Bring JPanel to front of other objects in java (SWING)

Question

I want to make a loading message when an app processes, so I used a JPanel over a JTree. But when the user clicks on the JPanel, the <

Answer 1

Jpanel main = new JPanel();
Jpanel a = new JPanel();
JPanel b = new Jpanel();

main.add(a);
main.add(b);

at this point the object:

a -> 0 ( index)
b -> 1 (index)

main.getComponentCount() = 2

main.setComponentZorder(b,0);


a -> 1
b -> 0;

b OVER
a DOWN