to have letters as their initial characters. Attribute values
* defined to be of type NMTOKEN(S) must satisfy this predicate.
*
* @param token the string being tested
*/
public static boolean isNmtoken (String token)
{
int length = token.length ();
for (int i = 0; i < length; i++)
if (!XmlChars.isNameChar (token.charAt (i)))
return false;
return true;
}
/**
* This method returns true if the identifier is a "name token" as
* defined by the XML Namespaces proposed recommendation.
* These are like XML "name tokens" but they may not contain the
* "colon" character.
*
* @see #isNmtoken
*
* @param token the string being tested
*/
public static boolean isNCNmtoken (String token)
{
return isNmtoken (token) && token.indexOf (':') < 0;
}
/**
* Return the Prefix of qualifiedName. Does not check that Prefix is a
* valid NCName.
*
* @param qualifiedName name to find the Prefix of
* @return prefix or null if it has none
*/
public static String getPrefix(String qualifiedName) {
// [6] QName ::= (Prefix ':')? LocalPart
// [7] Prefix ::= NCName
int index = qualifiedName.indexOf(':');
return index <= 0 ? null : qualifiedName.substring(0, index);
}
/**
* Return the LocalPart of qualifiedName. Does not check that Prefix is a
* valid NCName.
*
* @param qualifiedName name to find the LocalPart of
* @return LocalPart or null if it has none
*/
public static String getLocalPart(String qualifiedName) {
// [6] QName ::= (Prefix ':')? LocalPart
// [8] LocalPart ::= NCName
int index = qualifiedName.indexOf(':');
if (index < 0) {
return qualifiedName;
}
// ':' at end of qualifiedName
if (index == qualifiedName.length() - 1) {
return null;
}
return qualifiedName.substring(index + 1);
}
}
|
