问下为什么要加EventQueue.invokeLater解决方法

import java.awt.*;import javax.swing.*;public class Test {    public static void main(String[] args)    {        EventQueue.invokeLater(new Runnable()            {                public void run()                {                    JFrame frame = new JFrame();                    frame.setSize(400, 300);                    frame.setVisible(true);                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                }            });    }}