Java Swing - 如何将自定义对象填充到JComboBox

import java.awt.BorderLayout;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Main extends JFrame {
  JLabel label;
  JComboBox combo;
  public static void main(String args[]) {
    new Main();
  }

  public Main() {
    label = new JLabel("Select a Customer");
    add(label, BorderLayout.NORTH);

    Customer customers[] = new Customer[6];
    customers[0] = new Customer("A", 1);
    customers[1] = new Customer("B", 6);
    customers[2] = new Customer("C", 2);
    customers[3] = new Customer("D", 3);
    customers[4] = new Customer("E", 4);
    customers[5] = new Customer("F", 5);

    combo = new JComboBox(customers);
    combo.addItemListener(e -> {
      Customer c = (Customer) e.getItem();
      label.setText("You selected customer id: " + c.getId());
    });
    JPanel panel = new JPanel();
    panel.add(combo);
    add(panel, BorderLayout.CENTER);

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(400, 200);
    setVisible(true);
  }
}

class Customer {
  private String name;
  private int id;

  public Customer(String name, int id) {
    this.name = name;
    this.id = id;
  }

  public String toString() {
    return getName();
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public int getId() {
    return id;
  }

  public void setId(int id) {
    this.id = id;
  }
}