maven learner lab from ghassan nasr

src/main/java/com/github/curriculeon/Classroom.java

@@ -0,0 +1,30 @@
+package com.github.curriculeon;
+
+import java.util.Map;
+import java.util.HashMap;
+
+public enum Classroom {
+
+    INSTANCE;
+    private Students students = Students.getINSTANCE();
+    private Instructors instructors = Instructors.getINSTANCE();
+
+    public void hostLecture(Teacher teacher, Double numberOfHours) {
+        teacher.lecture(students.getArray(), numberOfHours);
+    }
+
+    public void hostLecture(long id, Double numberOfHours) {
+        Person instructor = instructors.findById(id);
+        Person[] studentArray = new Student[students.count()];
+        students.personList.toArray(studentArray);
+        ((Teacher)instructor).lecture((Learner[])studentArray, numberOfHours);
+    }
+
+    public Map<Student, Double> getStudyMap() {
+        Map<Student, Double> studentMap = new HashMap<>();
+        for(Student student: students.getArray()) {
+            studentMap.put(student, student.getTotalStudyTime());
+        }
+        return studentMap;
+    }
+}

src/main/java/com/github/curriculeon/Instructor.java

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+package com.github.curriculeon;
+
+public class Instructor extends Person implements Teacher {
+
+    public Instructor() {
+    }
+
+    public Instructor(long id, String name) {
+        super(id, name);
+    }
+
+    @Override
+    public void teach(Learner learner, Double numberOfHours) {
+        learner.learn(numberOfHours);
+    }
+
+    @Override
+    public void lecture(Learner[] learners, Double numberOfHours) {
+        Double numberOfHoursLearned = numberOfHours / learners.length;
+
+        for (int i = 0; i < learners.length; i++) {
+            this.teach(learners[i], numberOfHoursLearned);
+        }
+
+    }
+}

src/main/java/com/github/curriculeon/Instructors.java

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+package com.github.curriculeon;
+
+import java.util.List;
+
+public class Instructors extends People<Instructor> {
+
+    private static Instructors INSTANCE;
+
+    private Instructors() {}
+
+    public static Instructors getINSTANCE() {
+        if(INSTANCE == null) { //lazy loading, as opposed to eager loading
+            INSTANCE = new Instructors();
+            INSTANCE.add(new Instructor(444, "Lincoln Barnes"));
+        }
+        return INSTANCE;
+    }
+
+    public Instructor[] getArray() {
+        int sizeOfArray = count();
+        Instructor[] destinationArray = new Instructor[sizeOfArray];
+        List<Instructor> sourceList = personList;
+        return sourceList.toArray(destinationArray);
+    }
+
+}
+

src/main/java/com/github/curriculeon/Learner.java

@@ -0,0 +1,9 @@
+package com.github.curriculeon;
+
+public interface Learner {
+
+    public void learn(Double numberOfHours);
+
+    public Double getTotalStudyTime();
+
+}

src/main/java/com/github/curriculeon/People.java

@@ -0,0 +1,59 @@
+package com.github.curriculeon;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+import java.lang.Iterable;
+
+public abstract class People <E extends Person> implements Iterable<E> {
+
+    List<E> personList;
+
+    public People() {
+        this(new ArrayList<>());
+    }
+
+    public People(List<E> personList) {
+        this.personList = personList;
+    }
+    public void add(E person) {
+        this.personList.add(person);
+    }
+
+    public E findById(long id) {
+        for(E person: personList) {
+            if(person.getId() == id) {
+                return person;
+            }
+        }
+        return null;
+    }
+
+    public Boolean contains(E person) {
+        return personList.contains(person);
+    }
+
+    public void remove(E person) {
+        personList.remove(person);
+    }
+
+    public void removeAll() {
+        personList.clear();
+    }
+
+    public int count() {
+        return personList.size();
+    }
+
+    public abstract E[] getArray();
+
+    @Override
+    public Iterator<E> iterator() {
+        return personList.listIterator();
+        //return new PersonIterator<Person>(personList.iterator());
+    }
+
+
+
+}

src/main/java/com/github/curriculeon/Person.java

@@ -2,4 +2,29 @@
 
 public class Person {
 
+    private final long id;
+    private String name;
+
+    public Person() {
+        this.id = Long.MIN_VALUE;
+        this.name = "";
+    }
+
+    public Person(Long id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
 }
+

src/main/java/com/github/curriculeon/Student.java

@@ -0,0 +1,31 @@
+package com.github.curriculeon;
+
+public class Student extends Person implements Learner {
+
+    private Double totalStudyTime;
+
+    public Student() {
+        super();
+        this.totalStudyTime = 0D;
+    }
+
+    public Student(long id, String name, Double totalStudyTime) {
+        super(id, name);
+        this.totalStudyTime = totalStudyTime;
+    }
+
+    public Student(Double totalStudyTime) {
+        super();
+        this.totalStudyTime = totalStudyTime;
+    }
+
+    @Override
+    public void learn(Double numberOfHours) {
+        this.totalStudyTime += numberOfHours;
+    }
+
+    @Override
+    public Double getTotalStudyTime() {
+        return totalStudyTime;
+    }
+}

