Java Exception Codes

ArithmeticException:

• This exception class is belongs to lang package.
• It occurs when we divide any number with zero value.

import java.util.Scanner ;
class ExceptionDemo 
{
    	public static void main(String[] args) 
    	{
        		int a,b,c;
        		System.out.println("Enter two integers :");
        		Scanner sc = new Scanner(System.in);
        		a = sc.nextInt();
        		b = sc.nextInt();
        		c = a/b;
        		System.out.println("Result : "+c);
       	 	System.out.println("Continue.....");
    	}
}

InputMismatchException:

• This exception class is belongs the java.util  package
• Scanner class is used to read input from the user.
• Above exception raised when it read invalid input from the user.

import java.util.Scanner;
class Test 
{
	public static void main(String[] args) 
	{
		Scanner scan = new Scanner(System.in);
		System.out.println(“Enter 2 numbers : “);
		int a = scan.nextInt();
		int b = scan.nextInt();
		int c = a+b;
		System.out.println(“Sum : “ + c);
	}
}

NumberFormatException:

• This exception class is belongs to lang package.
• This will occur when we perform invalid data conversions.

class Test
{
    	public static void main(String[] args)
        {
		String s = "java";
		byte b = Byte.parseByte(s); //Exception : Invalid data conversion
	}
}

ArrayIndexOutOfBoundsException: Occurs while accessing an element which is out of bounds.

class Test 
{
	public static void main(String[] args) 
	{
		int arr[ ] = {10,20,30,40,50};

		int len = arr.length;
		System.out.println("Length is : " + len);
		System.out.println("Last element : " + arr[len-1]);
		System.out.println("Out of array : " + arr[len]);
	}
}

NullPointerException: Occurs while accessing the functionality of object with Null pointer.

class ExceptionDemo 
{
	static ExceptionDemo obj1 = new ExceptionDemo();
	static ExceptionDemo obj2 ;
    	public static void main(String[] args) 
    	{
		obj1.test();	
		obj2.test(); // Exception : Accessing Object functionality using NULL pointer
    	}	
	void test(){
		System.out.println("Testing.....");
	}
}