/*
* 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 io.milton.http.webdav;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Stack;
import javax.xml.namespace.QName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class PropPatchSaxHandler extends DefaultHandler
{
private final static Logger log = LoggerFactory.getLogger(PropPatchSaxHandler.class);
private final static QName SET = new QName(WebDavProtocol.DAV_URI, "set");
private final static QName REMOVE = new QName(WebDavProtocol.DAV_URI, "remove");
private final static QName PROP = new QName(WebDavProtocol.DAV_URI, "prop");
private final Stack<StateHandler> handlers = new Stack<StateHandler>();
private final Map<QName, String> attributesSet = new LinkedHashMap<QName, String>();
private final Map<QName, String> attributesRemove = new LinkedHashMap<QName, String>();
@Override
public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException
{
QName qname = new QName(uri, localName);
StateHandler handler;
if (!handlers.isEmpty())
handler = handlers.peek().startChild(qname, attributes);
else
handler = new Root(attributesSet, attributesRemove);
handlers.push(handler);
super.startElement(uri, localName, name, attributes);
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException
{
handlers.peek().characters(ch, start, length);
}
@Override
public void endElement(String uri, String localName, String name) throws SAXException
{
QName qname = new QName(uri, localName);
StateHandler handler = handlers.pop();
handler.endSelf(qname);
super.endElement(uri, localName, name);
}
public Map<QName, String> getAttributesToSet()
{
return attributesSet;
}
public Map<QName, String> getAttributesToRemove()
{
return attributesRemove;
}
/**
* Abstract class to handle SAX events for the various states
* that we expect to encounter while parsing a PROPATCH XML
* document.
*/
private static abstract class StateHandler
{
public abstract StateHandler startChild(QName name, Attributes attributes)
throws SAXException;
public void endSelf(QName name)
throws SAXException
{
}
public void characters(char[] ch, int start, int length)
throws SAXException
{
}
public static StateHandler Ignore = new StateHandler()
{
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
return this;
}
};
}
/**
* State handler for the root element of a PROPPATCH request. This
* expects to get either a "set" or "remove" element and ignores
* any other content.
*/
private static class Root extends StateHandler
{
private final Map<QName, String> set;
private final Map<QName, String> remove;
private Root(Map<QName, String> set, Map<QName, String> remove)
{
this.set = set;
this.remove = remove;
}
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
if (name.equals(SET))
return new Op(set);
if (name.equals(REMOVE))
return new Op(remove);
return StateHandler.Ignore;
}
}
/**
* State handler for a "set" or "remove" child or a PROPPATCH request.
* This expects to get a "prop" as a child element and ignores all
* others.
*/
private static class Op extends StateHandler
{
private final Map<QName, String> values;
private Op(Map<QName, String> values)
{
this.values = values;
}
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
if (name.equals(PROP))
return new Prop(values);
return StateHandler.Ignore;
}
}
/**
* State handler for the "prop" element beneath a "set" or "remove" in
* a PROPPATCH request. It treats children as individual attributes
* to be recorded in it's value map.
*/
private static class Prop extends StateHandler
{
private final Map<QName, String> values;
private Prop(Map<QName, String> values)
{
this.values = values;
}
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
return new Attribute(values);
}
}
/**
* Attribute to be set or removed in a PROPPATCH request. It's content
* and any child elements will be stringified and added to either the
* set or remove attribute maps.
*/
private static class Attribute extends StateHandler
{
private final Map<QName, String> values;
private final Content content = new Content();
private Attribute(Map<QName, String> values)
{
this.values = values;
}
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
content.startChild(name, attributes);
return content;
}
@Override
public void endSelf(QName name) throws SAXException
{
values.put(name, content.getValue().trim());
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException
{
content.characters(ch, start, length);
}
}
/**
* Attribute content. All character data and sub-elements are
* appended to a string buffer.
*/
private static class Content extends StateHandler
{
private final StringBuilder value = new StringBuilder();
@Override
public StateHandler startChild(QName name, Attributes attributes) throws SAXException
{
value.append("<").append(name.getLocalPart());
if(attributes != null)
{
for(int i = 0; i < attributes.getLength(); i++)
{
value.append(" ");
value.append(attributes.getLocalName(i));
value.append("=\"");
value.append(attributes.getValue(i));
value.append("\"");
}
}
value.append(">");
return this;
}
@Override
public void endSelf(QName name) throws SAXException
{
if(value.charAt(value.length() - 1) == '>')
{
value.insert(value.length() - 1, '/');
}
else
{
value.append("</").append(name.getLocalPart()).append(">");
}
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException
{
value.append(new String(ch, start, length));
}
public String getValue()
{
return value.toString();
}
}
}