import org.jdom.*;
import org.jdom.input.SAXBuilder;
import org.jdom.xpath.XPath;

import java.io.IOException;
import java.util.List;

public class bars {


	public void toon(){
        SAXBuilder parser = new SAXBuilder();
        Document document = null;
        try {
            /*OEFENING 1
            document = parser.build("./bars.xml");
            XPath xPath = XPath.newInstance("//y-axis-title"); oef 1.1
            XPath xPath = XPath.newInstance("//bars/bar[@number = 4]");
            XPath xPath = XPath.newInstance("//bar[@number = 5]");
            */

        	/*OEFENING 2
            document = parser.build("./moreover.xml");
            XPath xPath = XPath.newInstance("//article[@code = 13549014]/harvest_time");
            */

            document = parser.build("./informationgain.xml");

            /*  OEFENING 3
            XPath xPath = XPath.newInstance("//n-gram[@frequency < 10]");
            XPath xPath = XPath.newInstance("//n-gram[@frequency < 10 and @gain > 0.5]");
            XPath xPath = XPath.newInstance("//n-gram[contains(.,'=') ]")
            XPath xPath = XPath.newInstance("//n-gram[string-length()>10 ]");*/
            XPath xPath = XPath.newInstance("//n-gram[substring(.,1,2)='de' ]");
            List<Element> elements = xPath.selectNodes(document);

            System.out.println(elements.size());
            for(Element element : elements){
                System.out.println(element.getValue());
            }
        } catch (JDOMException e) {
            System.out.println("");
        } catch (IOException e) { }
            System.out.println("");
    }


}