First finished draft of database model

src/BachelorDegree.java

-public enum BachelorDegree
-{
-    BACHELOR_OF_SCIENCE,
-    BACHELOR_OF_ENGINEERING;
-}

src/BachelorSemester.java

-public enum BachelorSemester
-{
-    FIRST,
-    SECOND,
-    THIRD,
-    FOURTH,
-    FIFTH,
-    SIXTH,
-    SEVENTH;
-}

src/Calcuable.java

+public interface Calcuable
+{
+    double calculateAverage();
+    int calculateMedian();
+}

src/Course.java

+import enumeration.BachelorSemester;
+import enumeration.CourseType;
+import enumeration.ExamType;
+import enumeration.Mark;
+
 public class Course
 {
     // most attributes are concrete and can't be changed easily without changing the whole system
-    final private int id;   // PK // FK
-    final private String name;
-    final private BachelorSemester bachelorSemester;
-    final private CourseType courseType;
-    final private double sws;
-    final private int ects;
+    private final int id;   // PK // FK
+    private final String name;
+    private final BachelorSemester bachelorSemester;
+    private final CourseType courseType;
+    private final int sws;
+    private final double ects;
     private ExamType examType;
 
-    public Course(int id, String name, BachelorSemester bachelorSemester, CourseType courseType, double sws, int ects, ExamType examType)
+    public Course(int id, String name, BachelorSemester bachelorSemester, CourseType courseType, int sws, double ects, ExamType examType)
     {
         this.id = id;
         this.name = name;
@@ -19,4 +24,9 @@ public class Course
         this.ects = ects;
         this.examType = examType;
     }
+
+    public void setGrade(Mark mark)
+    {
+
+    }
 }

src/CourseType.java

-public enum CourseType
-{
-    REQUIRED,
-    ELECTIVE,
-    COMPULSORY,
-    PLV,
-}

src/CoursesOfStudy.java

+import enumeration.BachelorDegree;
+import enumeration.FieldOfStudy;
+
+import java.util.List;
+
+public class CoursesOfStudy
+{
+    private final int id;
+    private final String name;
+    private final BachelorDegree bachelorDegree;
+    private final int duration;
+    private final int fees;
+    private final List<Course> courses;
+    private FieldOfStudy fieldOfStudy;
+
+    public CoursesOfStudy(int id, String name, BachelorDegree bachelorDegree, int duration, int fees, List<Course> courses, FieldOfStudy fieldOfStudy)
+    {
+        this.id = id;
+        this.name = name;
+        this.bachelorDegree = bachelorDegree;
+        this.duration = duration;
+        this.fees = fees;
+        this.courses = courses;
+        this.fieldOfStudy = fieldOfStudy;
+    }
+}

src/Enrollment.java

+public class Enrollment
+{
+    private final int id;
+    private final int studentID;
+    private final int lecturerID;
+    private final int courseID;
+
+    public Enrollment(int id, int studentID, int lecturerID, int courseID)
+    {
+        this.id = id;
+        this.studentID = studentID;
+        this.lecturerID = lecturerID;
+        this.courseID = courseID;
+    }
+}

src/ExamType.java

-public enum ExamType
-{
-    WRITTEN,
-    ORAL,
-    RESEARCH_PROJECT,
-    TAKE_HOME;
-}

src/Gender.java

-public enum Gender
-{
-    MALE,
-    FEMALE,
-    OTHER;
-}

src/Lecturer.java

-public class Lecturer extends Person
+import enumeration.Gender;
+import enumeration.Status;
+
+import java.util.List;
+
+public class Lecturer extends UniversityMember
 {
     public Lecturer(int id, String firstName, String lastName, String placeOfResidence, String birthPlace,
-                    String officialEmail, String privateEmail, boolean isSignedUp, Gender gender, Status status)
+                    String officialEmail, String privateEmail, List<Course> personalCourses,
+                    boolean isSignedUpForCourse, Gender gender, Status status)
     {
-        super(id, firstName, lastName, placeOfResidence, birthPlace,
-                officialEmail, privateEmail, isSignedUp, gender, status);
+        super(id, gender, firstName, lastName, placeOfResidence, birthPlace,
+                officialEmail, privateEmail, personalCourses, isSignedUpForCourse);
     }
 
-    public void setGrades()
+    @Override
+    public boolean signUpForCourse(Course course)
     {
-
+        return false;
     }
 }

src/Status.java

-public enum Status
-{
-    ENROLLED,
-    ON_LEAVE,
-    EXMATRICULATED;
-}

src/Student.java

+import enumeration.BachelorSemester;
+import enumeration.Gender;
+import enumeration.Status;
+
 import java.util.List;
 
-public class Student extends Person
+public class Student extends UniversityMember implements Calcuable
 {
     // no static because variables don't make any sense without the created object
+    private Status status;
     private boolean paidFees;
-    private List<Double> grades;
-    // CourseOfStudy
     private BachelorSemester bachelorSemester;
-    private BachelorDegree bachelorDegree;
+    private List<Double> grades;
 
-    public Student(int id, String firstName, String lastName, String placeOfResidence, String birthPlace,
-                   String officialEmail, String privateEmail, boolean isSignedUp, Gender gender, Status status,
-                   boolean paidFess, List<Double> grades, BachelorSemester bachelorSemester, BachelorDegree bachelorDegree)
+    public Student(int id, Gender gender, String firstName, String lastName, String placeOfResidence, String birthPlace,
+                   String officialEmail, String privateEmail, List<Course> personalCourses, boolean isSignedUpForCourse,
+                   Status status, boolean paidFess, BachelorSemester bachelorSemester, List<Double> grades)
     {
-        super(id, firstName, lastName, placeOfResidence, birthPlace,
-                officialEmail, privateEmail, isSignedUp, gender, status);
+        super(id, gender, firstName, lastName, placeOfResidence, birthPlace,
+                officialEmail, privateEmail, personalCourses, isSignedUpForCourse);
+        this.status = status;
         this.paidFees = paidFess;
-        this.grades = grades;
         this.bachelorSemester = bachelorSemester;
-        this.bachelorDegree = bachelorDegree;
+        this.grades = grades;
     }
 
