import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;

import java.io.*;


/**
 * Main.java
 * Clase de practica para el manejo de archivos binarios en Java.
 * 
 * @author Magus
 * @version 1.0
 */
public class Main extends JFrame implements ActionListener {

    private JButton btnAbrir;
    private JButton btnGuardar;
    private JCheckBox chkCasado;
    private JLabel lblEdad;
    private JLabel lblFileName;
    private JLabel lblLine;
    private JLabel lblNombre;
    private JLabel lblPeso;
    private JTextField txtEdad;
    private JTextField txtFileName;
    private JTextField txtNombre;
    private JTextField txtPeso;
    
    public Main() {
        
        GridBagConstraints gridBagConstraints;

        lblNombre = new JLabel();
        txtNombre = new JTextField();
        lblEdad = new JLabel();
        txtEdad = new JTextField();
        chkCasado = new JCheckBox();
        lblPeso = new JLabel();
        txtPeso = new JTextField();
        lblFileName = new JLabel();
        txtFileName = new JTextField();
        lblLine = new JLabel();
        btnAbrir = new JButton();
        btnGuardar = new JButton();

        getContentPane().setLayout(new GridBagLayout());

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        lblNombre.setLabelFor(txtNombre);
        lblNombre.setText("Nombre");
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(lblNombre, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.gridwidth = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 3.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(txtNombre, gridBagConstraints);

        lblEdad.setText("Edad");
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(lblEdad, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.gridwidth = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 3.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(txtEdad, gridBagConstraints);

        chkCasado.setText("\u00bfCasado?");
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 5;
        gridBagConstraints.gridwidth = 4;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(chkCasado, gridBagConstraints);

        lblPeso.setText("Peso");
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(lblPeso, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.gridwidth = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 3.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(txtPeso, gridBagConstraints);

        lblFileName.setLabelFor(txtNombre);
        lblFileName.setText("Nombre de Archivo");
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(lblFileName, gridBagConstraints);

        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 3;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 3.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(txtFileName, gridBagConstraints);

        lblLine.setBackground(new Color(255, 0, 0));
        lblLine.setFocusable(false);
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.gridwidth = 4;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 0.5;
        getContentPane().add(lblLine, gridBagConstraints);

        btnAbrir.setText("Abrir");
        btnAbrir.addActionListener(this);
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridy = 6;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(btnAbrir, gridBagConstraints);

        btnGuardar.setText("Guardar");
        btnGuardar.addActionListener(this);
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridy = 6;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.weighty = 1.0;
        getContentPane().add(btnGuardar, gridBagConstraints);
        
        setSize(300,500);
        setVisible(true);
        setTitle("Manejo de Archivos");
    }

        /**
        * @param args argumentos de la lina de comandos
        */
        public static void main(String[] args) {
            Main app = new Main();
        }

        /**
         * Metodo que responde a eventos, se va a encargar de manejar los archivos.
         * En caso de que el boton presionado fuera el boton de abrir abre el archivo
         * que se ha puesto en la linea de archivo, en caso de que el boton presionado
         * fuera el de guardar guarda los datos de la forma al archivo en la linea
         * de nombre de archivo.
         * 
         * @param e Evento que sucedio.
         */
        public void actionPerformed(ActionEvent e) {
            String fileName = txtFileName.getText();
            if (e.getSource() == btnAbrir) {
                try {
                    /** 
                     * Primero tengo que crear un objeto de tipo DataInputStream 
                     * para poder abir archivos, despues tengo que ir leyendo 
                     * todos los datos mediatne los metodos para leer de 
                     * archivos binarios e irlos copiando a los controles.
                     */
                    DataInputStream fileIn = new DataInputStream(new FileInputStream(fileName));
                    String nombre = fileIn.readUTF();
                    int edad = fileIn.readInt();
                    double peso = fileIn.readDouble();
                    boolean isCasado = fileIn.readBoolean();
                    
                    txtNombre.setText(nombre);
                    txtEdad.setText(String.valueOf(edad));
                    txtPeso.setText(String.valueOf(peso));
                    chkCasado.setSelected(isCasado);
                } catch (FileNotFoundException fnfe) {
                    JOptionPane.showMessageDialog(null, "No encuentro el archivo!", "Error", JOptionPane.ERROR_MESSAGE);
                } catch (IOException ioe) {
                    JOptionPane.showMessageDialog(null, "No puedo leer el archivo!", "Error", JOptionPane.ERROR_MESSAGE);
                }
                
            } else if (e.getSource() == btnGuardar) {
                try {
                    DataOutputStream fileOut = new DataOutputStream(new FileOutputStream(fileName));
                    
                    fileOut.writeUTF(txtNombre.getText());
                    fileOut.writeInt( Integer.parseInt(txtEdad.getText()) );
                    fileOut.writeDouble( Double.parseDouble(txtPeso.getText()) );
                    fileOut.writeBoolean(chkCasado.isSelected());
                } catch (FileNotFoundException fnfe) {
                    JOptionPane.showMessageDialog(null, "No encuentro el archivo!", "Error", JOptionPane.ERROR_MESSAGE);
                } catch (IOException ioe) {
                    JOptionPane.showMessageDialog(null, "No puedo leer el archivo!", "Error", JOptionPane.ERROR_MESSAGE);
                }
            }
    }
}