Exceptions in java

Exception: Exceptions are abnormal or special conditions that occurs during execution. Two types of exceptions are there.

1. 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.
2. 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 in java.

• try: try block encapsulate the code that may throw exception.
• 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 throw.
• 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.