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I need help with Currency Converter code reading from XML file.

Can anybody help me with this project. I am trying to let this program read from XML file. Data online on this web: http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml. How to make this project pull the information from that web and put it txt file then appear it on the GUI. This what I have done and I still have error.
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * Converter.java
 *
 * Created on Dec 1, 2011, 8:06:24 PM
 */
package Converter;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JComboBox;
import javax.swing.JFormattedTextField;



/**
 *
 * @author Abdullah
 */
public class Converter extends javax.swing.JFrame {

    /** Creates new form Converter */
     String currentPattern;
    private HashMap<String, Double> HashMap1;
    private ArrayList<String> List;
    
    
    

    
    
    
    
    
    
       private ArrayList<String> currencies;;
    private Converter cc;
DecimalFormat df = new DecimalFormat("#####.00");

    /** Creates new form Converter */
    
public Converter() throws Exception{
    initComponents();

HashMap1= new HashMap<String, Double>();
List = new ArrayList<String>();
try{
 URL ecb = new url.("http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml");
BufferedReader in = new BufferedReader(new InputStreamReader(ecb.openStream()));
FileWriter fw = new FileWriter("Rates.xml");
String inputLine;


while ((inputLine = in.readLine()) != null){
System.out.println(inputLine);
fw.write(inputLine);
}

in.close();
fw.close();
}
catch(Exception e){
System.exit(1);
}


        




        /** Creates new form CurrencyConverterGUI */

     //   initComponents();
        String[] patternExamples = {"EUR", "USD"};


        HashMap1 = new HashMap<String, Double>();
        List = new ArrayList<String>();
        currencies = new ArrayList<String>();

        populateHashMap();
        
         CurrencyBox1.removeAll();
         CurrencyBox2.removeAll();
         for(String s: currencies){
              CurrencyBox1.addItem(s);  
                CurrencyBox2.addItem(s); 
         }
               CurrencyBox1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyBox1ActionPerformed(evt);
            }
        });

              CurrencyBox2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyBox2ActionPerformed(evt);
            }
        });

        /*
        currentPattern = patternExamples[0];

       for(int j=0; j<patternExamples.length; j++){
        CurrencyBox1.addItem(patternExamples[j]);
          CurrencyBox2.addItem(patternExamples[j]);}
        */
        CurrencyBox1.setEditable(false);
             CurrencyBox2.setEditable(false);

        //CurrencyBox1.addActionListener(this);
    }

    private void populateHashMap() {
        Scanner SC = null;
        try {

            SC = new Scanner(new FileReader(new File("Rates.txt")));
        } catch (IOException e) {
            System.err.println("File Error when reading rates.txt file");
            //return;
            System.exit(1);
        }
        while (SC.hasNextLine()) {
            String[] S = SC.nextLine().split(" ");
            currencies.add(S[0]);
            HashMap1.put(S[0], Double.valueOf(S[1]));




        }
    }
public Object[] getCurrencies() {
		return List.toArray();
	}

	public double convert(String FC, String TC, double amt) {

	double result = amt / HashMap1.get(FC) * HashMap1.get(TC);
		return result;
                 }
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
       
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        CurrencyBox1 = new javax.swing.JComboBox();
        CurrencyBox2 = new javax.swing.JComboBox();
        CurrencyText1 = new javax.swing.JTextField();
        CurrencyText2 = new javax.swing.JTextField();
        ResetButton = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        CurrencyBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "EUR" }));
        CurrencyBox1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyBox1ActionPerformed(evt);
            }
        });

        CurrencyBox2.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "USD" }));
        CurrencyBox2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyBox2ActionPerformed(evt);
            }
        });

        CurrencyText1.setText("0.0");
        CurrencyText1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyText1ActionPerformed(evt);
            }
        });

        CurrencyText2.setText("0.0");
        CurrencyText2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                CurrencyText2ActionPerformed(evt);
            }
        });

        ResetButton.setText("Reset");
        ResetButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                ResetButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addComponent(CurrencyText1)
                            .addComponent(CurrencyBox1, 0, 125, Short.MAX_VALUE))
                        .addGap(126, 126, 126)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addComponent(CurrencyText2)
                            .addComponent(CurrencyBox2, 0, 97, Short.MAX_VALUE)))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(145, 145, 145)
                        .addComponent(ResetButton)))
                .addContainerGap(59, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(67, 67, 67)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(CurrencyBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(CurrencyBox2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(36, 36, 36)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(CurrencyText1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(CurrencyText2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(63, 63, 63)
                .addComponent(ResetButton)
                .addContainerGap(71, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>

    private void CurrencyBox1ActionPerformed(java.awt.event.ActionEvent evt) {                                             
       
      //  CurrencyText1 = new JFormattedTextField(NumberFormat.getInstance());
       //CurrencyConverter currconv = new CurrencyConverter();

     //   JComboBox cb = (JComboBox) evt.getSource();
        //String from = (String) cb.getSelectedItem();
          String from = (String) CurrencyBox2.getSelectedItem();
        String to =(String)  CurrencyBox1.getSelectedItem();
        //double amount = Double.parseDouble(this.CurrencyText1.getText());
          String s=  this.CurrencyText2.getText();
                 if(s.trim().length() == 0){

//pop up errort message - input is empty
                       return;

                          }

  double amount = Double.parseDouble(s);

       double converted = convert(from, to, amount);

            CurrencyText1.setText(df.format(converted) + "");
            // double result = cc.convert(from, to, amount);
		//CurrencyBox1.setSelectedItem(new Double(result));


    }                                            

    private void CurrencyBox2ActionPerformed(java.awt.event.ActionEvent evt) {                                             
        // JComboBox cb = (JComboBox) evt.getSource();
       // CurrencyConverter currconv = new CurrencyConverter();
        //String from = (String) cb.getSelectedItem();
         String from = (String) CurrencyBox1.getSelectedItem();
        String to = (String) CurrencyBox2.getSelectedItem();
         String s=  CurrencyText1.getText();
               if(s.trim().length() == 0){

//pop up errort message - input is empty
                        return;

                         }

           // double amount = Double.parseDouble(this.CurrencyText1.getText());

             double amount = Double.parseDouble(s);

             System.out.println("from " + from + " to " + to + " amount " + amount);

            double converted = convert(from, to, amount);

            CurrencyText2.setText(df.format(converted) + "");

        //double amount = Double.parseDouble(this.CurrencyText2.getText());
              //  double result = cc.convert(from, to, amount);
		//CurrencyBox2.setSelectedItem(new Double(result));
    }                                            

    private void CurrencyText1ActionPerformed(java.awt.event.ActionEvent evt) {                                              
        // TODO add your handling code here:
    }                                             

    private void CurrencyText2ActionPerformed(java.awt.event.ActionEvent evt) {                                              
        // TODO add your handling code here:
    }                                             

    private void ResetButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        CurrencyText1.setText("");

        CurrencyText2.setText("");
    }                                           

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Converter.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Converter.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Converter.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Converter.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                try {
                    new Converter().setVisible(true);
                } catch (Exception ex) {
                    Logger.getLogger(Converter.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JComboBox CurrencyBox1;
    private javax.swing.JComboBox CurrencyBox2;
    private javax.swing.JTextField CurrencyText1;
    private javax.swing.JTextField CurrencyText2;
    private javax.swing.JButton ResetButton;
    // End of variables declaration
}
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CEHJ
Something is null at line 166 of Currency.java