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Top 10 Mistakes in Hibernate and How to Avoid Them (With Examples)
Hibernate is a powerful ORM (Object-Relational Mapping) framework for Java, making database interactions easier. However, many developers make common mistakes that lead to performance issues, inefficient queries, and security risks.
In this guide, we’ll explore the top 10 Hibernate mistakes and provide best practices using Hibernate 6.x (Jakarta Persistence API — JPA 3.1) to avoid them.
For non-members, read this article for free on my blog: Top 10 Mistakes in Hibernate and How to Avoid Them (With Examples)
Let’s dive in! 🏊♂️
1️⃣ Not Managing Transactions Properly
Problem: Many developers assume Hibernate automatically handles transactions. Failing to use transactions properly can cause inconsistent data and unexpected behavior.
❌ Bad Code (No Transaction Handling)
public void saveUser(User user) {
entityManager.persist(user); // No transaction management
}🔴 Issue: Hibernate won’t roll back changes if an error occurs, leading to data corruption.
✅ Good Code (Using @Transactional)
import jakarta.transaction.Transactional;
@Service
public class UserService {
@PersistenceContext
private EntityManager entityManager;
@Transactional
public void saveUser(User user) {
entityManager.persist(user);
}
}✅ Why is this better?
✔ Ensures atomicity (all changes either commit or roll back).
✔ Prevents partial updates that can leave the database in an inconsistent state.
2️⃣ LazyInitializationException — Lazy Loading Gone Wrong
Problem: Hibernate loads related entities lazily by default to optimize performance. But accessing them outside a transaction causes LazyInitializationException.
❌ Bad Code (Accessing Lazy-Loaded Data Outside a Transaction)
User user = userRepository.findById(1L).get();
List<Order> orders = user.getOrders(); // Throws LazyInitializationException🔴 Issue: The orders collection isn't loaded because we're outside a transaction.
