Solution for Lambdas 02

Exercise.java

@@ -4,14 +4,14 @@ public static void main(String[] args) {
     Student steffen = new Student("Steffen", 28);
     Student kid = new Student("Kind", 15);
 
-    FilteredAdultStudents adultStudents = new FilteredAdultStudents();
+    FilteredStudents adultStudents = new FilteredStudents((student) -> student.age > 18);
     adultStudents.add(steffen);
     adultStudents.add(kid);
     adultStudents.printStudents();
 
     System.out.println("-----------------------");
 
-    FilteredTeenStudents teenStudents = new FilteredTeenStudents();
+    FilteredStudents teenStudents = new FilteredStudents(student -> student.age < 18);
     teenStudents.add(steffen);
     teenStudents.add(kid);
     teenStudents.printStudents();

FilteredStudents.java

@@ -0,0 +1,22 @@
+import java.util.ArrayList;
+import java.util.function.Predicate;
+
+public class FilteredStudents {
+  private ArrayList<Student> students;
+  private Predicate<Student> mandatoryFilter;
+
+  public FilteredStudents(Predicate<Student> filter) {
+    this.students = new ArrayList<>();
+    this.mandatoryFilter = filter;
+  }
+
+  public void add(Student element) {
+    if (this.mandatoryFilter.test(element)) {
+      this.students.add(element);
+    }
+  }
+
+  public void printStudents() {
+    this.students.forEach((student) -> System.out.println(student));
+  }
+}