Java Swing - 如何动态添加排序的项目到JComboBox

import java.awt.BorderLayout;
import java.util.Arrays;
import java.util.Collections;
import java.util.Vector;

import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

public class Main extends JFrame {
  String[] items = { "one", "two", "three", "four", "five" };
  SortedComboBoxModel model = new SortedComboBoxModel(items);
  JComboBox comboBox = new JComboBox(model);
  JTextField textField = new JTextField(15);

  public Main() {
    textField.addActionListener(e -> {
      comboBox.addItem(textField.getText());
      textField.setText("");
      comboBox.showPopup();
    });

    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
    frame.add(comboBox, BorderLayout.SOUTH);
    frame.add(textField, BorderLayout.WEST);
    frame.add(new JLabel("Enter to add Item  "), BorderLayout.EAST);
    frame.pack();
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    new Main();
  }
}

class SortedComboBoxModel extends DefaultComboBoxModel {
  public SortedComboBoxModel() {
    super();
  }
  public SortedComboBoxModel(Object[] items) {
    Arrays.sort(items);
    int size = items.length;
    for (int i = 0; i < size; i++) {
      super.addElement(items[i]);
    }
    setSelectedItem(items[0]);
  }

  public SortedComboBoxModel(Vector items) {
    Collections.sort(items);
    int size = items.size();
    for (int i = 0; i < size; i++) {
      super.addElement(items.elementAt(i));
    }
    setSelectedItem(items.elementAt(0));
  }

  @Override
  public void addElement(Object element) {
    insertElementAt(element, 0);
  }

  @Override
  public void insertElementAt(Object element, int index) {
    int size = getSize();
    for (index = 0; index < size; index++) {
      Comparable c = (Comparable) getElementAt(index);
      if (c.compareTo(element) > 0) {
        break;
      }
    }
    super.insertElementAt(element, index);
  }
}