Java Exception Handling

/ * 

Create a class Student with attributes roll no, name, age and course. Initialize values through parameterized constructor. If age of student is not in between 15 and 21 then generate user-defined exception “AgeNotWithinRangeException”. If name contains numbers or special symbols raise exception “NameNotValidException”. Define the two exception classes.

*/

import java.lang.Exception;

class AgeNotWithinRange extends Exception{

String msg; AgeNotWithinRange(String m) { 

this.msg = m; 

}

public String toString(){ 

return this.getClass().getName()+":"+msg;

}

}

class NameNotValidException extends Exception{

String msg; NameNotValidException(String m) { 

this.msg = m; 

}

public String toString(){ 

return this.getClass().getName()+":"+msg;

}

}

class Student{

 int rollno;

int age;

String name;

String course;

Student(int r,String n, int a, String c) throws AgeNotWithinRange,NameNotValidException{ 

if(a < 15 || a > 21){  

throw new AgeNotWithinRange(String.valueOf(a)); 

} 

for(int i = 0;i < n.length();i++){  

if(!(Character.isLetter(n.charAt(i)))){      

throw new NameNotValidException(String.valueOf(i));  

} 

} 

this.rollno = r; 

this.name = n; 

this.age = a;

this.course = c; 

System.out.println("Object Created successfully.");

}

 public static void main(String args[]){

 try{   

Student s1 = new Student(Integer.parseInt(args[0]),args[1],Integer.parseInt(args[2]),args[3]);
          }

catch(AgeNotWithinRange abc){ 

System.out.println(abc);  

}

catch(NameNotValidException def){ 

System.out.println(def);  

}

finally{  

System.out.println("Congratulation now you are UG.");

}

 try{   

Student s2 = new Student(Integer.parseInt(args[4]),args[5],Integer.parseInt(args[6]),args[7]);
 }

catch(AgeNotWithinRange abc){ 

System.out.println(abc);  

}

catch(NameNotValidException def){ 

System.out.println(def);  

}

finally{  

System.out.println("Congratulation now you are PG.");

} 

}

}

Developed at : MCA - 3 (A), Department of MCA, B H Gardi College, Rajkot

Example of Multiple Inheritance in JAVA

abstract class A

{

            {

            System.out.println("Abstract Class Object is Created");

            }

           

abstract void display();

}

interface T

{

int i=10;

void print();

}

class B extends A implements T

{

void display()

            {

            System.out.println("Display from Derived Class");

            }

public void print()

            {

            System.out.println("Interface Implementation");

            }

public static void main(String s[])

            {

            B b=new B();

            b.display();

            b.print();

            System.out.println(T.i);

            }

}