Effective Java 3/E summary chanpter 9 (Shorter version)

05 Apr 2021

Chanpter 9 : Exceptions

You can find the longer version of this summary here.

When to use?

• Exception situation other than control flow (normal API should not use Exception)
• If Exception occurs, that is, the client needs to recover, use checked exception.
• Use runtime exceptions for Programming errors.

Standard exceptions

IllegalArgumentException : Argument is invalid IllegalStateException : Object state is inappropriate for method execution ConcurrentModificationException : Single threaded design accessed by multiple threads UnsupportedOperationException : When calling an unavailable method NullPointerException : If null is not allowed, but null is entered IndexOutOfBoundsException : When the index range is exceeded

Better exception

• If low-level exceptions are widespread, high-level exceptions are used.
• If you want to show low-level exceptions, use exception chaining.
• If it is difficult to provide information due to exception, use logging.
• Documentation.
• Include failure information in detail messages.
• Maintains the state of the object even if an exception occurs.