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Jakarta Standard Tag Library Implementation
/*
* Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.taglibs.standard.extra.spath;
/**
* Represents a predicate expression concerning a single attribute.
*
* @author Shawn Bayern
*/
public class AttributePredicate extends Predicate {
private String attribute, target;
/**
* Constructs a new AttributePredicate, given an attribute name
* and a target literal (with which to test equality).
*/
public AttributePredicate(String attribute, String target) {
if (attribute == null)
throw new IllegalArgumentException("non-null attribute needed");
if (attribute.indexOf(":") != -1)
throw new IllegalArgumentException(
"namespace-qualified attribute names are not currently " +
"supported");
this.attribute = attribute;
if (target == null)
throw new IllegalArgumentException("non-null target needed");
// strip quotation marks from target
this.target = target.substring(1, target.length() - 1);
}
/**
* Returns true if the given SAX AttributeList is suitable, given our
* attribute name and target; returns false otherwise.
*/
public boolean isMatchingAttribute(org.xml.sax.Attributes a) {
String attValue = a.getValue("", attribute);
return (attValue != null && attValue.equals(target));
}
}