Spring Boot Jpa Persistence

In this tutorial, you'll learn about Fix Spring Boot JPA Persistence Context Not Flushing. We cover key concepts, practical examples, and best practices.

The Problem

Entity changes are not written to the database after calling save() or merge().

Quick Fix

Call save() and flush()

Wrong:

@Autowired ProductRepo repo;
repo.save(product);
// Not flushed yet

Output:

Not persisted

Right:

repo.saveAndFlush(product);
// or repo.flush() after save

Output:

Immediately persisted

Use @Transactional

Wrong:

// No transaction
repo.save(product);

Output:

No transaction

Right:

@Transactional
public void saveProduct(Product p) {
    repo.save(p);
}
// Auto-flush on commit

Output:

Flushed on transaction commit

Check transaction boundaries

Wrong:

service.saveProduct(product);
// Same EntityManager may have stale data

Output:

Detached entity

Right:

@Transactional
public void saveProduct(Product p) {
    Product managed = repo.findById(p.getId()).orElse(null);
    if (managed != null) {
        managed.setName(p.getName()); // Merge changes
    }
}

Output:

Managed entity updated

Prevention

• Use saveAndFlush() for immediate persistence
• Wrap operations in @Transactional
• Work with managed entities within the transaction

Common Mistakes with boot jpa persistence

1. Non-exhaustive pattern matches that compile with warnings then crash at runtime
2. Misunderstanding that String is [Char] with poor performance for large text operations
3. Using foldl instead of foldl' causing stack overflow on large lists

These mistakes appear frequently in real-world SPRING code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ

This quick fix is part of the DodaTech Spring & JVM ecosystem series. Built by the developers of Doda Browser, DodaZIP, and Durga Antivirus Pro.