you can also have generic interfaces. Generic interfaces are specified just like generic classes. Here is an example. It creates an interface
called MinMax that declares the methods min( ) and max( ), which are expected to return the minimum and maximum value of some set of objects.

Example

interface MinMax<T extends Comparable<T>> {
	T min();

	T max();
}

// Now, implement MinMax
class MyClass<T extends Comparable<T>> implements MinMax<T> {
	T[] vals;

	MyClass(T[] o) {
		vals = o;
	}

	// Return the minimum value in vals.
	public T min() {
		T v = vals[0];
		for (int i = 1; i < vals.length; i++)
			if (vals[i].compareTo(v) < 0)
				v = vals[i];
		return v;
	}

	// Return the maximum value in vals.
	public T max() {
		T v = vals[0];
		for (int i = 1; i < vals.length; i++)
			if (vals[i].compareTo(v) > 0)
				v = vals[i];
		return v;
	}
}

class GenericInterfaces {
	public static void main(String args[]) {
		Integer inums[] = { 3, 6, 2, 8, 6 };
		Character chs[] = { 'b', 'r', 'p', 'w' };
		MyClass<Integer> iob = new MyClass<Integer>(inums);
		MyClass<Character> cob = new MyClass<Character>(chs);
		System.out.println("Max value in inums: " + iob.max());
		System.out.println("Min value in inums: " + iob.min());
		System.out.println("Max value in chs: " + cob.max());
		System.out.println("Min value in chs: " + cob.min());
	}
}

Output

Inside Base Class
Inside Derived Class