Saving contents of jinternal frame

Question

Hi, I seem to have a problem saving files from jinternal frames. I created two files, the main GUI which holds the jdesktop pane and the other file (Documento) extends jinternalframe. I want to be able to save the current (active) jinternal frame but I have no idea how to do it. can anyone help me?
import javax.swing.JInternalFrame;
import javax.swing.JDesktopPane;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JMenuBar;
import javax.swing.JFrame;
import javax.swing.KeyStroke;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.Graphics.*;
import javax.swing.JOptionPane;
import java.io.*;
import java.util.*;
*This is the main GUI of the program.
public class mainGUI extends JFrame
                               implements ActionListener,
                                KeyListener{
    JDesktopPane desktop;
    Documento frame;
     private Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
     private JPanel toolbar, editarea, resultarea, blankPanel;
     private JMenu file, edit, project;
     private JMenuItem f_open, f_new, f_save, f_saveas, f_exit, e_select, e_copy, e_paste, p_compile;
     private JTextArea resultfield, editfield,editArea, tstr;
     private JButton bcompile;
     private JFileChooser fc = new JFileChooser();
     private String filepath;
     private ImageIcon bugicon;
     private static int docNum = 0;
     private boolean b_openfile;
     File filename;
    public mainGUI() {
        super("DGJ Program Scanner");
        setSize(800,600);
          setLocation((screen.width-800)/2, (screen.height-600)/2);
        /*Creates the workspace*/
        desktop = new JDesktopPane();
        setContentPane(desktop);
        setJMenuBar(createMenuBar());
        /*Make dragging a little faster*/
        desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
      *This function creates the menu bar
    protected JMenuBar createMenuBar() {
         /*Initializes/instantiates the menu bar and its items*/
          file = new JMenu("File");
          edit = new JMenu("Edit");
          project = new JMenu("Project");
          f_new = new JMenuItem("Create new file");
          f_open = new JMenuItem("Open file...");
          f_save = new JMenuItem("Save current file");
          f_saveas = new JMenuItem("Save As...");
          f_exit = new JMenuItem("Exit program");
          e_select = new JMenuItem("Select All");
          e_copy = new JMenuItem("Copy selected");
          e_paste = new JMenuItem("Paste selected");
          p_compile = new JMenuItem("Scan current file for errors");
          /*Adds listeners to the menu items*/
          f_open.setActionCommand("f_open");
          f_open.addActionListener(this);
          f_save.setActionCommand("f_save");
          f_save.addActionListener(this);
          f_saveas.addActionListener(this);
          f_saveas.setActionCommand("f_saveas");
          f_new.setActionCommand("f_new");
          f_new.addActionListener(this);
          f_exit.setActionCommand("f_exit");
          f_exit.addActionListener(this);
          e_select.setActionCommand("e_select");
          e_select.addActionListener(this);
          e_paste.setActionCommand("e_paste");
          e_paste.addActionListener(this);     
          e_copy.setActionCommand("e_copy");
          e_copy.addActionListener(this);               
          /*Creates the icon of the bug*/
          bugicon = new ImageIcon("images/ladybug.gif");
          /*Creates the menu bar*/
          JMenuBar menu = new JMenuBar();
          menu.add(file);
               file.add(f_new);
               file.add(f_open);
               file.add(f_save);
               file.add(f_saveas);
               file.add(f_exit);
          menu.add(edit);
               edit.add(e_select);
               edit.add(e_copy);
               edit.add(e_paste);
          menu.add(project);
               project.add(p_compile);
          /*Disables the save current file menu...(when program starts, no file is open yet)*/
          f_save.setEnabled(false);
          f_saveas.setEnabled(false);
        return menu;
    //React to menu selections.
    public void actionPerformed(ActionEvent e) {
        if ("f_new".equals(e.getActionCommand()))
        { //new
            createFrame(null);
            f_saveas.setEnabled(true);
        else if("f_open".equals(e.getActionCommand()))
        {//open documento
               fc.setFileFilter(new SpanFilter());
              int retval = fc.showOpenDialog(mainGUI.this);
               tstr = new JTextArea();
               /*This checks if the user has chosen a file*/
            if (retval == JFileChooser.APPROVE_OPTION) {
                filename = fc.getSelectedFile();
                    filepath = filename.getPath();            
                    openFile(filename, new Point(30,30));       
        else if("f_save".equals(e.getActionCommand()))
             try {
                  BufferedWriter out = new BufferedWriter(new FileWriter(filepath));
                  String str;
                  str = editArea.getText();
                  editArea.setText("");  
                  int length = str.length();
                  out.write(str, 0, length);
                  out.close();
                   } catch (Exception ex) {}
                   JInternalFrame fr = new JInternalFrame();
                   fr = desktop.getSelectedFrame();
                   Point p = fr.getLocation();
                    fr.dispose();    
                   openFile(filename, p);
        else if("f_saveas".equals(e.getActionCommand()))
             fc.setFileFilter(new SpanFilter());
              int retval = fc.showSaveDialog(mainGUI.this);
            if (retval == JFileChooser.APPROVE_OPTION) {
                filename = fc.getSelectedFile();
                    filepath = filename.getPath();
                    if(!(filepath.contains(".dgj")))
                         filepath+=".dgj";
                  try {
                       BufferedWriter out = new BufferedWriter(new FileWriter(filepath));
                            String str;
