Average in Lambda Expressions in Java 8

package nilpointer.net;

import java.util.ArrayList;
import java.util.List;

public class Demo {

	public static void main(String[] args) {

		List<Integer> numbers = new ArrayList<Integer>();
		numbers.add(5);
		numbers.add(2);
		numbers.add(11);
		numbers.add(-9);
		numbers.add(7);
		numbers.add(-4);

		double avg1 = numbers.stream().mapToInt(p -> p).average().getAsDouble();
		System.out.println("avg 1: " + avg1);

		double avg2 = numbers.stream().filter(p -> p > 0).mapToInt(p -> p).average().getAsDouble();
		System.out.println("avg 2: " + avg2);

	}

}

Output

avg 1: 2.0
avg 2: 6.25