Can't anyone answer this simple question?

Question

Guys,I want to know whether a GUI which is made using Swing can write files to disk,or ,in another way--does Swing support writing files to disk?(This is becoz applets do not support this feature)
Thannks in advance,
Avichal167

Answer 1

One thing to note...
Because the previous example is simple, I handled all the File IO operations in the same class as the GUI ...
You can how ever have the File IO done in a different class and tie it in to your GUI class...
Example... GUISample.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GUISample extends JFrame implements ActionListener{
        private JTextArea jtxArea;
        private JButton jbtn;
        private String[] bText = {"Read","Write"};
        private boolean bState = true;
        private FileHandler handler;
     public GUISample(){
             super("GUI Sample");
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          setLayout(new BorderLayout());
          jtxArea = new JTextArea(15,20);
          jtxArea.setEditable(true);
          jbtn = new JButton(bText[0]);
          jbtn.addActionListener(this);
          getContentPane().add(jtxArea,BorderLayout.CENTER);
          getContentPane().add(jbtn,BorderLayout.SOUTH);
          pack();
          setVisible(true);
          handler = new FileHandler(); // instantiates FileHandler
     /* both method from FileHandler return Strings to be displayed in the JTextArea */
     public void readAndDisplay(){
          jtxArea.setText(handler.readTheFile()); // calls method from FileHandler
     public void writeToFile(){
          jtxArea.setText(handler.writeTheFile(jtxArea.getText())); // calls method from FileHandler
     public void actionPerformed(ActionEvent ae){
            if ((ae.getSource() == jbtn)&&(bState)){
                  bState = false;
                  jbtn.setText(bText[1]);
                  readAndDisplay();
             else{
                       bState = true;
                       jbtn.setText(bText[0]);
                       writeToFile();
     public static void main(String[] args){
             GUISample gspl = new GUISample();
}Example... FileHandler.java
import java.io.*;
public class FileHandler {
private String theData;
public String readTheFile(){ // reads and returns data or message
         try{
             File afile = new File("test.txt");
                 FileInputStream fis = new FileInputStream(afile);
                  try{
                       byte[] strBuff = new byte[(int)afile.length()];
                       fis.read(strBuff);
                       try{
                            theData = new String(strBuff);
                            fis.close();
                       }catch(NullPointerException npe){theData = "Null Pointer Exception";}
                   }catch (IOException ioe){theData = "IO Exception";}
           }catch (FileNotFoundException fnfe){ theData = "File Not Found";}
     return theData;
     public String writeTheFile(String data){ // writes and returns a message
         try{
             File afile = new File("test.txt");
                 FileOutputStream fos = new FileOutputStream(afile);
               try{
                       try{
                       fos.write(data.getBytes());
                       fos.close();
                       theData = "File Saved";
                }catch(NullPointerException npe){theData = "Null Pointer Exception";}
                   }catch (IOException ioe){theData = "IO Exception";}
           }catch (FileNotFoundException fnfe){theData = "File Not Found";}
           return theData;
}and of course you can use the same Test.txt file...
As you can see from this example, I have one class create and handle the GUI and the second class handles all the File IO operations...
So to better answer your first question, Swing and AWT and Applets can be used to create GUIs... and as far as File IO, all three can have code or be couples with a class that does File IO operations...
The only restriction is with Applets where by default the SecurityMananger does not allow File IO operations...
Notice the word "default", this means Applets are capable of doing File IO, if you do some extra coding and policy work... ( my terminology may be off on this)
But as stated earlier, I am not well versed enough in Applets to give you assistance in creating a Signed Applet that can... soon I will, just not at this time...
- MaxxDmg...
- ' He who never sleeps... '