Followed instructions

interfaces-1.iml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.12" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
+  </component>
+</module>

pom.xml

@@ -5,7 +5,19 @@
   <groupId>io.zipcoder</groupId>
   <artifactId>interfaces-1</artifactId>
   <version>0.0.1-SNAPSHOT</version>
-  <packaging>jar</packaging>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>7</source>
+                    <target>7</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <packaging>jar</packaging>
 
   <name>interfaces-1</name>
   <url>http://maven.apache.org</url>

src/main/java/io/zipcoder/interfaces/Educator.java

@@ -0,0 +1,23 @@
+package io.zipcoder.interfaces;
+
+public enum Educator implements Teacher {
+    LEON(1), DOLIO(2), KRIS(3);
+
+    private final Instructor instructor;
+    double timeWorked;
+
+    private Educator(long id) {
+        this.instructor = Instructors.getInstance().findById(id);
+        Instructors.getInstance().add(instructor);
+    }
+
+    public void teach(Learner learner, double numberOfHours) {
+        instructor.teach(learner, numberOfHours);
+        timeWorked += numberOfHours;
+    }
+
+    public void lecture(Learner[] learners, double numberOfHours) {
+        instructor.lecture(learners, numberOfHours);
+        timeWorked += numberOfHours;
+    }
+}

src/main/java/io/zipcoder/interfaces/Instructor.java

@@ -0,0 +1,20 @@
+package io.zipcoder.interfaces;
+
+public class Instructor extends Person implements Teacher {
+
+
+    Instructor(long id, String name) {
+        super(id, name);
+    }
+
+    public void teach(Learner learner, double numberOfHours) {
+        learner.learn(numberOfHours);
+    }
+
+    public void lecture(Learner[] learners, double numberOfHours) {
+        double numberOfHoursPerLearner = numberOfHours / learners.length;
+        for (Learner learner : learners) {
+            learner.learn(numberOfHoursPerLearner);
+        }
+    }
+}

src/main/java/io/zipcoder/interfaces/Instructors.java

@@ -0,0 +1,22 @@
+package io.zipcoder.interfaces;
+
+public class Instructors extends People<Instructor> {
+
+    private static final Instructors INSTANCE = new Instructors();
+
+    private Instructors() {
+        add(new Instructor(1, "Leon"));
+        add(new Instructor(2, "Dolio"));
+        add(new Instructor(3, "Kris"));
+
+    }
+
+    public static Instructors getInstance() {
+        return INSTANCE;
+    }
+
+    @Override
+    public Instructor[] toArray() {
+        return personList.toArray(new Instructor[0]);
+    }
+}

src/main/java/io/zipcoder/interfaces/Learner.java

@@ -0,0 +1,8 @@
+package io.zipcoder.interfaces;
+
+public interface Learner {
+
+    void learn(double numberOfHours);
+
+    Double getTotalStudyTime();
+}

src/main/java/io/zipcoder/interfaces/People.java

@@ -0,0 +1,54 @@
+package io.zipcoder.interfaces;
+
+import java.util.*;
+
+public abstract class People <SomePerson extends Person> implements Iterable<Person> {
+
+    List<SomePerson> personList = new ArrayList<>();
+
+    public void add(SomePerson person) {
+        personList.add(person);
+    }
+
+    public SomePerson findById(long id) {
+        for (SomePerson person : personList) {
+            if (person.getId() == id) {
+                return person;
+            }
+        }
+        return null;
+    }
+
+    public boolean contains(SomePerson person) {
+        for (SomePerson personToLookFor : personList) {
+            if (personToLookFor.getId() == person.getId()
+            && personToLookFor.getName().equals(person.getName())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void remove(SomePerson person) {
+        personList.remove(person);
+    }
+
+    public void remove(long id) {
+        remove(findById(id));
+    }
+
+    public void removeAll() {
+        personList.clear();
+    }
+
+    public int count() {
+        return personList.size();
+    }
+
+    public abstract SomePerson[] toArray();
+
+    public Iterator<Person> iterator() {
+        Iterator iterator = personList.iterator();
+        return iterator;
+    }
+}

src/main/java/io/zipcoder/interfaces/Person.java

@@ -2,4 +2,23 @@
 
 public class Person {
 
+    final long id;
+    String name;
+
+    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/io/zipcoder/interfaces/Student.java

@@ -0,0 +1,18 @@
+package io.zipcoder.interfaces;
+
+public class Student extends Person implements Learner{
+
+    double totalStudyTime;
+
+    Student(long id, String name) {
+        super(id, name);
+    }
+
+    public void learn(double numberOfHours) {
+        totalStudyTime += numberOfHours;
+    }
+
+    public Double getTotalStudyTime() {
+        return totalStudyTime;
+    }
+}

src/main/java/io/zipcoder/interfaces/Students.java

@@ -0,0 +1,36 @@
+package io.zipcoder.interfaces;
+
+public class Students extends People<Student> {
+
+    private static final Students INSTANCE = new Students();
+
+    private Students() {
+        add(new Student(1, "Sitara"));
+        add(new Student(2, "Nicholas"));
+        add(new Student(3, "Denee"));
+        add(new Student(4, "Charnae"));
+        add(new Student(5, "Jennifer"));
+        add(new Student(6, "Nathan"));
+        add(new Student(7, "Zach S"));
+        add(new Student(8, "Jeremy"));
+        add(new Student(9, "Zach K"));
+        add(new Student(10, "Emmanuel"));
+        add(new Student(11, "Bobbi"));
+        add(new Student(12, "Rex"));
+        add(new Student(13, "Nishaben"));
+        add(new Student(14, "Raymond"));
+        add(new Student(15, "Dipinti"));
+        add(new Student(16, "John"));
+        add(new Student(17, "Tatiana"));
+        add(new Student(18, "Laura"));
+    }
+
+    public static Students getInstance() {
+        return INSTANCE;
+    }
+
+    @Override
+    public Student[] toArray() {
+        return personList.toArray(new Student[0]);
+    }
+}

src/main/java/io/zipcoder/interfaces/Teacher.java

@@ -0,0 +1,8 @@
+package io.zipcoder.interfaces;
+
+public interface Teacher {
+
+    void teach(Learner learner, double numberOfHours);
+
+    void lecture(Learner[] learners, double numberOfHours);
+}