Zeek_83_InheritingExceptionClass.java

 

/*

  (CUSTOM OR USER-DEFINED) EXCEPTIONS

 

 Sometimes in real life(or different scenarios) there are things that are not right

or appropriate but computer has no issues with it.

 

 For example- Age of a person is not negative

              Age of a person is generally not more than 200 years.

             

 So we want computer to treat these circumstances as an Exception.

 

 Therefore we create our own custom Exception Class which inherits features of  Exception Class.

 

 Hence,Exception Class is----------> parent class

       Custom Exception Class is---> child class

       

 Some important methods we can override when we inherit Exception Class:

 

 toString();    -------> return type is String

                         Executed When... System.out.println();...is used

 

 printStackTrace();----> return type is void(i.e-null)

                         prints stack trace.

 

 getMessage();   -------> return type is string

                          prints exception message

                          Executed When... System.out.println();...is used

                         

 Write a code which takes age from user and throws exception if

 --> age is negative or age is more than 200  [i.e (age<0 | age>200)]

 

 Override getMessage() and toString()

 Check what printStackTrace() prints...

 

 */

package com.company;

import java.util.Scanner;

class MyExceptions extends Exception{

@Override

    public String toString() {

        return "Age should be between 0 to 200";

    }

@Override

    public String getMessage() {

        return "Enter realistic age.";

   }

}

public class Zeek_83_InheritingExceptionClass {

    public static void main(String[] args) {

        Scanner sc=new Scanner(System.in);

       

        System.out.println("Enter age:");

        int age=sc.nextInt();

       

    if(age<0 |age>200) {

       

        try {

            throw new MyExceptions();  //Throwing my custom Exception class

        }

        catch(Exception e)

        {

            System.out.println(e.getMessage());

           

            System.out.println(e.toString());

           

            e.printStackTrace();

           

            System.out.println("GoodBye.");

        }

       

    }

   

    System.out.println("The END");

   }

}