Categories: S60 3rd Edition, Feature Pack 2 | Java ME | MIDP 2.0 | ESWT | File Connection and PIM API (JSR-75) | Code Examples

This page was last modified 22:45, 19 May 2008.

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Overview

This code snippet demonstrates how to use eSWT's FileDialog class in Java ME. A FileDialog can be opened and when a file is selected, its size is shown on the screen. The following section contains the complete code for compiling and running the example application.

Source code

import javax.microedition.midlet.*;
import org.eclipse.ercp.swt.mobile.Command;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.layout.FillLayout;
import javax.microedition.io.file.FileConnection;
import javax.microedition.io.Connector;
import java.io.IOException;
 
public class FileDialogMIDlet extends MIDlet implements Runnable, SelectionListener {
    private Thread UIThread;
    private Display display;
    private Shell formShell;
    private boolean exiting = false;
    private Command fileCommand;
    private Command exitCommand;
    private Text text;
    private String textString = "FileDialogMIDlet";
 
    public void startApp() {
        // Create the eSWT UI thread. 
        if(UIThread == null) {
            UIThread = new Thread(this);
            UIThread.start();
        }
    }
 
    public void pauseApp() {
    }
 
    public void destroyApp(boolean unconditional) {
        // Make the event loop exit in the eSWT UI thread.
        exitEventLoop();
        // Wait for the eSWT UI thread to die. 
        try {
            UIThread.join();
        } catch(InterruptedException e) {
        }
    }
 
    void exitEventLoop() {
        exiting = true;
        Display.getDefault().wake();
    }
 
    // The eSWT UI Thread. 
    public void run() {
        display = new Display();
        FillLayout fillLayout = new FillLayout();
        formShell = new Shell(display);
        formShell.setLayout(fillLayout);
        formShell.open();
        Composite form = new Composite(formShell, SWT.NONE);
        form.setLayout(fillLayout);
        text = new Text(form, SWT.READ_ONLY | SWT.WRAP);
        text.setText(textString);
        fileCommand = new Command(formShell, Command.SELECT, 0);
        fileCommand.setText("Open FileDialog");
        fileCommand.addSelectionListener(this);
        exitCommand = new Command(formShell, Command.EXIT, 0);
        exitCommand.setText("Exit");
        exitCommand.addSelectionListener(this);
        formShell.redraw();
 
        // Execute the eSWT event loop. 
        while(!exiting) {
            if(!display.readAndDispatch()) {
                display.sleep();
            }
        }
 
        // Clean up and destroy the MIDlet.
        display.dispose();
        notifyDestroyed();
    }
 
    public void widgetDefaultSelected(SelectionEvent e) {
    }
 
    public void widgetSelected(SelectionEvent e) {
        if (e.widget.equals(fileCommand)) {
            openFileDialog();
        }
        if (e.widget.equals(exitCommand)) {
            // Exit command selected, exit the event loop. 
            exitEventLoop();        
        }
    }
    
    public void openFileDialog() {
        FileDialog fDialog = new FileDialog(formShell);
        fDialog.open();
        String filterPath = fDialog.getFilterPath();
        String temp = filterPath.replace('\\', '/'); // '\‘ characters are replaced with '/'
        filterPath = temp;
        String fileName = fDialog.getFileName();
        String path = "file:///" + filterPath + fileName;
        // path is for example: file:///C:/Data/Images/image.png, this can be used as file    
        // URL for FileConnection
        if (!path.equals("file:///")) { 
            // Path equals "file:///", if file dialog is canceled.
            try {
                FileConnection fc = (FileConnection) Connector.open(path, Connector.READ);
                if (!fc.isDirectory()) {
                    textString = "File size: " + fc.fileSize() + " bytes";
                    text.setText(textString);            
                }
            } catch (IOException ioe) { 
                // Thrown if an I/O error occurs or if the method is invoked on a directory.
                // Note: It is not possible to select a directory in FileDialog.
                textString = "IOException: " + ioe.getMessage();
                text.setText(textString);
            }
            catch (SecurityException se) { 
                // Thrown if the security of the application does not have read access for
                // the file.
                textString = "SecurityException: " + se.getMessage();
                text.setText(textString);
            }
            formShell.redraw();        
        }
    }
}

Postconditions

When a FileDialog is opened and a file is selected in it, the file size is shown on the screen.

See also

• eSWT