结组开发

1、第一阶段目标：重构四则运算-- 能把计算的功能封装起来，通过API 接口调用计算方法。

定义一个计算核心类：把四则运算的计算功能包装在一个模块中 (这个模块可以是一个类 Class,  一个DLL等等)。

2、 第二阶段目标 - 通过测试程序和API 接口测试其简单的加减乘除功能。并能看到代码覆盖率。

3、第三阶段目标 – 定义异常处理。

如果输入是有错误的，例如 “1 ++ 2”， 在数值范围是 -1000 .. 1000 的时候，传进去 “10000 + 32768 * 3”,  或者是 “ 248.04 / 0”  怎么办? 怎么告诉函数的调用者 “你错了”?  把返回的字符串定义为 “-1” 来表示？ 那么如果真的计算结果是 “-1” 又怎么处理呢?建议这个时候，要定义各种异常 (Exception)， 让 Core 在碰到各种异常情况的时候，能告诉调用者 - 你错了！

代码:

frame.java:

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Font;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;


import szys.frame;

import java.awt.EventQueue;

public class frame {

    private JFrame frame;
    private JTextField textField;
    private JTextField textField_1;
    private JTextField textField_2;
    private JTextField textField_3;
    private JTextField textField_4;
    private JTextField textField_5;
    frame f;
    
    int a;
    int b;
    char []op={'+','-','*','/'};
    String Sa;
    String Sb;
    int result;
    static int i = (int) (Math.random() * 3);
    

    Expression expression = new Expression();
    private JButton btnNewButton_1;


    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    frame window = new frame();
                    window.frame.setVisible(true);System.out.print(i);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     * @throws Yichang 
     */
    public frame() throws Yichang {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() throws Yichang{
        frame = new JFrame();
        frame.setBounds(100, 100, 517, 352);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JPanel panel = new JPanel();
        frame.getContentPane().add(panel, BorderLayout.CENTER);
        panel.setLayout(null);
        
        JLabel lblNewLabel = new JLabel("u56DBu5219u8FD0u7B97u56685.2");
        lblNewLabel.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        lblNewLabel.setBounds(141, 0, 208, 57);
        panel.add(lblNewLabel);
        
        textField = new JTextField();
        textField.setHorizontalAlignment(SwingConstants.CENTER);
        textField.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        textField.setBounds(56, 82, 88, 45);
        panel.add(textField);
        textField.setColumns(10);
        
        textField_1 = new JTextField();
        textField_1.setHorizontalAlignment(SwingConstants.CENTER);
        textField_1.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        textField_1.setColumns(10);
        textField_1.setBounds(220, 82, 88, 45);
        panel.add(textField_1);
        
        textField_2 = new JTextField("=");
        textField_2.setHorizontalAlignment(SwingConstants.CENTER);
        textField_2.setEditable(false);
        textField_2.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        textField_2.setColumns(10);
        textField_2.setBounds(318, 82, 36, 45);
        panel.add(textField_2);
        
        textField_3 = new JTextField();
        textField_3.setHorizontalAlignment(SwingConstants.CENTER);
        textField_3.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        textField_3.setColumns(10);
        textField_3.setBounds(371, 82, 88, 45);
        panel.add(textField_3);
        
        JButton btnNewButton = new JButton("u505Au5B8Cu4E86");
        btnNewButton.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        btnNewButton.setBounds(188, 156, 131, 45);
        panel.add(btnNewButton);
        
