What is the difference between checked and unchecked exceptions?

What is the difference between checked and unchecked exceptions?

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	Checked exception	Unchecked exception
예외 발생	컴파일시 예외 catch부에서 처리	런타임 도중 발생하는 catch되지 않은 예외
예외 처리	예외처리 필수	예외처리 필수 아님
트랜잭션 처리	롤백하지 않음	롤백함
예시	IOException, SQLException, ClassNotFoundException, InvocationTargetException	NullPointerException, IndexOutOfBoundsException, IllegalArgumentException, NumberFormatException

Why does Spring prefer unchecked exceptions?

• Checked exceptions reqires handling, result in cluttered code and unnecessary coupling.
• Unchecked exceptions are non-recoverable exceptions, should not let developer to handle. E.g., when happens, nothing you can do.SQLException

  https://mossgreen.github.io/Spring-Certification-Spring-Data-Management/

What is the Spring data access exception hierarchy?

• Data Access Exception is a Runtime Exception
• Examples of concrete Data Access Exceptions
  • CannotAcquireLockException
  • CannotCreateRecordException
  • DataIntegrityViolationException
• Purpose of this hierarchy is to create abstraction layer on top of Data Access APIs to avoid coupling with concrete implementation of Data Access APIs

Spring Professional Exam Tutorial v5.0 - Dominik Cebula