Java

Explain the differences between HashMap and HashSet data structures.

Junior — Middle

Astonайтеко

How to add constraints to a database?

What do you know about the RandomAccessFile class?

What does 'sleeping' a thread mean in Java?

How can dependent related objects be processed when fetching data from the database?

Junior — Middle

СБЕР

What design patterns do you know?

Can the implementation of a static method in a subclass be changed by overriding it?

Tell us about your knowledge and experience working with Java.

What methods can be used to obtain a new instance of a component configured with the prototype pattern in Spring or similar frameworks?

What factors are affected by using CGLib when dynamically creating proxy objects?

Junior — Middle

СБЕР Корпус

Can you explain the concept of contract testing and its role in microservices integration?

Junior — Middle

Газпромбанк

How to call a static method of an interface?

What are access modifiers in Java and what are they?

Where exactly in memory is the reference located if the variable is a reference type?

On which platform was your last project built?

Junior — Middle

СБЕР

What is the role of stereotype annotations in the Spring framework and why are they used?

Were REST API principles applied in your last project?

Junior — Middle

Газпромбанк

public class MoneyTransferService { /** * @param fromAccountId unique identifier of the user transferring funds * @param toAccountId unique identifier of the user receiving funds * @param amount transfer amount. Positive number */ @Transactional public void transferMoney(Long fromAccountId, Long toAccountId, BigDecimal amount) { if (amount.compareTo(BigDecimal.ZERO) <= 0) { throw new RuntimeException("Amount must be +"); } if (fromAccountId.equals(toAccountId)) { throw new RuntimeException("Account can't be the same"); } Long firstId = Math.min(fromAccountId, toAccountId); Long secondId = Math.max(fromAccountId, toAccountId); Account first = accountRepository.findByIdForUpdate(firstId) .orElseThrow(() -> new RuntimeException("Account not found")); Account second = accountRepository.findByIdForUpdate(secondId) .orElseThrow(() -> new RuntimeException("Account not found")); Account from = fromAccountId.equals(firstId) ? first : second; Account to = fromAccountId.equals(firstId) ? second : first; if (from.getBalance().compareTo(amount) < 0) { throw new RuntimeException("Balance is less 0"); } from.setBalance(from.getBalance().subtract(amount)); to.setBalance(from.getBalance().add(amount)); accountRepository.save(to); accountRepository.save(from); } } @Entity @Data public class Account { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private BigDecimal balance; }

Senior

ОТП Банк

Can you name the main memory areas used within the JVM?

Junior — Middle

IT OneИннотехСБЕР

How can you temporarily disable the execution of tests during a Maven project build?