StackNexus Interview Questions and Answers

Abstract class is a class that cannot be instantiated and Interface is a blueprint of a class.

• Abstract class can have both abstract and non-abstract methods while Interface can only have abstract methods.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract class can have constructors while Interface cannot.

• Example of Abstract class: Animal (abstract method: makeSound())

• Example

A singleton class is a class that can only have one instance created at a time.

• Singleton classes are often used in situations where there should only be one instance of a class, such as a database connection or a configuration manager.

• The class typically has a private constructor to prevent multiple instances from being created.

• The instance of the class is usually accessed through a static method or property.

• Example: J...read more

Transactional in Hibernate refers to the management of database transactions.

• Hibernate provides transaction management through the use of the Transaction interface.

• Transactions can be managed programmatically or declaratively using annotations.

• Transactional behavior can be customized using isolation levels and propagation settings.

• Example: @Transactional annotation can be used to mark a method as transactional.

• Example:...read more