fmbenhassine/XmlMain.java

## company.xml
<?xml version="1.0" encoding="utf-8"?>
<company name="... Applied Physics Laboratory"
         shortName="JHU/APL"
         mission="Enhancing national security ...">
    <head name="Richard Roca" phone="410-778-1234"/>
    <department name="Air and Missile Defense"
                mission="Enhance the operational ...">
        <group name="A1E" numStaff="20"/>
        <group name="A1F" numStaff="15"/>
        <group name="A1G" numStaff="25"/>
    </department>
    <department name="Research and Technology..."
                mission="Assure that ...">
        <group name="RSI" numStaff="15"/>
        <group name="RSS" numStaff="10"/>
    </department>
</company>

## XmlMain.java
package io.github.benas.labs.javase.xml;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.File;
import java.io.IOException;

public class XmlMain {

    public static void main(String[] args) throws ParserConfigurationException, IOException, SAXException {

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

        DocumentBuilder builder = factory.newDocumentBuilder();

        String sourceFile = args[0];

        Document document = builder.parse(new File(sourceFile));

        Element root = document.getDocumentElement();

        System.out.println(root.getTagName());
        System.out.printf(" name: %s%n", root.getAttribute("name"));
        System.out.printf(" short name: %s%n", root.getAttribute("shortName"));
        System.out.printf(" mission: %s%n", root.getAttribute("mission"));

        NodeList departments = root.getElementsByTagName("department");
        for (int i = 0; i < departments.getLength(); i++) {
            Element department = (Element) departments.item(i);
            System.out.println(department.getTagName());
            System.out.printf(" name: %s%n", department.getAttribute("name"));
            System.out.printf(" mission: %s%n", department.getAttribute("mission"));
            System.out.printf(" staff: %s%n", countStaff(department));
        }

    }

    public static int countStaff(Element department) {
        int departmentStaff = 0;
        NodeList groups = department.getElementsByTagName("group");
        for (int i = 0; i < groups.getLength(); i++) {
            Element group = (Element) groups.item(i);
            int groupStaff = Integer.parseInt(group.getAttribute("numStaff"));
            departmentStaff = departmentStaff + groupStaff;
        }
        return (departmentStaff);
    }
}
	<?xml version="1.0" encoding="utf-8"?>
	<company name="... Applied Physics Laboratory"
	shortName="JHU/APL"
	mission="Enhancing national security ...">
	<head name="Richard Roca" phone="410-778-1234"/>
	<department name="Air and Missile Defense"
	mission="Enhance the operational ...">
	<group name="A1E" numStaff="20"/>
	<group name="A1F" numStaff="15"/>
	<group name="A1G" numStaff="25"/>
	</department>
	<department name="Research and Technology..."
	mission="Assure that ...">
	<group name="RSI" numStaff="15"/>
	<group name="RSS" numStaff="10"/>
	</department>
	</company>
	package io.github.benas.labs.javase.xml;

	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;

	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;
	import javax.xml.parsers.ParserConfigurationException;
	import java.io.File;
	import java.io.IOException;

	public class XmlMain {

	public static void main(String[] args) throws ParserConfigurationException, IOException, SAXException {

	DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

	DocumentBuilder builder = factory.newDocumentBuilder();

	String sourceFile = args[0];

	Document document = builder.parse(new File(sourceFile));

	Element root = document.getDocumentElement();

	System.out.println(root.getTagName());
	System.out.printf(" name: %s%n", root.getAttribute("name"));
	System.out.printf(" short name: %s%n", root.getAttribute("shortName"));
	System.out.printf(" mission: %s%n", root.getAttribute("mission"));

	NodeList departments = root.getElementsByTagName("department");
	for (int i = 0; i < departments.getLength(); i++) {
	Element department = (Element) departments.item(i);
	System.out.println(department.getTagName());
	System.out.printf(" name: %s%n", department.getAttribute("name"));
	System.out.printf(" mission: %s%n", department.getAttribute("mission"));
	System.out.printf(" staff: %s%n", countStaff(department));
	}

	}

	public static int countStaff(Element department) {
	int departmentStaff = 0;
	NodeList groups = department.getElementsByTagName("group");
	for (int i = 0; i < groups.getLength(); i++) {
	Element group = (Element) groups.item(i);
	int groupStaff = Integer.parseInt(group.getAttribute("numStaff"));
	departmentStaff = departmentStaff + groupStaff;
	}
	return (departmentStaff);
	}
	}