Java Swing - 如何按索引预选项目

import javax.swing.JComboBox;
import javax.swing.JFrame;

public class Main {

  public static void main(String[] args) {
    JComboBox<String> my = new JComboBox<>(new String[] {
        "HELLO WORLD", "w3cschool.cn" });
    JFrame frame = new JFrame("");
    frame.add(my);
    frame.pack();
    frame.setVisible(true);
    my.setSelectedIndex(1);
  }
}