first commit without compile error abstract compeleted

org/university/core/AbstractEmployee.java

+package org.university.core;
+
+import java.util.*;
+
+public abstract class AbstractEmployee extends Person{
+    protected ArrayList<Statement> bankStatements;
+
+    protected String position;
+
+    protected Date lastPromote;
+
+    protected double basicIncome;
+
+    public AbstractEmployee(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+        bankStatements = new ArrayList<>();
+        lastPromote = new Date();
+    }
+
+    public String getPosition(){
+        return position;
+    }
+
+    public void addBankStatement(Statement s){
+        bankStatements.add(s);
+    }
+
+    public Statement[] getBankStatements(){
+        Statement[] arr = new Statement[bankStatements.size()];
+        bankStatements.toArray(arr);
+        return arr;
+    }
+
+    public void setBasicIncome(double income){
+        this.basicIncome = income;
+    }
+
+    public boolean promote(){
+        if(isPromotable()){
+            lastPromote = new Date();
+            return true;
+        }
+        return false;
+    }
+
+    abstract public double getCurrentIncome();
+
+    abstract public boolean isPromotable();
+}

org/university/core/Article.java

+package org.university.core;
+
+public class Article{
+    private String name;
+    private int year;
+    
+    public Article(){
+        this.name = name;
+        this.year = year;
+    }
+
+    public String getName(){
+        return name;
+    }
+
+    public int getYear(){
+        return year;
+    }
+}

org/university/core/Course.java

+package org.university.core;
+
+import java.util.ArrayList;
+
+public class Course {
+    private String name;
+    private Professor instructor;
+    private ArrayList<Student> students = new ArrayList<Student>();
+    private GraduateStudent teacherAssistance;
+
+
+    public GraduateStudent getTeacherAssistance() {
+        return teacherAssistance;
+    }
+
+    public void setTeacherAssistance(GraduateStudent teacherAssistance) {
+        this.teacherAssistance = teacherAssistance;
+    }
+
+    public Course(String name, Professor instructor) {
+        this.name = name;
+        this.instructor = instructor;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Professor getInstructor() {
+        return instructor;
+    }
+
+    public ArrayList<Student> getStudents() {
+        return students;
+    }
+
+    public void addStudent(Student student){
+        this.students.add(student);
+    }
+}

org/university/core/Department.java

+package org.university.core;
+
+import java.util.ArrayList;
+
+public class Department {
+    private String name;
+    private ArrayList<Course> courses = new ArrayList<>();
+    public Department(String name){
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public ArrayList<Course> getCourses() {
+        return courses;
+    }
+
+    public void addCourse(Course course){
+        courses.add(course);
+    }
+}

org/university/core/GraduateStudent.java

+package org.university.core;
+
+import java.util.*;
+
+public class GraduateStudent extends Student{
+    private ArrayList<Article> articles;
+
+    public GraduateStudent(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+    }
+
+    public Article[] getArticles(){
+        Article[] arr = new Article[articles.size()];
+
+        articles.toArray(arr);
+        return arr;
+    }
+
+    public void addArticle(Article c){
+        articles.add(c);
+    }
+}

org/university/core/Person.java

+package org.university.core;
+
+public class Person{
+    protected String name;
+    protected int entranceYear;
+    protected int id;
+
+    public Person(String name, int entranceYear, int id){
+        this.name = name;
+        this.entranceYear = entranceYear;
+        this.id = id;
+    }
+
+    public String getName(){
+        return name;
+    }
+
+    public int getEntranceYear(){
+        return entranceYear;
+    }
+
+    public int getId(){
+        return id;
+    }
+}

org/university/core/Professor.java

+package org.university.core;
+
+import java.util.*;
+
+public class Professor extends AbstractEmployee{
+    private ArrayList<Course> courses;
+    private String group;
+
+    public Professor(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+        courses = new ArrayList<>();
+        basicIncome = 7000;
+    }
+
+    public double getCurrentIncome(){
+        return courses.size() * 1000 + basicIncome; 
+    }
+
+    public Course[] getCourses(){
+        Course[] arr = new Course[courses.size()];
+        courses.toArray(arr);
+        
+        return arr;
+    }
+
+    public void addCourse(Course c){
+        courses.add(c);
+    }
+
+    public String getGroup(){
+        return group;
+    }
+
+    public boolean isPromotable(){
+        //TODO
+        return true;
+    }
+}

org/university/core/ServiceEmaployee.java

+package org.university.core;
+
+import java.util.*;
+
+public class ServiceEmaployee extends AbstractEmployee{
+    public int extraWork;
+
+    public ServiceEmaployee(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+        basicIncome = 3;
+    }
+
+    public void setExtraWork(int extraWork){
+        this.extraWork = extraWork;
+    }
+
+    public int getExtraWork(){
+        return extraWork;
+    }
+
+    public double getCurrentIncome(){
+        return extraWork * 500 + basicIncome; 
+    }
+
+    public boolean isPromotable(){
+        long dis = (new Date()).getTime() - lastPromote.getTime();
+        dis /= 1000 * 3600 * 24 * 365;
+
+        return dis >= 3;
+    }
+}

org/university/core/Statement.java

+package org.university.core;
+
+import java.util.*;
+
+public class Statement{
+    private int amount;
+    private Date date;
+    private AbstractEmployee receiver;
+
+    public Statement(int amount, Date date, AbstractEmployee receiver){
+        this.amount = amount;
+        this.date = date;
+        this.receiver = receiver;
+    }
+
+    public int getAmount(){
+        return amount;
+    }
+
+    public Date getDate(){
+        return date;
+    }
+
+    public AbstractEmployee receiver(){
+        return receiver;
+    }
+}

org/university/core/Student.java

+package org.university.core;
+
+import java.util.*;
+
+public class Student extends Person{
+
+    protected String college;
+    protected ArrayList<Course> passedCourses;
+
+    public Student(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+        passedCourses = new ArrayList<>();
+    }
+
+    public String getCollege(){
+        return college;
+    }
+    public Course[] getPassedCourses(){
+        Course[] arr = new Course[passedCourses.size()];
+
+        passedCourses.toArray(arr);
+        return arr;
+    }
+
+    public void addCourse(Course c){
+        passedCourses.add(c);
+    }
+}

org/university/core/UnderGradStudent.java

+package org.university.core;
+
+public class UnderGradStudent extends Student{
+    public UnderGradStudent(String name, int entranceYear, int id){
+        super(name, entranceYear, id);
+    }
+}