src/main/java/com/github/curriculeon/Students.java

@@ -0,0 +1,27 @@
+package com.github.curriculeon;
+
+import java.util.List;
+
+public class Students extends People<Student> {
+
+    private static Students INSTANCE = new Students();
+
+    private Students() {
+        super();
+        this.add(new Student(555, "Molly Fisher", 0D));
+        this.add(new Student(777, "Holly Becker", 0D));
+        this.add(new Student(999, "Brad Singer", 0D));
+    }
+
+    public static Students getINSTANCE() {
+        return INSTANCE;
+    }
+
+    public Student[] getArray() {
+        int sizeOfArray = count();
+        Student[] destinationArray = new Student[sizeOfArray];
+        List<Student> sourceList = personList;
+        return sourceList.toArray(destinationArray);
+    }
+
+}

src/main/java/com/github/curriculeon/Teacher.java

@@ -0,0 +1,8 @@
+package com.github.curriculeon;
+
+public interface Teacher {
+
+    public void teach(Learner learner, Double numberOfHours);
+    public void lecture(Learner[] learners, Double numberOfHourss);
+
+}

src/test/java/com/github/curriculeon/ClassroomTest.java

@@ -0,0 +1,36 @@
+package com.github.curriculeon;
+
+import org.junit.Test;
+import org.junit.Assert;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+
+public class ClassroomTest {
+
+    @Test
+    public void testHostLecture1() {
+        Classroom classroom = Classroom.INSTANCE;
+        Teacher teacher = Instructors.getINSTANCE().findById(444L);
+        Integer numberOfStudents = Students.getINSTANCE().count();
+        Double numberOfHoursToLecture = numberOfStudents.doubleValue();
+        Double expectedNumberOfHoursLearned = numberOfHoursToLecture / numberOfStudents;
+        Map<Student, Double> preStudyMap = classroom.getStudyMap();
+
+        // when
+        classroom.hostLecture(teacher, numberOfHoursToLecture);
+        Map<Student, Double> postStudyMap = classroom.getStudyMap();
+        Set<Student> keySet = postStudyMap.keySet();
+        for (Student student : keySet) {
+            Double preStudyTime = preStudyMap.get(student);
+            Double expectedStudyTime = preStudyTime + expectedNumberOfHoursLearned;
+            Double actualStudyTime = postStudyMap.get(student);
+
+            // then
+            Assert.assertEquals(expectedStudyTime, actualStudyTime);
+        }
+    }
+}

src/test/java/com/github/curriculeon/InstructorTest.java

@@ -0,0 +1,71 @@
+package com.github.curriculeon;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class InstructorTest {
+
+    @Test
+    public void testInstance() {
+        //Given
+        Person teacher;
+
+        //When
+        teacher = new Instructor();
+
+        //Then
+        Assert.assertTrue(teacher instanceof Person);
+    }
+
+    @Test
+    public void testImplementation() {
+        //Given
+        Teacher teacher;
+
+        //When
+        teacher = new Instructor();
+
+        //Then
+        Assert.assertTrue(teacher instanceof Teacher);
+    }
+
+    @Test
+    public void testLecture() {
+
+        //Given
+        Learner learner1 = new Student(5D);
+        Learner learner2 = new Student();
+        Learner learner3 = new Student(6D);
+        Learner[] learners = { learner1, learner2, learner3 };
+        Double[] expectedTotalStudyTimes = { 7D, 2D, 8D };
+
+        //When
+        Instructor instructor = new Instructor();
+        instructor.lecture(learners, 6D);
+        Double[] actualTotalStudyTimes = new Double[3];
+        for (int i = 0; i < learners.length; i++) {
+            actualTotalStudyTimes[i] = learners[i].getTotalStudyTime();
+        }
+
+        //Then
+        Assert.assertArrayEquals(expectedTotalStudyTimes, actualTotalStudyTimes);
+    }
+
+    @Test
+    public void testTeach() {
+        //Given
+        Learner learner = new Student(5D);
+        Teacher teacher = new Instructor();
+
+        //When
+        teacher.teach(learner, 6D);
+        Double actualTotalStudentStudyTime = learner.getTotalStudyTime();
+
+
+        //Then
+        Double expectedTotalStudentStudyTime = 5D + 6D;
+        Assert.assertEquals(expectedTotalStudentStudyTime, actualTotalStudentStudyTime);
+    }
+
+
+}

src/test/java/com/github/curriculeon/InstructorsTest.java

@@ -0,0 +1,27 @@
+package com.github.curriculeon;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class InstructorsTest {
+
+    @Test
+    public void test() {
+        //given
+        // current instructors
+
+        //given
+        // current cohort
+
+        String expectedInstructorName1 = "Lincoln Barnes";
+
+        //when
+        Instructors instructors = Instructors.getINSTANCE();
+
+        String actualInstructorName1 = instructors.findById(444).getName();
+
+        //then
+        Assert.assertEquals(expectedInstructorName1, actualInstructorName1);
+    }
+
+}