/************未完成*************/


package javalessons;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.ComponentOrientation;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;

public class Calculator extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private final int WIDTH = 480;
    private final int HEIGHT = 300;
    private Panel panel1, panel2;
    private JTextField textField;
    private JButton[] button;
    private String[] buttonText = { "7", "8", "9", "+", "C", "4", "5", "6",
            "-", "退格", "1", "2", "3", "*", "1/X", "0", "+/-", ".", "/", "=" };
    /** **************** 当按下的按钮是操作符时，operator 为 true ******************* */
    public static boolean operator;
    private int count = 0;// count = 0 为第一次输入
    private String text = "";
    private double total = 0;// 存放结果
    private int symbol = 0;// +、-、*、/分别对应 1、2、3、4

    public static void main(String args[]) {
        try {
            Calculator frame = new Calculator();
            frame.setVisible(true);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Create the frame
     */
    public Calculator() {
        super();
        setTitle("计算器");
        Toolkit toolkit = Toolkit.getDefaultToolkit();
        Dimension screenSize = toolkit.getScreenSize();
        setBounds((screenSize.width - WIDTH) / 2,
                (screenSize.height - HEIGHT) / 2, WIDTH, HEIGHT);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        panel1 = new Panel();
        panel2 = new Panel();

        setLayout(new BorderLayout());
        textField = new JTextField("0", 30);
        textField.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
        textField.setFont(new Font("", Font.BOLD, 22));
        textField.setForeground(Color.BLUE);
        textField.setEditable(false);
        textField.setBackground(Color.WHITE);
        panel1.setLayout(new GridLayout(1, 1));
        panel1.add(textField);

        button = new JButton[20];
        for (int i = 0; i < button.length; i++) {
            button[i] = new JButton();
            button[i].setText(buttonText[i]);
            button[i].setFont(new Font("", Font.BOLD, 22));
            button[i].setForeground(Color.BLUE);
            panel2.add(button[i]);
            button[i].addActionListener(this);
        }
        button[3].setForeground(Color.RED);
        button[4].setForeground(Color.RED);
        button[8].setForeground(Color.RED);
        button[9].setForeground(Color.RED);
        button[13].setForeground(Color.RED);
        button[18].setForeground(Color.RED);
        button[19].setForeground(Color.RED);
        panel2.setLayout(new GridLayout(4, 5));
        add(panel1, "North");
        add(panel2, "Center");
    }

    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        if (e.getSource() == this.button[0]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("7");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "7");
            }
        }
        if (e.getSource() == this.button[1]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("8");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "8");
            }
        }
        if (e.getSource() == this.button[2]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("9");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "9");
            }
        }
        if (e.getSource() == this.button[5]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("4");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "4");
            }
        }
        if (e.getSource() == this.button[6]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("5");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "5");
            }
        }
        if (e.getSource() == this.button[7]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("6");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "6");
            }
        }
        if (e.getSource() == this.button[10]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("1");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "1");
            }
        }
        if (e.getSource() == this.button[11]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("2");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "2");
            }
        }
        if (e.getSource() == this.button[12]) {
            if (operator || count == 0 || textField.getText().equals("0")) {
                textField.setText("3");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                textField.setText(text + "3");
            }
        }
        /** *********** 对 textField 中本为“0”时进行特殊处理 ************* */
        if (e.getSource() == this.button[15]) {
            if (operator || count == 0) {
                textField.setText("0");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                if (Float.parseFloat(text) != 0) {
                    textField.setText(text + "0");
                } else {
                    if (text.trim().indexOf(".") == -1) {
                        textField.setText(text);
                    } else {
                        textField.setText(text + "0");
                    }
                }
            }
        }
        if (e.getSource() == this.button[4]) {
            textField.setText("0");
            count = 0;
            total=0;
            operator = true;
        }
        /** *********** 处理小数点，在一个数不能有一个以上的小数点 ************* */
        if (e.getSource() == this.button[17]) {
            if (operator || count == 0) {
                textField.setText("0.");
                operator = false;
                count = 1;
            } else {
                text = textField.getText();
                if (text.trim().indexOf(".") == -1) {
                    textField.setText(text + ".");
                } else {
                    textField.setText(text);
                }
            }
        }
        /** *************处理1/X************* */
        if (e.getSource() == this.button[14]) {
            operator = true;
            if (count != 0) {
                total = 1 / Double.parseDouble(textField.getText());
                textField.setText(total + "");
            }
        }
        /** *********处理“=”********** */
        if (e.getSource() == this.button[19]) {
            operator = true;
            if (count != 0) {
//                if (count != 1) {
                    total += Double.parseDouble(textField.getText());
                    textField.setText(total + "");
//                }
            }
        }
        /** ********获取“-”前的数值********* */
        if (e.getSource() == this.button[3]) {
            operator = true;
            count = 1;
            total = Double.parseDouble(textField.getText());
            textField.setText(textField.getText());
            symbol = 1;
        }
        /** ********获取“-”前的数值********* */
        if (e.getSource() == this.button[8]) {
            operator = true;
            count = 1;
            total = Double.parseDouble(textField.getText());
            textField.setText(textField.getText());
            symbol = 2;
        }
        /** ********获取“*”前的数值********* */
        if (e.getSource() == this.button[13]) {
            operator = true;
            count = 1;
            total = Double.parseDouble(textField.getText());
            textField.setText(textField.getText());
            symbol = 3;
        }
        /** ********获取“/”前的数值********* */
        if (e.getSource() == this.button[18]) {
            operator = true;
            count = 1;
            total = Double.parseDouble(textField.getText());
            textField.setText(textField.getText());
            symbol = 4;
        }
        switch (symbol) {
        case 1:// 计算加法
        {
            double ad = total + Double.parseDouble(textField.getText());
            textField.setText(ad + "");
            count = 0;
            text = "";
            break;
        }
        case 2:// 计算减法
        {
            double ad = total - Double.parseDouble(textField.getText());
            textField.setText(String.valueOf(ad));
            count = 0;
            text = "";
            break;
        }
        case 3:// 计算乘法
        {
            double ad = total * Double.parseDouble(textField.getText());
            textField.setText(ad + "");
            count = 0;
            text = "";
            break;
        }
        case 4:// 计算除法
        {
            double ad = total / Double.parseDouble(textField.getText());
            textField.setText(ad + "");
            count = 0;
            text = "";
            break;
        }
        }
        System.out.println(operator);
    }
}


觉得这样写太多重复的代码了
哪位坛友给个好的建议？
大四就好找工作了还要做这么多实验，还全是要做界面的，郁闷