/*
* 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.axiom.util.stax.xop;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import javax.activation.DataHandler;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import org.apache.axiom.ext.stax.datahandler.DataHandlerWriter;
import org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper;
/**
* {@link XMLStreamWriter} wrapper that decodes XOP. It assumes that the underlying stream
* implements the {@link DataHandlerWriter} extension and translates calls that write
* <tt>xop:Include</tt> elements into calls to the appropriate methods defined by
* {@link DataHandlerWriter}.
*/
public class XOPDecodingStreamWriter extends XMLStreamWriterWrapper {
private final MimePartProvider mimePartProvider;
private final DataHandlerWriter dataHandlerWriter;
private boolean inXOPInclude;
private String contentID;
/**
* Constructor.
*
* @param parent
* the {@link XMLStreamWriter} to write the decoded stream to; the instance must
* implement the {@link DataHandlerWriter} extension
* @param mimePartProvider
* an implementation of the {@link MimePartProvider} interface that will be used to
* load the {@link DataHandler} objects for MIME parts referenced by
* <tt>xop:Include</tt> element information items written to this wrapper
*/
public XOPDecodingStreamWriter(XMLStreamWriter parent, MimePartProvider mimePartProvider) {
super(parent);
this.mimePartProvider = mimePartProvider;
dataHandlerWriter = (DataHandlerWriter)parent.getProperty(DataHandlerWriter.PROPERTY);
}
public void writeStartElement(String prefix, String localName, String namespaceURI)
throws XMLStreamException {
if (localName.equals(XOPConstants.INCLUDE)
&& namespaceURI.equals(XOPConstants.NAMESPACE_URI)) {
inXOPInclude = true;
} else {
super.writeStartElement(prefix, localName, namespaceURI);
}
}
public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
if (localName.equals(XOPConstants.INCLUDE)
&& namespaceURI.equals(XOPConstants.NAMESPACE_URI)) {
inXOPInclude = true;
} else {
super.writeStartElement(namespaceURI, localName);
}
}
public void writeAttribute(String prefix, String namespaceURI, String localName, String value)
throws XMLStreamException {
if (inXOPInclude) {
processAttribute(namespaceURI, localName, value);
} else {
super.writeAttribute(prefix, namespaceURI, localName, value);
}
}
public void writeAttribute(String namespaceURI, String localName, String value)
throws XMLStreamException {
if (inXOPInclude) {
processAttribute(namespaceURI, localName, value);
} else {
super.writeAttribute(namespaceURI, localName, value);
}
}
public void writeAttribute(String localName, String value) throws XMLStreamException {
if (inXOPInclude) {
processAttribute(null, localName, value);
} else {
super.writeAttribute(localName, value);
}
}
private void processAttribute(String namespaceURI, String localName, String value)
throws XMLStreamException {
if ((namespaceURI == null || namespaceURI.length() == 0)
&& localName.equals(XOPConstants.HREF)) {
if (!value.startsWith("cid:")) {
throw new XMLStreamException("Expected href attribute containing a URL in the " +
"cid scheme");
}
try {
contentID = URLDecoder.decode(value.substring(4), "ascii");
} catch (UnsupportedEncodingException ex) {
// We should never get here
throw new XMLStreamException(ex);
}
} else {
throw new XMLStreamException("Expected xop:Include element information item with " +
"a (single) href attribute");
}
}
public void writeEndElement() throws XMLStreamException {
if (inXOPInclude) {
if (contentID == null) {
throw new XMLStreamException("Encountered an xop:Include element without " +
"href attribute");
}
// TODO: we should create a DataHandlerProvider if isLoaded returns false for the given contentID
DataHandler dh;
try {
dh = mimePartProvider.getDataHandler(contentID);
} catch (IOException ex) {
throw new XMLStreamException("Error while fetching data handler", ex);
}
try {
dataHandlerWriter.writeDataHandler(dh, contentID, true);
} catch (IOException ex) {
throw new XMLStreamException("Error while writing data handler", ex);
}
inXOPInclude = false;
contentID = null;
} else {
super.writeEndElement();
}
}
}