java图形界面开发,简单的计算器

packageday16.pm;importjava.awt.BorderLayout;importjava.awt.Color;importjava.awt.FlowLayout;importjava.awt.Font;importjava.awt.GridLayout;importjavax.swing.JButton;importjavax.swing.JFrame;importjavax.swing.JPanel;importjavax.swing.JTextField;publicclassCalcultorA{publicstaticvoidmain(String[]args){