Exception Handling in Java - Overview

What is an Exception?

An exception is an event triggering a problem during the execution of a program (runtime).

Exception Hierarchy:

• Throwable is the parent of all exceptons.
• Error: Serious problems (OutOfMemoryError).
• Exception: Conditions that can be caught (IOException, SQLException).

Checked vs Unchecked

Checked Exceptions: Checked at compile-time (e.g. IOException). Must be handled.

Unchecked Exceptions: Runtime Exceptions (e.g. NullPointerException). Not checked at compile-time.