Adding JPanel to JFrame

Question

I have a program in which a JPanel is added to a JFrame:

public class Test{

    Test2 test = new Test2();
    JFrame frame = new JFrame();

    Test(){

    ...         


        

Answer 1

Test2 test = new Test2();
...
frame.add(test, BorderLayout.CENTER);

Are you sure of this? test is NOT a component! To do what you're trying to do you should let Test2 extend JPanel !