I can't add border to JMenu button, looks like setBorder methods works only with JMenuItem.
import javax.swing.*;
import java.awt.*;
public class Test extends JFrame {
public Test() {
initUI();
}
private void initUI() {
// creating menuBar
JMenuBar menuBar = new JMenuBar();
// creating menu and adding border
JMenu menu = new JMenu("Some menu");
menu.setBorder(BorderFactory.createLineBorder(Color.black, 3));
// creating item and adding border (the same way)
JMenuItem item1 = new JMenuItem("Some item");
item1.setBorder(BorderFactory.createLineBorder(Color.black, 3));
// adding all together
menu.add(item1);
menuBar.add(menu);
setJMenuBar(menuBar);
// basic settings for the window
setTitle("Testing JMenu");
setSize(360, 250);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
Test test =new Test();
test.setVisible(true);
});
}
}
The result is as follows; I expected black frames around both JMenu and JMenuItem
JMenu is more complex. You might have to edit it like this:
UIManager.put("PopupMenu.border", new LineBorder(Color.RED));
You can check the javadocs for UIManager at https://docs.oracle.com/javase/8/docs/api/javax/swing/UIManager.html
You can then check the file ${java.home}/lib/swing.properties
for similar properties.