How do I get a MessageBox like information window to appear in Java?

Question

I'm learning Java and I have no idea how to do this.

I dragged a button on the form in Netbeans, double clicked it and it created this event:

@Action
public void HelloClickMethod() 
{
    JOptionPane.showMessageDialog(this, "The message!", "This is supposed to be the MessageBox title."); 
}

This is the exception the IDE brings up.

Cannot find symbol. Symbol: showMessageDialog()

Edit 1> Now I changed it to this:

@Action
public void HelloClickMethod()
{
    JOptionPane.showMessageDialog(this, "The message!", "This is supposed to be the MessageBox title.",JOptionPane.ERROR_MESSAGE);
}

However the IDE is saying I have an error in the word 'this'. "Cannot find symbol". I don't understand. Why is it so dificult and why are the errors so esoteric. :P

Answer 1

The showMessageDialog method does not take 3 parameters. Try this:

  JOptionPane.showMessageDialog(this, "The message!", "This is supposed to be the MessageBox title.", JOptionPane.ERROR_MESSAGE);

There are 3 methods named showMessageDialog, one with 2 parameters (component and message), 4 parameters (component, message, title, message type) and 5 parameters (component, message, title, message type, icon).

Answer 2

I can think of the following cause: you might not be "importing" the package containing JOptionPane. Try:

 import javax.swing.*;

On top of your source file. Or, use

javax.swing.JOptionPane.showMessageDialog(this, "The message!", "This is supposed to be the MessageBox title.", JOptionPane.ERROR_MESSAGE);

After questioner edit:

Other cause is the location of the method, if you are in an static context, you can't use this.

Answer 3

I've been creating a message box using the jOptionPane, all i want is to remove the jOptionPane on the form when i run the application. how would i do that?

jOPtionPane1.showMessageBox(frame, "My message","My title",null);

i am using netbeans 6.9, can you help me to hide the jOptionPane when the application run..

and since were in the messageBox, can you show some code for the showDialogBox,showinputBox

thanks..

here's my email

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