Bounded type with Generics

Bounded type parameters allow you to set restrictions on generic type arguments

Declare a bounded type parameter

syntax

T can only be replaced with super class Name or it's subclass ,For Example: This class only accepts type parameters as any class which extends class M or class M itself. Passing any other type will cause compiler time error restricted to only type of M class or it's sub class

class Bound <T extends M>
{
    private T objRefreence;
    public Bound(T objRef){
        this.objRefreence = objRef;
    } 

    public void testMethod(){
        this.objRefreence.showClass();

    }
}

class M {
    public void showClass(){
        System.out.println("inside super class M Class ");
    }
}
class M1 extends M{
    public void showClass(){
        System.out.println("inside sub class M1 Class ");
    }
}
class M2 extends M{
    public void showClass(){
        System.out.println("inside sub class M2 Class ");
    }
}

public class Program2
 {
    public static void main(String[] args) {
        /*create an object of subclass M2 and passing it to bound as a type parameter */
        Bound<M2> b2 = new Bound<M2>(new M2());
        b2.testMethod(); // inside sub class M2 Class

        /*passing super class M */
        Bound<M> b = new Bound<M> (new M());
        b.testMethod();  // inside super class M Class 

        /* passing sub class M1 */
        Bound<M1> b1 = new Bound<M1>(new M1());
        b1.testMethod(); // inside sub class M1 Class
    }
}