package org.maltparserx.core.propagation.spec;
import java.io.IOException;
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.maltparserx.core.exception.MaltChainedException;
import org.maltparserx.core.propagation.PropagationException;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
* @author Johan Hall
*
*/
public class PropagationSpecsReader {
public PropagationSpecsReader() { }
public void load(URL url, PropagationSpecs propagationSpecs) throws MaltChainedException {
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Element root = null;
root = db.parse(url.openStream()).getDocumentElement();
if (root == null) {
throw new PropagationException("The propagation specification file '"+url.getFile()+"' cannot be found. ");
}
readPropagationSpecs(root, propagationSpecs);
} catch (IOException e) {
throw new PropagationException("The propagation specification file '"+url.getFile()+"' cannot be found. ", e);
} catch (ParserConfigurationException e) {
throw new PropagationException("Problem parsing the file "+url.getFile()+". ", e);
} catch (SAXException e) {
throw new PropagationException("Problem parsing the file "+url.getFile()+". ", e);
}
}
private void readPropagationSpecs(Element propagations, PropagationSpecs propagationSpecs) throws MaltChainedException {
NodeList propagationList = propagations.getElementsByTagName("propagation");
for (int i = 0; i < propagationList.getLength(); i++) {
readPropagationSpec((Element)propagationList.item(i), propagationSpecs);
}
}
private void readPropagationSpec(Element propagation, PropagationSpecs propagationSpecs) throws MaltChainedException {
int nFrom = propagation.getElementsByTagName("from").getLength();
if (nFrom < 1 && nFrom > 1) {
throw new PropagationException("Propagation specification wrongly formatted: Number of 'from' elements is '"+nFrom+"', must be 1.");
}
int nTo = propagation.getElementsByTagName("to").getLength();
if (nTo < 1 && nTo > 1) {
throw new PropagationException("Propagation specification wrongly formatted: Number of 'to' elements is '"+nTo+"', must be 1.");
}
int nFor = propagation.getElementsByTagName("for").getLength();
if (nFor > 1) {
throw new PropagationException("Propagation specification wrongly formatted: Number of 'for' elements is '"+nFor+"', at most 1.");
}
int nOver = propagation.getElementsByTagName("over").getLength();
if (nOver > 1) {
throw new PropagationException("Propagation specification wrongly formatted: Number of 'over' elements is '"+nOver+"',at most 1.");
}
String fromText = ((Element)propagation.getElementsByTagName("from").item(0)).getTextContent().trim();
if (fromText.length() == 0) {
throw new PropagationException("Propagation specification wrongly formatted: The 'from' element is empty");
}
String toText = ((Element)propagation.getElementsByTagName("to").item(0)).getTextContent().trim();
if (toText.length() == 0) {
throw new PropagationException("Propagation specification wrongly formatted: The 'to' element is empty");
}
String forText = "";
if (nFor != 0) {
forText = ((Element)propagation.getElementsByTagName("for").item(0)).getTextContent().trim();
}
String overText = "";
if (nOver != 0) {
overText = ((Element)propagation.getElementsByTagName("over").item(0)).getTextContent().trim();
}
propagationSpecs.add(new PropagationSpec(fromText, toText, forText, overText));
}
}