Java Auto boxing and Unboxing

public class AutoboxingUnboxing {

	public static void main(String[] args) {
		
		int a=10;
		Integer obj = Integer.valueOf(a);  //boxing
		Integer obj1=a;//auto boxing
		Integer obj2=20;//auto boxing
		
		System.out.println(obj +" "+ obj1 +" "+obj2);
		
		
		int b = obj.intValue();//unboxing
		int c = obj1;//auto unboxing
		System.out.println(b+""+c);
	}
}