-    public List<Double> GetGrades()
+    public List<Double> getGrades()
     {
         return grades;
     }
+
+    @Override
+    public boolean signUpForCourse(Course course)
+    {
+        /*
+        personalCourses.add(course);
+
+        // return status for registration process: was successful or has failed
+        return isSignedUpForCourse = true;
+        */
+        return false;
+    }
+
+    @Override
+    public double calculateAverage()
+    {
+        return 0;
+    }
+
+    @Override
+    public int calculateMedian()
+    {
+        return 0;
+    }
 }
\ No newline at end of file

src/Person.java → src/UniversityMember.java

+import enumeration.Gender;
+
 import java.util.ArrayList;
 import java.util.List;
 
-public class Person
+public abstract class UniversityMember
 {
-    final private int id; // final for the ID because it will remain the same for the whole duration of studying or being employed
-    private Status status;
+    // final for the ID because it will remain the same for the whole duration of studying or being employed
+    // PK & FK
+    private final int id;
     private Gender gender;
     private String firstName;
     private String lastName;
     private String placeOfResidence;
-    private String birthPlace;
+    private final String birthPlace;
     private String officialEmail;
     private String privateEmail;
     private List<Course> personalCourses = new ArrayList<>();
-    private boolean isSignedUp;
+    private boolean isSignedUpForCourse;
 
-    public Person(int id, String firstName, String lastName, String placeOfResidence, String birthPlace,
-                  String officialEmail, String privateEmail, boolean isSignedUp, Gender gender, Status status)
+    public UniversityMember(int id, Gender gender, String firstName, String lastName, String placeOfResidence, String birthPlace,
+                            String officialEmail, String privateEmail, List<Course> personalCourses, boolean isSignedUpForCourse)
     {
         this.id = id;
+        this.gender = gender;
         this.firstName = firstName;
         this.lastName = lastName;
         this.placeOfResidence = placeOfResidence;
         this.birthPlace = birthPlace;
         this.officialEmail = officialEmail;
         this.privateEmail = privateEmail;
-        this.isSignedUp = isSignedUp;
-        this.gender = gender;
-        this.status = status;
+        this.personalCourses = personalCourses;
+        this.isSignedUpForCourse = isSignedUpForCourse;
     }
 
-    public boolean SignUpForCourse(Course course)
-    {
-        personalCourses.add(course);
-
-        // return status for registration process: was successful or has failed
-        return isSignedUp;
-    }
+    public abstract boolean signUpForCourse(Course course);
 }

src/enumeration/BachelorDegree.java

+package enumeration;
+
+public enum BachelorDegree
+{
+    BACHELOR_OF_SCIENCE("B. Sc."),
+    BACHELOR_OF_ENGINEERING("B. Eng.");
+
+    private String degree;
+
+    private BachelorDegree(String degree)
+    {
+        this.degree = degree;
+    }
+}

src/enumeration/BachelorSemester.java

+package enumeration;
+
+public enum BachelorSemester
+{
+    FIRST(1),
+    SECOND(2),
+    THIRD(3),
+    FOURTH(4),
+    FIFTH(5),
+    SIXTH(6),
+    SEVENTH(7);
+
+    private int semester;
+
+    private BachelorSemester(int semester)
+    {
+        this.semester = semester;
+    }
+}

src/enumeration/CourseType.java

+package enumeration;
+
+public enum CourseType
+{
+    REQUIRED("required"),
+    ELECTIVE("AWP"),
+    COMPULSORY("FWP"),
+    PLV("PLV");
+
+    private String courseType;
+
+    private CourseType(String courseType)
+    {
+        this.courseType = courseType;
+    }
+}

src/enumeration/ExamType.java

+package enumeration;
+
+public enum ExamType
+{
+    WRITTEN("written ex."),
+    RESEARCH_PROJECT("written student research project"),
+    BACHELOR_THESIS("bachelor thesis"),
+    ORAL("oral ex."),
+    ASSIGNMENT("assignment"),
+    PERFORMANCE_RECORD("TN");
+
+    private String examType;
+
+    private ExamType(String examType)
+    {
+        this.examType = examType;
+    }
+}

src/enumeration/FieldOfStudy.java

+package enumeration;
+
+public enum FieldOfStudy
+{
+    EMBEDDED_SYSTEMS,
+    MOBILE_AND_SPATIAL_SYSTEMS;
+}

src/enumeration/Gender.java

+package enumeration;
+
+public enum Gender
+{
+    MALE("Male"),
+    FEMALE("Female"),
+    OTHER("Other");
+
+    private String gender;
+
+    private Gender(String gender)
+    {
+        this.gender = gender;
+    }
+}

src/enumeration/Mark.java

+package enumeration;
+
+public enum Mark
+{
+    EINS_NULL(1.0),
+    EINS_DREI(1.3),
+    EINS_SIEBEN(1.7),
+    ZWEI_NULL(2.0),
+    ZWEI_DREI(2.3),
+    ZWEI_SIEBEN(2.7),
+    DREI_NULL(3.0),
+    DREI_DREI(3.3),
+    DREI_SIEBEN(3.7),
+    VIER_NULL(4.0),
+    FUENF_NULL(5.0);
+
+    private double mark;
+
+    Mark(double mark)
+    {
+        this.mark = mark;
+    }
+}