import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Main {
public static void main(String args[]) {
JPanel p = new JPanel();
p.setLayout(new GridLayout(2, 1));
JList<String> lista = new JList<>(new String[] {"1", "2", "3", "4"});
p.add(new JScrollPane(lista));
JComboBox<String> combo = new JComboBox<>();
for (int i = 0; i < 100; i++) {
combo.addItem(Integer.toString(i));
p.add(combo);
}
JFrame f = new JFrame();
f.getContentPane().add(p, BorderLayout.CENTER);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(200, 200);
f.setVisible(true);
}
}