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My idea is to open this window passed as parameter without it losing any attribute, for example, I have the class :
public class Teste {
JFrame janela = new JFrame;
public ControllerJPreTransacao(JFrame janela) {
this.janela = janela;
initEvents();
}
private void initEvents(){
janela.setVisible(true); //NullPointerException
}
}
As they might notice the commentary, in certain part of the class the eclipse accuses NullPointerException
on the line I leave the janela
visible, which makes no sense, since I already instated it at the beginning of the class. Due to this error the eclipse does not even open the frame. What am I missing?
Take a good look at what you are doing. If you receive a Frame as parameter, why new Frame? Remove it
JFrame janela = new JFrame;
, since you are getting a window in the builder.– user28595
I’ve tried to do without that
new
, but the IDE continues to accuse the same error, on the same line ...– Daniel Santos
How are you starting this class? Jframe is being passed as null.
– user28595
Good ! This is exactly what was missing ! There was no instantiation of the window passed as parameter !
– Daniel Santos