/*
* 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.vinci.transport.document;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.apache.vinci.debug.Debug;
import org.apache.vinci.transport.FrameComponent;
import org.apache.vinci.transport.FrameLeaf;
import org.apache.vinci.transport.ServiceException;
import org.apache.vinci.transport.TransportConstants;
import org.apache.vinci.transport.Transportable;
import org.apache.vinci.transport.VinciFrame;
import org.apache.vinci.transport.util.TransportableConverter;
/**
* Class for parsing an XML document and representing it using any of the various jVinci-compatible
* document models.
*
*/
public class XMLToVinci {
/**
* Utility class not intended to be instantiated.
*/
private XMLToVinci() {
}
private static class StackEntry {
List sub_entries = null;
StackEntry parent = null;
String ename_or_pcdata;
FrameComponent component = null;
}
private static class AStackEntry extends StackEntry {
org.apache.vinci.transport.Attributes attributes = null;
}
/**
* This is a SAX document handler to parse XML into VinciFrames.
*/
private static class VinciFrameHandler extends DefaultHandler {
protected StackEntry top = null;
public void startElement(String uri, String name, String qName, org.xml.sax.Attributes atts) {
StackEntry entry = new StackEntry();
entry.ename_or_pcdata = qName;
entry.sub_entries = new ArrayList(2);
if (top == null) {
top = entry;
} else {
top.sub_entries.add(entry);
entry.parent = top;
top = entry;
}
}
/**
* @pre top != null
* @pre top.sub_entries != null
*/
public void endElement(String uri, String name, String qName) {
// Debug.p("End element: " + qName);
if (top.sub_entries.size() == 0) {
// Debug.p("Empty element.");
top.component = new VinciFrame();
} else {
StackEntry child = (StackEntry) top.sub_entries.get(0);
// Debug.p("Frameleaf.");
if (top.sub_entries.size() == 1 && child.sub_entries == null) {
// This is a frameleaf
top.component = new FrameLeaf(child.ename_or_pcdata);
} else {
VinciFrame c = new VinciFrame();
top.component = c;
for (int i = 0; i < top.sub_entries.size(); i++) {
child = (StackEntry) top.sub_entries.get(i);
if (child.component != null) {
c.add(child.ename_or_pcdata, child.component);
} else {
c.fadd(TransportConstants.PCDATA_KEY, child.ename_or_pcdata);
}
child.sub_entries = null;
}
}
}
// top.sub_entries = null;
if (top.parent != null) {
top = top.parent;
}
}
/**
* @pre ch != null
* @pre start < ch.length
* @pre length >= start
* @pre top != null
* @pre top.sub_entries != null
*/
public void characters(char[] ch, int start, int length) {
if (top.sub_entries.size() != 0) {
StackEntry entry = (StackEntry) top.sub_entries.get(top.sub_entries.size() - 1);
if (entry.sub_entries == null) {
entry.ename_or_pcdata += new String(ch, start, length);
// Debug.p("pcdata1: " + entry.ename_or_pcdata);
return;
}
}
StackEntry entry = new StackEntry();
top.sub_entries.add(entry);
entry.ename_or_pcdata = new String(ch, start, length);
}
}
/**
* This is a SAX document handler to parse XML into AFrames.
*/
private static class AFrameHandler extends VinciFrameHandler {
AFrameHandler() {
}
public void startElement(String uri, String name, String qName, org.xml.sax.Attributes a) {
// Debug.p("Attributes: " + qName + " : " + atts.getLength());
AStackEntry entry = new AStackEntry();
entry.ename_or_pcdata = qName;
if (a.getLength() > 0) {
org.apache.vinci.transport.Attributes frame_attributes = new org.apache.vinci.transport.Attributes();
for (int i = 0; i < a.getLength(); i++) {
// Debug.p("Att: " + a.getQName(i) + " : " + a.getValue(i));
frame_attributes.fadd(a.getQName(i), a.getValue(i));
}
entry.attributes = frame_attributes;
}
entry.sub_entries = new ArrayList(2);
if (top == null) {
top = entry;
} else {
top.sub_entries.add(entry);
entry.parent = top;
top = entry;
}
}
public void endElement(String uri, String name, String qName) {
if (top.sub_entries.size() == 0) {
AFrame c = new AFrame();
top.component = c;
} else {
StackEntry child = (StackEntry) top.sub_entries.get(0);
if (top.sub_entries.size() == 1 && child.sub_entries == null) {
AFrameLeaf l = new AFrameLeaf(child.ename_or_pcdata);
top.component = l;
} else {
AFrame c = new AFrame();
top.component = c;
for (int i = 0; i < top.sub_entries.size(); i++) {
child = (StackEntry) top.sub_entries.get(i);
if (child.component != null) {
c.add(child.ename_or_pcdata, child.component);
} else {
c.fadd(TransportConstants.PCDATA_KEY, child.ename_or_pcdata);
}
child.sub_entries = null;
}
}
}
org.apache.vinci.transport.Attributes a = ((AStackEntry) top).attributes;
if (a != null) {
top.component.setAttributes(a);
}
if (top.parent != null) {
top = top.parent;
}
}
}
/**
* Populate the empty document with the XML yielded by the provided reader.