        JLabel lblNewLabel_1 = new JLabel("u8BA1u7B97u7ED3u679C");
        lblNewLabel_1.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        lblNewLabel_1.setBounds(56, 222, 131, 35);
        panel.add(lblNewLabel_1);
        
        textField_4 = new JTextField();
        textField_4.setFont(new Font("微软雅黑", Font.PLAIN, 20));
        textField_4.setColumns(10);
        textField_4.setBounds(188, 222, 161, 35);
        panel.add(textField_4);
        
        textField_5 = new JTextField();
        textField_5.setHorizontalAlignment(SwingConstants.CENTER);
        textField_5.setEditable(false);
        textField_5.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        textField_5.setText(String.valueOf(op[i]));
        textField_5.setColumns(10);
        textField_5.setBounds(159, 82, 44, 45);
        panel.add(textField_5);
        
        a = expression.geta();
        Sa = String.valueOf(a);
        textField.setText(Sa);
        
        b = expression.getb();
        Sb = String.valueOf(b);
        textField_1.setText(Sb);
        
        btnNewButton_1 = new JButton("u518Du6765 ");
        btnNewButton_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                
                try {
                        f = new frame();
                } catch (Yichang e1) {
                    // TODO 自动生成的 catch 块
                    e1.printStackTrace();
                }
                frame.dispose();
                f.frame.setVisible(true);
                
            }
        });
        btnNewButton_1.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        btnNewButton_1.setBounds(366, 222, 107, 36);
        panel.add(btnNewButton_1);
        

        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0){
                int n3=Integer.valueOf(textField_3.getText().toString());    
                switch(op[i])
                {
                    case '+':result = expression.expressionadd();break;
                    case '-':result = expression.expressionmin();break;
                    case '*':result = expression.expressionchen();break;
                    case '/':result = expression.expressionchu();break;
                }
                if(textField_3.getText()!="")
                {
                     if(result==n3)
                        {
                            textField_4.setText(" 正确");
                        }
                         else
                        {
                            textField_4.setText(" 错误!答案为"+result);
                        }
                }     
                try {
                    if(textField_3.getText()=="")
                    throw new Yichang("不能为空！");
                    } catch (Yichang e) {
                        // TODO 自动生成的 catch 块
                        e.printStackTrace();
                    }
                
                /*try {
                 if(n3<0)
                
                        throw new Yichang("不可能是负数!");
                    } catch (Yichang e) {
                        // TODO 自动生成的 catch 块
                        e.printStackTrace();
                    }*/

                }
        });
    }
}

input.java:

import java.util.*;

public class Input {
    public int a; 
    static Scanner in=new Scanner(System.in);
    public void seta(int intput){
        a = intput;
    }
    public Input()
    {
        try{
            a = in.nextInt();
        }
        catch(InputMismatchException e)
        {  
            System.err.println("
错误！  请你输入一个整数!
");
        }
    }
    public int getinput()
    {
        return a;
    }
    
}

yichang.java:

class Yichang extends Exception 
{  
    public Yichang(String msg)      
    {  
        super(msg);  
    }  
}  

Expression.java:

import java.util.*;

import szys.Input;
public class Expression 
{
    private int a = (int)(Math.random() * Math.pow(10,2)-1);
    private int b = (int)(Math.random() * Math.pow(10,2)-1);
    private int op;
    static int c;//用户答案
    int answer;//答案
    int answer1;
    static Scanner in=new Scanner(System.in);
    
public int geta()
{
    return a;
}

public void seta(int a)
{
    this.a = a;
}

public int getb()
{
    return b;
}

public void setb(int b)
{
    this.b = b;
}

public int expressionadd()
{
    answer = a+b;
    return answer;
}
public int expressionmin()
{
    answer = a-b;
    return answer;
}
public int expressionchen()
{
    answer = a*b;
    return answer;
}
public int expressionchu()
{
    b = (b == 0 ? b = 1 +(int)(Math.random() * Math.pow(10,2)-1):b);//排除除法被除数为0的情况
    answer = a/b;
    return answer;
}
public static void main(String[] args){
    int answer;
    Expression expression = new Expression();
    
    //answer = expression.answer;
    //Input input = new Input();
    //Expression.c = input.a;
    /*try{
        Expression.c = in.nextInt();
    }
    catch(InputMismatchException e)
    {   System.err.println("
错误！  ,请你输入一个整数");
    }*/
    //if(answer==c)
/*    {
        System.out.print("答对了");
    }
    else System.out.print("答错了");*/
    //System.out.print("answer="+answer);
}
}

运行截图：