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Explanation

What is Optional in Spring Data JPA? 📦 Optional is used to handle null values safely when retrieving data from the database. Instead of returning null, methods like findById() return Optional<T>, helping avoid NullPointerException and making code more readable.

Code:

Optional<User> user = userRepository.
findById(id);

Explanation

Checking if Value Exists using isPresent() ✅ Use isPresent() to check whether the Optional object contains a value before accessing it. This prevents runtime errors.

Code:

Optional<User> user = userRepository.
findById(id);

if(user.isPresent()) {
    System.out.println(user.get().getName());
}

Explanation

Using orElse() for Default Values The orElse() method returns a default value if the Optional object is empty, making code safer and cleaner.

Code:

User user = userRepository.findById(id)
              .orElse(new User());

Explanation

Using orElseThrow() for Exception Handling Use orElseThrow() when data must exist. It throws a custom exception if the value is not found in the database.

Code:

User user = userRepository.findById(id)
              .orElseThrow(() -> 
new RuntimeException("User not found"));