java - 如果服务无法实现，应该返回什么

Question

假设我有一个方法可以将一些钱从一个用户转移到另一个用户，但是如果当前余额小于用户想要转移的金额，则应该无法转移。应该返回什么来表明交易是否成功执行。执行此操作的正确方法是什么？

服务等级

@Service
public class TransactionService {
    public TransactionService(){

    }
    public void transferBalanceToAccount(Account senderAccount, Account receiverAccount,Long transferBalance){   
        if(senderAccount != null && receiverAccount != null){
            // get both account balance
            Long senderCurrentBalance = senderAccount.getBalance();
            Long receiverCurrentBalance = receiverAccount.getBalance();

            if(senderCurrentBalance < transferBalance) {
                // i have no idea what to do
                return;
            }

            senderAccount.setBalance(senderCurrentBalance - transferBalance);
            receiverAccount.setBalance(receiverCurrentBalance + transferBalance);
        }
    }
}

单元测试

@Test
    public void transferBalanceToAccountShouldNotBeAbleToTransfer(){
        // Arrange
        Account sender = new Account();
        sender.setBalance(0L);
        Account receiver = new Account();
        receiver.setBalance(100L);

        // Act
        transactionService.transferBalanceToAccount(sender, receiver, 10L);

        // Assert
        // I'm struggling
        assertEquals();
    }

Answer 1

您应该抛出一个自定义异常，例如InsufficientFundsException，并根据您的需要进行处理。在测试中，您可以通过例如检查异常更改注释。在 JUnit 中:
@Test(expected = InsufficientFundsException.class)