package org.polyglotted.xpathstax;
import static com.google.common.base.Preconditions.checkNotNull;
import static org.polyglotted.xpathstax.model.XPathRequest.SLASH;
import java.io.InputStream;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import javax.xml.stream.events.XMLEvent;
import org.codehaus.stax2.XMLInputFactory2;
import org.codehaus.stax2.XMLStreamReader2;
import org.polyglotted.xpathstax.api.NodeHandler;
import org.polyglotted.xpathstax.bind.NodeConverter;
import org.polyglotted.xpathstax.model.XPathRequest;
import org.polyglotted.xpathstax.model.XmlAttribute;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.io.Closeables;
public class XPathStaxParser {
private static final XMLInputFactory2 factory = createFactory();
private final Map<XPathRequest, NodeHandler> handlersMap = Maps.newConcurrentMap();
public void addHandler(XPathRequest request, NodeHandler handler) {
handlersMap.put(checkNotNull(request), checkNotNull(handler));
}
public <T> void addHandler(NodeConverter<T> converter) {
addHandler(converter.getRequest(), converter);
}
public void parse(InputStream inputStream) {
final NodeContext context = new NodeContext();
try {
XMLStreamReader2 xmlr = (XMLStreamReader2) factory.createXMLStreamReader(inputStream);
String curElement = "";
int eventType = xmlr.getEventType();
while (xmlr.hasNext()) {
eventType = xmlr.next();
switch (eventType) {
case XMLEvent.START_ELEMENT:
curElement = curElement + SLASH + getName(xmlr);
processStartElement(xmlr, context, curElement);
break;
case XMLEvent.CHARACTERS:
context.updateText(curElement,
new String(xmlr.getTextCharacters(), xmlr.getTextStart(), xmlr.getTextLength()));
break;
case XMLEvent.END_ELEMENT:
processEndElement(xmlr, context, curElement);
curElement = curElement.substring(0, curElement.lastIndexOf(SLASH + getName(xmlr)));
break;
}
}
} catch (Exception ex) {
throw new RuntimeException("parse failed", ex);
} finally {
Closeables.closeQuietly(inputStream);
}
}
private void processStartElement(XMLStreamReader2 xmlr, NodeContext context, String curElement) {
XmlAttribute attribute = XmlAttribute.from(xmlr);
List<NodeHandler> handlers = Lists.newArrayList();
for (Entry<XPathRequest, NodeHandler> entry : handlersMap.entrySet()) {
if (entry.getKey().canProcess(curElement, attribute, context)) {
NodeHandler handler = entry.getValue();
handler.elementStart(getName(xmlr));
handlers.add(handler);
}
}
context.addHandlers(curElement, attribute, handlers);
}
private void processEndElement(XMLStreamReader2 xmlr, NodeContext context, String curElement) {
if (!SLASH.equals(curElement)) {
context.sendUpdates(curElement);
}
}
private static String getName(XMLStreamReader2 xmlr) {
return xmlr.getName().toString();
}
private static XMLInputFactory2 createFactory() {
XMLInputFactory2 xmlif = (XMLInputFactory2) XMLInputFactory2.newInstance();
xmlif.configureForConvenience();
return xmlif;
}
}