J2ME Uncaught Exception

Question

I plan to start my first lesson in j2me, and I download a simple book and I try my first program. When I take a second step to add commands, I face an error message which is:

uncaught exception java/lang/noclassdeffounderror: readfile.

So, would you please help me to understand this message? and how to solve it? Please find my code below.

import javax.microedition.midlet.*; 
import javax.microedition.lcdui.*; 
public class ReadFile extends MIDlet implements CommandListener 
{ 
    private Form form1; 
    private Command Ok, Quit; 
    private Display display; 
    private TextField text1; 
    public void startApp() 
    { 
        form1 = new Form( "TA_Pog" ); 
        Ok = new Command("Ok", Command.OK, 1); 
        Quit = new Command("Quit", Command.EXIT, 2); 
        form1.setCommandListener(this); 
        form1.addCommand(Ok); 
        form1.addCommand(Quit); 
        text1 = new TextField("Put Your Name :","His Name : " , 32, TextField.URL ); 
        form1.append(text1); 
        display = Display.getDisplay(this); 
        display.setCurrent(form1); 
    } 
    public void commandAction(Command c , Displayable d) 
    { 
        if (c == Ok) 
        { 
            Alert a = new Alert("Alert","This Alert from Ok Button", null, AlertType.ALARM); 
            a.setTimeout (3000); 
            display.setCurrent(a,this.form1); 
        } 
        else 
        { 
            this.notifyDestroyed(); 
        } 
    } 
    public void pauseApp() {} 
    public void destroyApp( boolean bool ) {} 
}

Note: the code above is taken exactly from a book.

Thanks in advance Besr regards

gnat gnat · Accepted Answer · 2012-01-03T16:46:00

uncaught exception java/lang/noclassdeffounderror: readfile.

I somehow doubt the message is exactly as you describe it. Does it look more like below?

uncaught exception java/lang/NoClassDefFoundError: ReadFile

Please keep in mind in Java it matters much whether you use lower or upper case letters. As long as you don't pay attention to stuff like that, you are likely be getting a lot of problems like that.

Now, take a closer look at your class name:

public class ReadFile //...

The exception you are getting most likely says that Java machine can't find the class you try to use. There is something wrong with your build/compilation.

J2ME Uncaught Exception

2 Answers