*
* @param empty
* An empty document to be populated.
* @param r
* A reader providing the XML to populate the empty document.
* @exception ServiceException
* if there is a parse error.
*/
public static Transportable xmlToTransportable(Reader r, Transportable empty)
throws ServiceException {
TransportableConverter.convert(xmlToAFrame(r), empty);
return empty;
}
/**
* Convert the XML document (provided as a Reader) to a VinciFrame document model. Throws
* ServiceException if the XML parser reports any error. WARNING: This method will silently ignore
* any attributes or processing instructions within the document since VinciFrame cannot represent
* them. Consider using AFrame if attribute support is required.
*
* This implementation of xmlToVinciFrame uses apache SAX parser directly. It should be faster,
* and it should be tolerant of undeclared namespaces, unlike the previous impl.
*
* @param r
* A reader providing the XML to convert.
* @exception ServiceException
* if there is a parse error.
*/
public static VinciFrame xmlToVinciFrame(Reader r) throws ServiceException {
XMLReader xr;
try {
xr = SAXParserFactory.newInstance().newSAXParser().getXMLReader();
} catch (SAXException e) {
throw new ServiceException("Error creating SAX Parser: " + e);
} catch (ParserConfigurationException e) {
throw new ServiceException("Error creating SAX Parser: " + e);
}
// prevent undeclared namespace warnings.
try {
xr.setFeature("http://xml.org/sax/features/namespaces", false);
VinciFrameHandler handler = new VinciFrameHandler();
xr.setContentHandler(handler);
xr.setErrorHandler(handler);
xr.parse(new InputSource(r));
return (VinciFrame) handler.top.component;
} catch (IOException e) {
Debug.reportException(e);
throw new ServiceException("Reader IO error: " + e);
} catch (SAXException e) {
Debug.reportException(e);
throw new ServiceException("XML Parse error: " + e);
}
}
/**
* Convert the XML document (provided as a Reader) to the AFrame document model. Throws
* ServiceException if the XML parser reports any error. WARNING: This method will silently ignore
* any processing instructions within the document since AFrame cannot represent them.
*
* @param r
* A reader providing the XML to convert.
* @exception ServiceException
* if there is a parse error.
*/
/*
* public static AFrame xmlToAFrame(Reader r) throws ServiceException { return (AFrame)
* xmlToTransportable(r, new AFrame()); }
*/
public static AFrame xmlToAFrame(Reader r) throws ServiceException {
XMLReader xr;
try {
xr = SAXParserFactory.newInstance().newSAXParser().getXMLReader();
} catch (SAXException e) {
throw new ServiceException("Error creating SAX Parser: " + e);
} catch (ParserConfigurationException e) {
throw new ServiceException("Error creating SAX Parser: " + e);
}
// prevent undeclared namespace warnings.
try {
xr.setFeature("http://xml.org/sax/features/namespaces", false);
AFrameHandler handler = new AFrameHandler();
xr.setContentHandler(handler);
xr.setErrorHandler(handler);
xr.parse(new InputSource(r));
return (AFrame) handler.top.component;
} catch (IOException e) {
Debug.reportException(e);
throw new ServiceException("Reader IO error: " + e);
} catch (SAXException e) {
Debug.reportException(e);
throw new ServiceException("XML Parse error: " + e);
}
}
}