使用JUnit进行Java单元测试的最佳实践案例

原创雨点打透心脏的1/2处 2024-09-21 20:33 4阅读 0赞

以下是一个使用JUnit进行Java单元测试的实践案例，我们将测试一个简单的"银行账户"类：

```java
// BankAccount.java
public class BankAccount {
    private double balance;

public BankAccount(double initialBalance) {
        this.balance = initialBalance;
    }

// getters and setters

public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
        }
    }

public void withdraw(double amount) {
        if (amount > 0 && balance >= amount) {
            balance -= amount;
        } else {
            throw new InsufficientFundsException("Insufficient funds for withdrawal.");
        }
    }
}
```

接下来，我们将编写JUnit测试用例来验证BankAccount类的行为：

```java
// BankAccountTest.java
import org.junit.Test;
import static org.junit.Assert.*;

public class BankAccountTest {

@Test
    public void testConstructor() {
        BankAccount account = new BankAccount(100.0);
        assertEquals(100.0, account.getBalance(), 0.01);
    }

@Test
    public void testDeposit() {
        BankAccount account = new BankAccount(100.0);
        account.deposit(50.0);
        assertEquals(150.0, account.getBalance(), 0.01);
    }

@Test(expected = InsufficientFundsException.class)
    public void testWithdrawInsufficient() {
        BankAccount account = new BankAccount(100.0);
        account.withdraw(200.0);
    }

@Test
    public void testWithdraw() {
        BankAccount account = new BankAccount(50.0);
        account.deposit(300.0); // Balance increased to 350.0

account.withdraw(100.0);
        assertEquals(250.0, account.getBalance(), 0.01);

// Testing withdraw without deposit first
        account.withdraw(50.0));
        assertEquals(200.0, account.getBalance(), 0.01);
    }
}
```

这个测试案例包含了BankAccount类的构造器、存款、取款以及异常处理等方面的测试。