import java.io.IOException;
import java.util.Enumeration;
import javax.microedition.io.Connection;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.io.file.FileSystemRegistry;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;

public class FileBrowser extends MIDlet
    implements CommandListener
{

    private List browser;
    private Display display;
    private Command exit;
    private String currDirName;
    private FileConnection fc;
    private Enumeration enumeration;

    public FileBrowser()
    {
        currDirName = "/";
    }

    public void startApp()
    {
        browser = new List("FileBrowser", 3);
        exit = new Command("Exit", 7, 3);
        browser.addCommand(exit);
        browser.setCommandListener(this);
        showCurrDir();
        display = Display.getDisplay(this);
        display.setCurrent(browser);
    }

    public void pauseApp()
    {
    }

    public void destroyApp(boolean flag)
    {
    }

    public void commandAction(Command command, Displayable displayable)
    {
        if(command == List.SELECT_COMMAND)
        {
            int i = browser.getSelectedIndex();
            String s = browser.getString(i);
            traverseDirectory(s);
            showCurrDir();
        }

        if(command == exit)
            notifyDestroyed();
    }

    private void showCurrDir()
    {
        try
        {
            browser.deleteAll();
            if("/".equals(currDirName))
            {
                enumeration = FileSystemRegistry.listRoots();
            } else
            {
                String s = "file:///" + currDirName;
                fc = (FileConnection)Connector.open(s);
                enumeration = fc.list();
                browser.append("..", null);
            }
            browser.setTitle(currDirName);
            String s1;
            for(;enumeration.hasMoreElements(); browser.append(s1, null));
                s1 = (String)enumeration.nextElement();
            if(fc != null)
                fc.close();
        }
        catch(IOException ioexception) { }
    }
    private void traverseDirectory(String s)
    {
        if(currDirName.equals("/"))
            currDirName = s;
        else
        if(s.equals(".."))
        {
            int i = currDirName.lastIndexOf('/', currDirName.length() - 2);
            if(i != -1)
                currDirName = currDirName.substring(0, i + 1);
            else
                currDirName = "/";
        } else
        {
            currDirName = currDirName + s;
        }
    }
}