Exception

1) can handle all types of exceptions
2) Handles situations the system cannot recover from

The basic way of handling exceptions in Java

First a try block contains all the code that should run and may contain exceptions. When there is an exception, the throw operator is used which sends the code to the catch block, which contains the code for handling the exceptions

the finally block contains all code that should be run whether an exception is thrown or not. It would normally contains processes such as closing files and clearing screens.

Catch blocks should be put in the correct order, from most specific to most general, so that the wrong catch is not done. The catch blocks are examined in the order they are written.

Exceptions must be taken care of by either throwing an exception and catching it with a catch block or declaring an exception and using a throws clause.

A checked exception is any exception that is subject to the Catch or Declare Rule. The compiler will check to make sure they are accounted for. The throwable and exception classes are checked.

Any exceptions not subject to the Catch or Declare Rule. The error and RunTime exception classes are unchecked.

Must be derived from the exception class.
Needs at least two constructors
Must preserve the getMessage method

ArrayIndexOutofBounds
NullPointerException
TypeMismatchException

A throws clause is when an exception is thrown but not caught, so a warning must be given by declaring an exception. It is needed when you do not use a try catch throw block because all exceptions must be accounted for by the Catch or Declare Rule.

In GUI based programs: nothing happens
In non GUI based programs: the program terminates with an error naming the exceptions