Junit的简单使用

1 实验

刚学了下利用进行Junit的单元测试，现在来记录下。

JUnit是一个开源的Java编程语言的单元测试框架，应用Junit可以快速高效的对代码进行测试。

现在主要利用JUnit测试如下代码，代码比较简单就不注释了，可以看出代码主要分为两个类BankAccount 和BankAccountGold

public class BankAccount
{
    String AccountNumber;
    String AccountName;
    String ID;
    String Password;
    double TotalMoney;
 
    public BankAccount(String AccountNumber, String AccountName, String ID, String Password)
    {
        this.AccountNumber = AccountNumber;
        this.AccountName = AccountName;
        this.ID = ID;
        this.Password = Password;      
    }
     
    public void Balance(String AccountNumber)
    {
            System.out.println("PLEASE FIND YOUR BALANCE INFORMATION");
            System.out.println("Account name:" + AccountName);
            System.out.println("Account number:" + AccountNumber);
            System.out.println("Your balance:" + TotalMoney);
    }
     
    public void Deposit(double AddMoney)
    {
        try
        {
            if(AddMoney < 0) throw new RuntimeException();
            this.TotalMoney += AddMoney;                    
        }
        catch(RuntimeException except)
        {
            System.out.println("Failed to deposite, money should be larger than 0");
        }       
        System.out.println("Deposited money succeeded, the total money is:" + TotalMoney);
    }
 
    public void Withdraw(double GetMoney)
    {        
        try
        {
            if(GetMoney > this.TotalMoney ) throw new RuntimeException();
            this.TotalMoney -= GetMoney;
            System.out.println("You have withdrawed money:" + GetMoney);
        }
        catch (RuntimeException except)
        {
            System.out.println("Error! you don't have enough balance");
        }
    }  
}
 
class BankAccountGold extends BankAccount
{
    public BankAccountGold(String AccountNumber, String AccountName, String ID, String Password)
    {
        super(AccountNumber,AccountName,ID,Password);   
    }
    public void Withdraw(double GetMoney, double overdraft)
    {
        overdraft = this.TotalMoney - GetMoney;
        if(overdraft > 0)
        {
            this.TotalMoney = overdraft;
            System.out.println("Succeeded to withdraw. your balance is" + this.TotalMoney);
        }
        else if((overdraft < 0)&&(overdraft > -1000))
        {
            this.TotalMoney = overdraft + overdraft * 0.05; // The interest is 5% of the overdraft
            System.out.println("Succeeded to withdraw. your balance is" + this.TotalMoney);
        }
        else
        {
            System.out.println("Failed to withdraw, you can not overdraft more than 1000!");
        }
    }  
}

利用Junit写出的测试代码如下

import static org.junit.Assert.*;

import org.junit.AfterClass;
import org.junit.Test;

public class BankAccountTest {

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
    }

    @Test
    public void BankAccount()
    {
           String AccountNumberTest = new String("1");
           String AccountNameTest = new String("Q");
           String IDTest = new String("QID");
           String PasswordTest = new String("123");
           BankAccount s = new BankAccount(AccountNumberTest, AccountNameTest, IDTest, PasswordTest);
           assertEquals(AccountNumberTest, s.AccountNumber);
           assertEquals(AccountNameTest, s.AccountName);
           assertEquals(IDTest, s.ID);
           assertEquals(PasswordTest, s.Password);
    }
    
    @Test
    public void Balance()
    {
        BankAccount s = new BankAccount("1", "Q", "QID", "123");
        
        s.Balance(s.AccountNumber);
    }
    
    @Test
    public void ExceptionDeposit() 
    {
        BankAccount s = new BankAccount("1", "Q", "QID", "123");
        s.Deposit(-10);
    }
    
    @Test
    public void Deposit()
    {
        BankAccount s = new BankAccount("1", "Q", "QID", "123");
        s.Deposit(10);
    }
    
    @Test
    public void ExceptionWithDraw()
    {
        BankAccount s = new BankAccount("1", "Q", "QID", "123");
        s.TotalMoney = 10;
        s.Withdraw(100); 
    }
    
    @Test
    public void WithDraw()
    {
        BankAccount s = new BankAccount("1", "Q", "QID", "123");
        s.TotalMoney = 100;
        s.Withdraw(10);
    }
}

import static org.junit.Assert.*;

import org.junit.AfterClass;
import org.junit.Test;

public class BankAccountGoldTest {

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
    }

    @Test
    public void BankAccountGold()
    {
        String AccountNumberTest = new String("1");
        String AccountNameTest = new String("Q");
        String IDTest = new String("QID");
        String PasswordTest = new String("123");
        
        BankAccountGold s= new BankAccountGold(AccountNumberTest, AccountNameTest, IDTest, PasswordTest);
        assertEquals(AccountNumberTest, s.AccountNumber);
        assertEquals(AccountNameTest, s.AccountName);
        assertEquals(IDTest, s.ID);
        assertEquals(PasswordTest, s.Password);
    }
    
    @Test
    public void WithDraw()
    {
        BankAccountGold s = new BankAccountGold("1", "Q", "QID", "123");
        s.TotalMoney = 100;
        s.Withdraw(10.0);
        s.TotalMoney = 100;
        s.Withdraw(150, 0);
        s.TotalMoney = 100;
        s.Withdraw(2000, 0);
    }
}

测试结果如下：

2 总结&问题

　　这是我第一次接触自动的单元测试的框架，感觉还是很新奇。Junit在我看来本质就是利用一些assert等的辅助语句实现对软件自动化测试的工具。刚开始还以为测试用例都可以自己生成，接触后才发现还是无法达到这么智能，需要自己进行书写测试用例，只不过把一些之前可能要利用print才能看出结果的语句，利用自动化的图表统计出来。这个实验由于java和Junit都不熟，有个问题在这里记录下，希望之后可以解决。

　　在待测试代码中存在try catch语句时，如何测试代码进入到catch中。这里并不能直接利用Junit4中的expected来检测待测试进入异常。上述实验中是通过观看输出来判定是否到达这个分支，并不能实现自动测试。