Cut.java

package org.softlang.company.features;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class Cut extends DefaultHandler {

    private static String ns = "http://www.company.softlang.org/company.xsd";
    private static XMLOutputFactory factory = XMLOutputFactory.newInstance();
    private XMLStreamWriter writer;
    private boolean isSalary = false;
    private String lastNamespace = null;

    public Cut(String file)
         throws FileNotFoundException, XMLStreamException {
           writer = factory.createXMLStreamWriter(new FileOutputStream(file));
    }

    @Override
    public void startDocument() throws SAXException {
        try {
            writer.writeStartDocument();
        } catch (XMLStreamException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void endDocument() throws SAXException {
        try {
            writer.writeEndDocument();
            writer.close();
        } catch (XMLStreamException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void startElement(String uri, String name, String qName,
            Attributes atts) {

        try {
            isSalary = (uri.equals(ns) && name.equals("salary"));
            writer.writeStartElement(name);
            if (!(uri.equals(lastNamespace))) {
                lastNamespace = uri;
                writer.setDefaultNamespace(uri);
                writer.writeDefaultNamespace(uri);
            }
            for (int i = 0; i < atts.getLength(); i++) {
                writer.writeAttribute(atts.getLocalName(i), atts.getValue(i));
            }
        } catch (XMLStreamException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void endElement(String uri, String name, String qName) {
        isSalary = false;
        try {
            writer.writeEndElement();
        } catch (XMLStreamException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) {
        try {
            if (isSalary) {
                String str = String.valueOf(ch, start, length);
                double salary = Double.parseDouble(str);
                writer.writeCharacters(String.valueOf(salary / 2));
            } else {
                writer.writeCharacters(String.valueOf(ch, start, length));
            }
        } catch (XMLStreamException e) {
            e.printStackTrace();
        }
    }

}