你能写一段关于上述问题代码吗

当然可以，以下是一个简单的Java计算器GUI代码，包括标准模式和科学模式：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Calculator extends JFrame implements ActionListener {

    private JTextField display;
    private JPanel buttonPanel;
    private JButton[] buttons;
    private String[] buttonLabels = {
            "7", "8", "9", "+",
            "4", "5", "6", "-",
            "1", "2", "3", "*",
            "0", ".", "=", "/"
    };

    private JButton sciButton;
    private boolean sciMode = false;


    public Calculator() {
        display = new JTextField(20);
        display.setEditable(false);

        buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4, 4));

        buttons = new JButton[buttonLabels.length];
        for (int i = 0; i < buttonLabels.length; i++) {
            buttons[i] = new JButton(buttonLabels[i]);
            buttons[i].addActionListener(this);
            buttonPanel.add(buttons[i]);
        }

        sciButton = new JButton("Sci");
        sciButton.addActionListener(this);

        Container contentPane = getContentPane();
        contentPane.add(display, BorderLayout.NORTH);
        contentPane.add(buttonPanel, BorderLayout.CENTER);
        contentPane.add(sciButton, BorderLayout.SOUTH);

        pack();
    }


    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        if (command.equals("Sci")) {
            sciMode = !sciMode;
            if (sciMode) {
                buttonLabels = new String[]{
                        "7", "8", "9", "+",
                        "4", "5", "6", "-",
                        "1", "2", "3", "*",
                        "0", ".", "=", "/",
                        "sqrt", "x^2", "log"
                };
            } else {
                buttonLabels = new String[]{
                        "7", "8", "9", "+",
                        "4", "5", "6", "-",
                        "1", "2", "3", "*",
                        "0", ".", "=", "/"
                };
            }
            for (int i = 0; i < buttonLabels.length; i++) {
                buttons[i].setText(buttonLabels[i]);
            }
        } else if (command.equals("=")) {
            String expression = display.getText();
            double result = eval(expression);
            display.setText(Double.toString(result));
        } else {
            display.setText(display.getText() + command);
        }
    }


    public static double eval(String expression) {
        return new Object() {
            int pos = -1, ch;

            void nextChar() {
                ch = (++pos < expression.length()) ? expression.charAt(pos) : -1;
            }

            boolean eat(int charToEat) {
                while (ch == ' ') nextChar();
                if (ch == charToEat) {
                    nextChar();
                    return true;
                }
                return false;
            }

            double parse() {
                nextChar();
                double x = parseExpression();
                if (pos < expression.length()) throw new RuntimeException("Unexpected: " + (char) ch);
                return x;
            }

            double parseExpression() {
                double x = parseTerm();
                for (;;) {
                    if      (eat('+')) x += parseTerm(); // addition
                    else if (eat('-')) x -= parseTerm(); // subtraction
                    else return x;
                }
            }

            double parseTerm() {
                double x = parseFactor();
                for (;;) {
                    if      (eat('*')) x *= parseFactor(); // multiplication
                    else if (eat('/')) x /= parseFactor(); // division
                    else return x;
                }
            }

            double parseFactor() {
                if (eat('+')) return parseFactor(); // unary plus
                if (eat('-')) return -parseFactor(); // unary minus

                double x;
                int startPos = this.pos;
                if (eat('(')) { // parentheses
                    x = parseExpression();
                    eat(')');
                } else if ((ch >= '0' && ch <= '9') || ch == '.') { // numbers
                    while ((ch >= '0' && ch <= '9') || ch == '.') nextChar();
                    x = Double.parseDouble(expression.substring(startPos, this.pos));
                } else {
                    throw new RuntimeException("Unexpected: " + (char) ch);
                }

                if (eat('^')) x = Math.pow(x, parseFactor()); // exponentiation
                else if (eat('s')) x = Math.sqrt(x); // square root
                else if (eat('x')) x = Math.pow(x, 2); // power of 2
                else if (eat('l')) x = Math.log(x); // natural logarithm

                return x;
            }
        }.parse();
    }


    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        calculator.setVisible(true);
    }

}

这段代码创建了一个具有标准模式和科学模式的计算器GUI，用户可以在文本框中输入表达式，并使用按钮计算结果。按钮的文本将根据当前模式动态更改，用户可以使用Sci按钮在标准模式和科学模式之间切换。