Zad1.java

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

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

import java.util.HashMap;
import java.util.Map;

public class Zad1 {

    //private static final String FILE = "C:\\Documents and Settings\\Administrator\\Pulpit\\mkyong.xml";
    private static final String FILE = "C:\\Documents and Settings\\Administrator\\Pulpit\\sredniowiecze.xml";

    public static void main(String argv[]) {
        try {
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser saxParser = factory.newSAXParser();
            Zad1Handler handler = new Zad1Handler();
            saxParser.parse(FILE, handler);
            System.out.println(handler.statystyki());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static class Zad1Handler extends DefaultHandler {

        private int zagniezdzenie = 0;
        private int maxZagniezdzenie = 0;
        private Map<String, Integer> wystapienia = new HashMap<>();
        private Map<Integer, Integer> elementówNaPoziomie = new HashMap<>();
        private int maxDlugoscTekstu = 0;
        private int minDlugoscTekstu = 0;
        private int maxAtrybutow = 0;
        private int minAtrybutow = 0;

        public void startElement(String uri, String localName, String qName,
                                 Attributes attributes) throws SAXException {
            zagniezdzenie++;
            maxZagniezdzenie = Math.max(zagniezdzenie, maxZagniezdzenie);
            maxAtrybutow = Math.max(maxAtrybutow, attributes.getLength());
            minAtrybutow = Math.min(minAtrybutow, attributes.getLength());
            increaseStatistic(wystapienia, qName);
            increaseStatistic(elementówNaPoziomie, zagniezdzenie);
            printTabs();
            System.out.println(qName);
        }

        private <T> void increaseStatistic(Map<T, Integer> map, T key) {
            if (map.containsKey(key)) {
                map.put(key, map.get(key) + 1);
            } else {
                map.put(key, 1);
            }
        }

        public void endElement(String uri, String localName,
                               String qName) throws SAXException {
            zagniezdzenie--;
        }

        private void printTabs() {
            for (int i = 0; i < zagniezdzenie; ++i) {
                System.out.print("    ");
            }
        }

        public void characters(char ch[], int start, int length) throws SAXException {
            minDlugoscTekstu = Math.min(minDlugoscTekstu, length);
            maxDlugoscTekstu = Math.max(maxDlugoscTekstu, length);
        }

        public Map<String, String> statystyki() {
            Map<String, String> map = new HashMap<>();
            map.put("Głębokość", Integer.toString(maxZagniezdzenie));
            map.put("Wystąpienia", wystapienia.toString());
            map.put("Elementow na poziomie", elementówNaPoziomie.toString());
            map.put("Maks dlugosc tesktu", Integer.toString(maxDlugoscTekstu));
            map.put("Min dlugosc tesktu", Integer.toString(minDlugoscTekstu));
            map.put("Max atrybutow", Integer.toString(maxAtrybutow));
            map.put("Min atrybutow", Integer.toString(minAtrybutow));

            return map;
        }
    }
}

Zad2.java

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.ParserConfigurationException;

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

import java.io.File;
import java.io.IOException;

public class Zad2 {
    private static final String FILE = "C:\\Documents and Settings\\Administrator\\Pulpit\\mkyong.xml";
    //private static final String FILE = "C:\\Documents and Settings\\Administrator\\Pulpit\\sredniowiecze.xml";

    public static void main(String argv[]) {
        try {
            Document doc = readDocument(FILE);
            Element documentElement = doc.getDocumentElement();
            printNode(documentElement, 0);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void printNode(Node n, int zagniezdzenie) {
        tab(zagniezdzenie);
        System.out.printf("<%s>%n", n.getNodeName());
        NodeList childNodes = n.getChildNodes();
        for (int i = 0; i < childNodes.getLength(); i++) {
            Node node = childNodes.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                printNode(node, zagniezdzenie + 1);
            } else if (node.getNodeType() == Node.TEXT_NODE && !node.getNodeValue().trim().equals("")) {
                tab(zagniezdzenie + 1);
                System.out.printf("'%s'%n", node.getNodeValue().trim());
            }
        }
    }

    private static void tab(int zagniezdzenie) {
        for (int i = 0; i < zagniezdzenie; i++) {
            System.out.print("    ");
        }
    }

    static Document readDocument(String file) throws ParserConfigurationException, SAXException, IOException {
        File fXmlFile = new File(file);
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(fXmlFile);
        doc.getDocumentElement().normalize();
        return doc;
    }
}

Zad22.java

import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class Zad22 {
    private static final String FILE = "C:\\Documents and Settings\\Administrator\\Pulpit\\mkyong.xml";

    public static void main(String argv[]) {
        try {
            Document doc = Zad2.readDocument(FILE);
            Element staff = getFirstChildByTag(doc.getDocumentElement(), "staff");
            dodajWezel(staff, "firstname", doc);
            zmienWezel(staff, "lastname");
            usunWezel(staff, "nickname");

            Zad2.printNode(doc.getDocumentElement(), 0);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void dodajWezel(Element parent, String nazwaWezla, Document doc) {
        Element element = getFirstChildByTag(parent, nazwaWezla);
        Element nowyWezel = doc.createElement("nowyWezel");
        element.appendChild(nowyWezel);
    }

    private static void zmienWezel(Element parent, String nazwaWezla) {
        Element element = getFirstChildByTag(parent, nazwaWezla);
        element.setTextContent("zmieniony wezel");
    }

    private static void usunWezel(Element parent, String nazwaWezla) {
        Element element = getFirstChildByTag(parent, nazwaWezla);
        parent.removeChild(element);
    }

    private static Element getFirstChildByTag(Element documentElement, String tagName) {
        return (Element) documentElement.getElementsByTagName(tagName).item(0);
    }
}