/*
* 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.jasper.util;
import java.util.HashSet;
import java.util.Set;
import org.apache.jasper.compiler.Localizer;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.AttributesImpl;
/**
* Wraps the default attributes implementation and ensures that each attribute has a unique qname as required by the JSP
* specification.
*/
public class UniqueAttributesImpl extends AttributesImpl {
private static final String IMPORT = "import";
private static final String PAGE_ENCODING = "pageEncoding";
private final boolean pageDirective;
private final Set<String> qNames = new HashSet<>();
public UniqueAttributesImpl() {
this.pageDirective = false;
}
public UniqueAttributesImpl(boolean pageDirective) {
this.pageDirective = pageDirective;
}
@Override
public void clear() {
qNames.clear();
super.clear();
}
@Override
public void setAttributes(Attributes atts) {
for (int i = 0; i < atts.getLength(); i++) {
if (!qNames.add(atts.getQName(i))) {
handleDuplicate(atts.getQName(i), atts.getValue(i));
}
}
super.setAttributes(atts);
}
@Override
public void addAttribute(String uri, String localName, String qName, String type, String value) {
if (qNames.add(qName)) {
super.addAttribute(uri, localName, qName, type, value);
} else {
handleDuplicate(qName, value);
}
}
@Override
public void setAttribute(int index, String uri, String localName, String qName, String type, String value) {
qNames.remove(super.getQName(index));
if (qNames.add(qName)) {
super.setAttribute(index, uri, localName, qName, type, value);
} else {
handleDuplicate(qName, value);
}
}
@Override
public void removeAttribute(int index) {
qNames.remove(super.getQName(index));
super.removeAttribute(index);
}
@Override
public void setQName(int index, String qName) {
qNames.remove(super.getQName(index));
super.setQName(index, qName);
}
private void handleDuplicate(String qName, String value) {
if (pageDirective) {
if (IMPORT.equalsIgnoreCase(qName)) {
// Always merge imports
int i = super.getIndex(IMPORT);
String v = super.getValue(i);
super.setValue(i, v + "," + value);
return;
} else if (PAGE_ENCODING.equalsIgnoreCase(qName)) {
// Page encoding can only occur once per file so a second
// attribute - even one with a duplicate value - is an error
} else {
// Other attributes can be repeated if and only if the values
// are identical
String v = super.getValue(qName);
if (v.equals(value)) {
return;
}
}
}
// Ordinary tag attributes can't be repeated, even with identical values
throw new IllegalArgumentException(Localizer.getMessage("jsp.error.duplicateqname", qName));
}
}