Exceptions are used for handing errors and other
exceptional events in Java programming language.
Exceptions are abnormal
or special conditions that occurs during execution. Two types of exceptions are
Checked Exceptions: All exceptions exceptions
except RuntimeException and its subclasses are known as Checked Exceptions.
Checked Exceptions are also known as Compile time Exceptions. Checked Exceptions forces programmers to
explicitly handle or to throw the exceptions.
Unchecked Exceptions: RuntimeExceptions or any of its
subclasses are known as unchecked exceptions. Error class and all its subclasses
are also comes under the category of unchecked exceptions. For unchecked exceptions,
compiler doesn't force the programmers to either catch the exception or declare
it in a throws clause.
Handling Exceptions: Keywords try, catch,
throw, throws and finally are used to hand the exceptions
try: try block encapsulate the code that may
catch: catch block handle the exceptions occurred
by the code that exist in the try block or exception may be further forward
to handle later.
throw: this keyword is used to explicitly
throw an exception.
throws: this keyword defines the list of
exception that a certain block of code encapsulated in the try block may
finally: finally block encapsulate the code
that must be executed in every condition regardless an exception is occurred
or not. e.g. example code for closing an file.