Java 8 - Lambda Expresison

PredicateExample.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;
//www . ja va  2  s .c om
public class Main {
   public static void main(String[] args) {
      List<Student> employees = Arrays.asList(
            new Student(1, 3, "John"),
            new Student(2, 3, "Jane"),
            new Student(3, 4, "Jack")
      );

      // with predicate
      System.out.println(findStudents(employees, createCustomPredicateWith(10_000)));

      // with function definition, both are same
      Function<Double, Predicate<Student>> customFunction = threshold -> (e -> e.gpa > threshold);
      System.out.println(findStudents(employees, customFunction.apply(10_000D)));
   }

   private static Predicate<Student> createCustomPredicateWith(double threshold) {
      return e -> e.gpa > threshold;
   }

   private static List<Student> findStudents(List<Student> employees, Predicate<Student> condition) {
      List<Student> result = new ArrayList<>();

      for (Student e : employees) {
         if (condition.test(e)) {
            result.add(e);
         }
      }

      return result;
   }

}
class Student {
      public int id;
      public long gpa;
      public String name;

      Student(int id, long g, String name) {
         this.id = id;
         this.gpa = g;
         this.name = name;
      }

      @Override
      public String toString() {
         return id + ">" + name + ": " + gpa;
      }
   }