Checked or Unchecked Exceptions in Java: When Should You Use Which?

Choosing Between Checked and Unchecked Exceptions

When authoring custom exception classes in Java, a crucial decision arises: selecting whether to use checked or unchecked exceptions. This choice hinges on the recoverability and predictability of the exception.

Checked Exceptions:

Checked exceptions are advisable when:

• Predictability: The exception occurs due to inevitable conditions beyond the caller's control, such as missing files.
• Recoverability: The exception can be reasonably handled by the caller, enabling them to take appropriate actions, such as providing alternative resources.

Unchecked Exceptions:

Unchecked exceptions are suitable for:

• Unpredictability: The exception occurs due to internal errors or unexpected conditions caused by the application's logic.
• Inadvisability of enforced handling: Enforcing handling of such exceptions hinders flexibility, as the caller cannot always recover from them meaningfully.

Reevaluation and Abstraction:

Evaluate the exception's appropriateness at each invocation level. If the caller can reasonably handle the exception, consider throwing a checked exception. Otherwise, wrap the exception in an unchecked one.

Maintain a proper abstraction level in exceptions. For instance, in a repository implementation with both database and filesystem backends, use a generic exception (e.g., RepositoryException) to avoid exposing implementation details.

Remember to carefully assess the exception's characteristics when choosing between checked and unchecked types. This ensures that exceptions facilitate error handling and application resilience effectively.

The above is the detailed content of Checked or Unchecked Exceptions in Java: When Should You Use Which?. For more information, please follow other related articles on the PHP Chinese website!