java计算器源程序

importjava.awt.*;importjava.lang.*;importjavax.swing.*;importjavax.swing.event.*;importjava.awt.event.*;importjava.text.DecimalFormat;publicclassCalculatorimplementsActionListener{JFrameframe;JTextFieldtextAnswer;JPanelpanel,panel1,panel2,panel3;JLabellabelMemSpace;//控制面板的形状JButtonbut