Adjustment over excelent tutorial about lambda in java 8: https://blog.idrsolutions.com/2015/02/java-8-method-references-explained-5-minutes/

ReferenceToConstructor.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Function;

public class ReferenceToConstructor {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
         List<Integer> numbers = Arrays.asList(4, 9, 16, 25, 36);
         List<Double> squaredNumbers = ReferenceToConstructor.findSquareRoot(numbers, Double::new);
         System.out.println("Square root of numbers = "+squaredNumbers);
    }
 
    private static List<Double> findSquareRoot(List<Integer> list, Function<Double, Double> f) {
        List<Double> result = new ArrayList<>();
        list.forEach(x -> result.add(f.apply(Math.sqrt(x))));
        return result;
    }
    
}

ReferenceToInstanceMethodAOPT.java

import java.util.ArrayList;
import java.util.List;
import java.util.function.Function;

public class ReferenceToInstanceMethodAOPT {

  /**
   * @param args
   *          the command line arguments
   */

  private static class Person {

    private final String name;
    private final int age;

    public Person(String name, int age) {
      this.name = name;
      this.age = age;

    }

    public String getName() {
      return name;
    }

    public int getAge() {
      return age;
    }

  }

  public static void main(String[] args) {
        // TODO code application logic here
        List<Person> persons = new ArrayList<>();
            persons.add(new Person("Albert", 80));
            persons.add(new Person("Ben", 15));
            persons.add(new Person("Charlote", 20));
            persons.add(new Person("Dean", 6));
            persons.add(new Person("Elaine", 17));
 
 
            List<Integer> allAges = ReferenceToInstanceMethodAOPT.listAllAges(persons, Person::getAge);
            System.out.println("Printing out all ages \n"+allAges);
    }

  private static List<Integer> listAllAges(List<Person> person, Function<Person, Integer> f) {
        List<Integer> result = new ArrayList<>();
        person.forEach(x -> result.add(f.apply(x)));
        return result;
    }
}

ReferenceToStaticMethodExample.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;

public class ReferenceToStaticMethodExample {
     /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16);
        List<Integer> primeNumbers = findPrimeNumbers(numbers, (number) -> isPrime((int) number));
 
        System.out.println("Prime Numbers are " + primeNumbers);
    }
 
    public static boolean isPrime(int number) {
        if (number == 1) {
            return false;
        }
        for (int i = 2; i < number; i++) {             
            if (number % i == 0) {                 
                return false;             
            }         }         
        return true;     
    }     
 
    public static <T> List<T> findPrimeNumbers(List<T> list, Predicate<T> predicate) {         
        List<T> sortedNumbers = new ArrayList<>();  
        list.stream()
          .filter(i -> predicate.test(i))
          .forEach(i -> sortedNumbers.add(i));
        return sortedNumbers;
 
    }
}