简单计算器四则混合运算

四则混合运算 JPanel jp = new JPanel(); JPanel jp1 = new JPanel(); JPanel jp2 = new JPanel(); JPanel jp3 = new JPanel(); JPanel jp4 = new JPanel(); JPanel jp5 = new JPanel(); JPanel jp6 = new JPanel(); JPanel jp7 = new JPanel(); JTextField jtf = new JTextField(18); JButton[] jb = new JButton[18];