import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

import javax.swing.*;

public class JTextFieldTest extends JFrame implements ActionListener{
	
	private JTextField[] textFields;
	
	private String fileName = "UserData.txt";
		
	public JTextFieldTest(){
		super("JTextFieldTest");
		init();
	}
	
	public static void main(String[] args){
		new JTextFieldTest();
	}
	
	public void init(){
		

		load();
		JPanel textFieldPanel = new JPanel();
		for (int i = 0; i < textFields.length; i++){
			textFieldPanel.add(textFields[i]);
		}


		getContentPane().add(textFieldPanel,BorderLayout.NORTH);

		JPanel buttonPanel = new JPanel();
		buttonPanel.setLayout(new FlowLayout());
		
		JButton saveButton = new JButton("Save");
		saveButton.addActionListener(this);
		buttonPanel.add(saveButton);


		JButton clearButton = new JButton("Clear");
		clearButton.addActionListener(this);
		buttonPanel.add(clearButton);

		JButton exitButton = new JButton("Exit");
		exitButton.addActionListener(this);
		buttonPanel.add(exitButton);

		getContentPane().add(buttonPanel,BorderLayout.CENTER);
		pack();
		setLocationRelativeTo(null);
		show();		
		
	}
	
	public void actionPerformed(ActionEvent ae){
		String actionCommand = ae.getActionCommand();
		if (actionCommand.compareTo("Save") == 0) {
			save();
		}else if (actionCommand.compareTo("Clear") == 0) {
			clear();
		}else if (actionCommand.compareTo("Exit") == 0) {
			exit();
		}
	}
		
	public void save(){
		try{
			FileWriter fw = new FileWriter(fileName);
			for (int i = 0; i < textFields.length; i++){
				fw.write(String.valueOf(i) + " " + textFields[i].getText());
			}
			fw.close();
		}catch(FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());
		}catch(IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());			
		}		
	}
	
	public void load(){
		try{
			Vector strings = new Vector();
			FileReader fr = new FileReader(fileName);
			BufferedReader br = new BufferedReader(fr);
			String lineRead = "";
			while ((lineRead = br.readLine()) != null){
				strings.add(lineRead);
			}
			fr.close();	
			textFields = new JTextField[strings.size()];
			for (int i = 0; i < strings.size(); i++){
				String nextLine = (String) strings.elementAt(i);
				String[] args = nextLine.split(" ");
				int index = toInt(args[0]);
				String value = args[1];
				textFields[index-1] = new JTextField(value);	
			}
		}catch(FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());
		}catch(IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());			
		}
	}
	
	public void clear(){
		for (int i = 0; i < textFields.length; i++){
			textFields[i].setText("");
		}
	}
	
	private int toInt(String s){
		int n = -1;
		try{
			n = Integer.parseInt(s);
		}catch(NumberFormatException nfe){
			n = -1;
			System.err.println("NumberFormatException: " + nfe.getMessage());
		}
		return n;
	}
	
	public void exit(){
		System.exit(0);
	}
}