Java – use the layout to set the panel in the center of the screen

I try to set the position of the child panel in the center of the parent panel by using

parent_panel.setLayout(new BorderLayout());
parent_panel.add(child_panel,BorderLayout.CENTER);

But it will be added in the middle of the horizontal screen, but vertically at the top

How do I add it vertically and horizontally to the center of the screen? What do I need to do?

Solution

If I understand correctly, you want an interface like this:

+-------- Parent panel --------+
|                              |
|                              |
|    +--- Child panel ----+    |
|    |                    |    |
|    |                    |    |
|    |                    |    |
|    |                    |    |
|    +--------------------+    |
|                              |
|                              |
+------------------------------+

... and you have not added other components to the parent panel

If this is the case, you have two choices I know (based on this question, I have obviously answered):

>Use gridbaglayout with an empty GridBagConstraints object as follows:

parent_panel.setLayout(new GridBagLayout());
parent_panel.add(child_panel,new GridBagConstraints());

>Use @ r_ 866_ 2419@Layout , as follows:

parent_panel.setLayout(new @R_866_2419@Layout(parent_panel,@R_866_2419@Layout.PAGE_AXIS));
@R_866_2419@ horizontal@R_866_2419@ = @R_866_2419@.createHorizontal@R_866_2419@(); 
horizontal@R_866_2419@.add(@R_866_2419@.createHorizontalGlue()); 
horizontal@R_866_2419@.add(child_panel); 
horizontal@R_866_2419@.add(@R_866_2419@.createHorizontalGlue()); 
@R_866_2419@ vertical@R_866_2419@ = @R_866_2419@.createVertical@R_866_2419@(); 
vertical@R_866_2419@.add(@R_866_2419@.createVerticalGlue()); 
vertical@R_866_2419@.add(horizontal@R_866_2419@); // one inside the other
vertical@R_866_2419@.add(@R_866_2419@.createVerticalGlue());