org.apache.cxf.staxutils.DepthRestrictingStreamReader Maven / Gradle / Ivy
/**
* 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.cxf.staxutils;
import java.util.Stack;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
/**
* XMLStreamReader implementation which can be used to enforce a number of
* depth-restricting policies. The following properties are currently supported:
* - total number of elements in the document
* - the maximum depth of the given element; the root element will be checked by default
* - the maximum number of immediate child nodes for individual elements
*
* More sophisticated policies can be supported in the future.
*/
public class DepthRestrictingStreamReader extends DepthXMLStreamReader {
private DocumentDepthProperties props;
private int totalElementCount;
private Stack stack = new Stack();
public DepthRestrictingStreamReader(XMLStreamReader reader,
int elementCountThreshold,
int innerElementLevelThreshold,
int innerElementCountThreshold) {
this(reader, new DocumentDepthProperties(elementCountThreshold,
innerElementLevelThreshold,
innerElementCountThreshold));
}
public DepthRestrictingStreamReader(XMLStreamReader reader,
DocumentDepthProperties props) {
super(reader);
this.props = props;
}
@Override
public int next() throws XMLStreamException {
int next = super.next();
if (next == START_ELEMENT) {
if (props.getInnerElementLevelThreshold() != -1
&& getDepth() >= props.getInnerElementLevelThreshold()) {
throw new DepthExceededStaxException();
}
if (props.getElementCountThreshold() != -1
&& ++totalElementCount >= props.getElementCountThreshold()) {
throw new DepthExceededStaxException();
}
if (props.getInnerElementCountThreshold() != -1) {
if (!stack.empty()) {
int currentCount = stack.pop();
if (++currentCount >= props.getInnerElementCountThreshold()) {
throw new DepthExceededStaxException();
} else {
stack.push(currentCount);
}
}
stack.push(0);
}
} else if (next == END_ELEMENT && props.getInnerElementCountThreshold() != -1) {
stack.pop();
}
return next;
}
}