                       str = editArea.getText();
                       int length = str.length();
                       out.write(str, 0, length);
                       out.close();
                   } catch (Exception ex) {}
                   Point p = frame.getLocation();
                    frame.dispose();
               //     editArea.setText("");     
                   openFile(filename, p);
        else if("e_select".equals(e.getActionCommand()))
             editArea.selectAll();
        else if("e_copy".equals(e.getActionCommand()))
               editArea.copy();
        else if("e_paste".equals(e.getActionCommand()))
             editArea.paste();
        else if("f_exit".equals(e.getActionCommand()))
        { //quit
            quit();
    public void openFile(File filename, Point p)
                    /*Reads the file*/
                    try {
                       BufferedReader in = new BufferedReader(new FileReader(filepath));
                         String str;
                         /*empties the textarea*/
                         tstr.setText("");
                         str = in.readLine();
                         /*Copy each line of the file into the temporary textarea*/
                       do{  
                      tstr.append(str);
                      str = in.readLine();
                      /* the "\n" is for the line to appear in the next line in the textarea,
                       * the "\r" is for windows system, wherein "\r" is required for the text
                       * to appear in beginning of the first line*/
                      if(str!=null)
                           tstr.append("\r\n");
                       }while (str != null);
                         /*Opens the new frame*/
                       createFrame(filename, filename.getName(), tstr.getText(), p);
                       in.close();
                   } catch (Exception ex){}
                  b_openfile = true;
                  f_save.setEnabled(true); 
                  f_saveas.setEnabled(true);   
     *Create a new internal frame.
    protected void createFrame(File f) {
         frame = new Documento(f);
     /*     frame = new JInternalFrame("Document "+(++docNum),
              true, //resizable
              true, //closable
              true, //maximizable
              true);
        docNum++;
          frame.setSize(600,400);
          frame.setLocation(20*(docNum%10), 20*(docNum%10));       
         editArea = new JTextArea();
          JScrollPane scroll = new JScrollPane(editArea);     
          editArea.addKeyListener(this);
          editArea.append("");
          frame.add(scroll);
        frame.setVisible(true); //necessary as of 1.3
        desktop.add(frame);
        try {
            frame.setSelected(true);
        } catch (java.beans.PropertyVetoException e) {}
      *Overwrite an existing internal frame for an open file
    protected void createFrame(File f, String title, String text, Point P) {
         frame = new Documento(title, f, P);
          frame.setSize(600,400);
          frame.setLocation(P); 
         editArea = new JTextArea();
          JScrollPane scroll = new JScrollPane(editArea);     
          editArea.setText("");
          editArea.addKeyListener(this);
          editArea.append(text);
          frame.add(scroll);
        frame.setVisible(true); //necessary as of 1.3
        desktop.add(frame);
        try {
            frame.setSelected(true);
        } catch (java.beans.PropertyVetoException e) {}
    //Quit the application.
    protected void quit() {
        System.exit(0);
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        //JFrame.setDefaultLookAndFeelDecorated(true);
        //Create and set up the window.
        mainGUI frame = new mainGUI();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Display the window.
        frame.setVisible(true);
    public void keyTyped(KeyEvent k){}
    public void keyPressed(KeyEvent k)
         if(k.getKeyCode()==10)
              editArea.append("\r");           
    public void keyReleased(KeyEvent k){}
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
}here's the one that extends jinternalframe
import javax.swing.JInternalFrame;
import javax.swing.plaf.InternalFrameUI;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import java.io.*;
import java.util.*;
/* Used by mainGUI.java */
public class Documento extends JInternalFrame {
    static final int xOffset = 30, yOffset = 30;
     static JTextArea editArea;
     static int docNum = 0;
     static File file;
      *The constructer for a new documento
    public Documento(File file) {
        super("Document "+(++docNum),
              true, //resizable
              true, //closable
              true, //maximizable
              true);//iconifiable
        docNum++;
          this.file = file;
          setSize(600,400);
          setLocation(xOffset*(docNum%10), yOffset*(docNum%10));
//        setUI(new InternalFrameUI());
     *The constructor for an existing documento
    public Documento(String title, File file, Point p) {
        super(title,
              true, //resizable
              true, //closable
              true, //maximizable
              true);//iconifiable
          this.file = file;             
          setSize(600,400);          
          setLocation(p);
//        setUI(new InternalFrameUI());
    public int getNum()
         return docNum;
    public File getPath()
         return file;
}I know it's pretty lengthy...it's probably all messed up since I'm lost :p
Thanks if you could help me!

Answer 1

I would be glad to help, but first I need a clarification. If I understand properly, you have two Java classes that you have created: the "main GUI" (which is most likely a JFrame extension in which the constructor adds a JDesktopPane to the content pane) and "Documento" (which you say is a JInternalFrame extension).
My question is this: what do you mean by "save the current JInternalFrame"? Do you want to record its position, location, and identity? Do you want to save its contents?
Thanks. Good luck. ;)