This document summarizes key concepts about exceptions in Java. It defines an exception as a runtime error caused by logical mistakes during program execution. When an exception occurs, an exception object is created containing error details and program state. By default, Java prints the exception description and stack trace. Exceptions are classified as either checked or unchecked. Keywords for handling exceptions include try, catch, finally, throws, and throw. Methods like printStackTrace(), toString(), and getMessage() can output exception details.

1. Submitted to :-
Mr.r.s.s.rawat
(H.O.D. of it department)
Submitted by:-
Satish ahirwar
B.e. VIIth sem
enroll no.:-0601it131046

3. Contents
What is an Exception .
What happen when an Exception is occurs.
Runtime Error.
Exception class Hierarchy.
Types of Exception.
Exception Handling Keywords.
Methods for printing the details of an
Exception.

4. What is an Exception?
In general, Exception are run time errors caused
due to logical mistakes occurred during program
execution because of its wroung input.
Examples:-
ArithmaticException.
ArrayOutOfBoundException.
IOException.
FileNotFoundException.
SQLException.
etc.

5. Exception Example
(ArithmeticException)
1 class DivByZero {
2
3
public static void main(String args[]) {
System.out.println(3/0);
4 System.out.println(“Pls. print me.”);
5 }
6 }

6. What Happens When an Exception
Occurs?
When an exception occurs within a method, the
method creates an exception object and hands it off
to the runtime system.
Exception object contains information about the error,
including its type and the state of the program when the
error occurred.

7. Example: Default Exception Handling
 Displays this error message
Exception in thread "main"
java.lang.ArithmeticException: / by zero
at DivByZero.main(DivByZero.java:3)
 Default exception handler
–
–
–
Provided by Java runtime
Prints out exception description
Prints the stack trace

8. Runtime Error
It is also unwanted unexpected problem .
A run time error is occurs due to the system
resource problem for run time error it is not
possible to provide the solution
programmatically.
Examples:-
StackOverFlowError
OutOfMemoryError
Etc.

9. Exception class Hierarchy

10. Types Of Exception
In java there are two types of exception .
 Checked Exception-the checked Exceptions
are recognised by compiler.
 Unchecked Exception.- The Unchecked
Exceptions are not recognised by comiler.

11. Checked Exception

12. Unchecked Exception
ERROR
OutOfMemoryError
StackOverFlowError
etc,.

13. Exception Handling Keywords
try
catch
finally
throws
throw

14. syntax
try
{ // Risky Code
}
catch(type of exception-1 object-1)
{ // Handling Code
}
catch(type of exception-2 object-2)
{ // Handling Code
}
finally
{ // Resource releasing logic.
}

15. throw Keyword
●
●
Java allows you to throw exceptions (generate
exceptions)
throw <exception object>;
An exception you throw is an object
–
●
You have to create an exception object in the same way
you create any other object
Example:
throw new ArithmeticException(“testing...”);

16. throws Keyword
●
Throws is a java Keyword use to by paas
generated exception from present method to
calling methods.
Syntax
Methodname() throws <Exceptionobject>
{
//throw Exception object
}

17. Methods for printing the details
of an Exception.
In java there are three methods for Printing the details of an Exception
• Public void PrintstackTrace()
{name of the Exception: Discription of the Exception:Location of the Exception}
• Public String toString ()
{Name of the Exception :Discription of the Exception.}
• Public String getmessage()
{Discription of the Exception}

20. 60
Thank You!