XML Parser

Parser.java

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package org.me.chat;

import java.io.IOException;
import java.util.ArrayList;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 *
 * @author Lahiru
 */
public class Parser {
    private static ArrayList<User> userArrayList = new ArrayList<>();
    private static String file = "E:\\ChatWebApp\\ChatWebApp\\users.xml";

    public static void setFile(String file) {
        Parser.file = file;
    }

    public static String parseFile() {
        //TODO write your implementation code here:
        userArrayList.clear();
        String r="ads" ;
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(file);
            NodeList userList = doc.getElementsByTagName("user");
            String u = "";
            String p = "";
            for (int i = 0; i < userList.getLength(); i++) {
                Node userItem = userList.item(i);
                if (userItem.getNodeType() == Node.ELEMENT_NODE) {
                    Element userElement = (Element) userItem;
                    //name part
                    NodeList nameList = userElement.getElementsByTagName("name");
                    Node nameItem = nameList.item(0);
                    if (nameItem.getNodeType() == Node.ELEMENT_NODE) {
                        Element nameElement = (Element) nameItem;
                        u = nameElement.getTextContent();
                    }
                    //pass part
                    NodeList passList = userElement.getElementsByTagName("pass");
                    Node passItem = passList.item(0);
                    if (nameItem.getNodeType() == Node.ELEMENT_NODE) {
                        Element passElement = (Element) passItem;

                        p = passElement.getTextContent();
                    }
                    //User usr = ;
                    r = i  + u + p;
                    userArrayList.add(new User(u, p));
                    
                    //System.out.println(r);
                }
            }
        } catch (ParserConfigurationException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        } catch (SAXException ex) {
            ex.printStackTrace();
        }
        
        return r;

    }

    public static boolean validateUser(String name, String pass) {
        boolean login = false;
        parseFile();
        for (User value : userArrayList) {
            if (value.getUsername().equals(name)) {
                login = value.getPassword().equals(pass);
            }
        }
        return login;
    }

    public static boolean writeFile(String username, String password) {
        boolean saved = false;
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();

            // root element
            Document doc = builder.parse(file);
            Element root = doc.getDocumentElement();

            // user elements
            Element user = doc.createElement("user");
            root.appendChild(user);

            //name elements
            Element name = doc.createElement("name");
            name.appendChild(doc.createTextNode(username));
            user.appendChild(name);

            //pass elements
            Element pass = doc.createElement("pass");
            pass.appendChild(doc.createTextNode(password));
            user.appendChild(pass);

            // write the content into xml file
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(file);

            transformer.transform(source, result);

            saved = true;

        } catch (IOException ex) {
            ex.printStackTrace();
        } catch (SAXException ex) {
            ex.printStackTrace();
        } catch (ParserConfigurationException pce) {
            pce.printStackTrace();
        } catch (TransformerException tfe) {
            tfe.printStackTrace();
        }
        return saved;
    }
}