Java Tutorial

Exception Handling

Whenever we develop any project in real time it should work in all circumstances (mean in any operation either in error or error free). Every technology or every programming language, if we use for implementing real time applications and if the end user commits a mistake then by default that language or technology displays system error messages which are nothing but run time errors.

Run time errors in JAVA are known as exceptions.

System error messages are those which are unable to understand by end user or client.

User friendly messages are those which are understandable by end user or client.

handling is a mechanism of converting system error messages into user friendly messages.

Errors are of two types. They are compile time errors and run time errors.

Compile time errors are those which are occurring because of poor understanding of the language.

Run time errors are those which are occurring in a program when the user inputs invalid data.

The run time errors must be always converted by the JAVA programmer into user friendly messages by using the concept of exceptional handling.


In JAVA run time environment, to perform any kind of operation or task or an action that will be performed with respect to either class or an interface.

Whenever we pass invalid data as an input to the JAVA program then JAVA run time environment displays an error message, that error message is treated as a class.