Complete

src/com/university/Course.java

@@ -44,7 +44,7 @@ public class Course {
     }
 
     public void enrollStudent(Student student){
-        if(student.getDepartment() == this.dpart){
+        if(student.getDepartment() == this.dpart && stds.indexOf(student) >= 0){
         stds.add(student);}
 
     }

src/com/university/Department.java

@@ -6,7 +6,7 @@ public class Department {
     private String name;
     private ArrayList<Student> stds = new ArrayList<Student>();
     private Student[] students;
-    private ArrayList<Course> crs = new ArrayList<Course>();
+    public ArrayList<Course> crs = new ArrayList<Course>();
     private Course[] courses;
     private ArrayList<Professor> prfs = new ArrayList<Professor>();
     private Professor[] professors;
@@ -19,8 +19,9 @@ public class Department {
     }
 
     public void addStudent(Student student){
-        if(student.getDepartment().getName() == this.name){
+        if(student.getDepartment().getName() == this.name && stds.indexOf(student) <= -1 ){
             stds.add(student);
+
         }
 
     }
@@ -32,15 +33,13 @@ public class Department {
 
     public void removeStudent(Student student){
         if(student.getDepartment().getName() == this.name){
-            for(Student std : students){
-                if(std == student)
-                stds.remove(student);}
+                stds.remove(student);
         }
 
     }
 
     public void addCourse(Course course){
-        if(course.getDepartment().getName() == this.name) {
+        if(course.getDepartment().getName() == this.name && crs.indexOf(course) <= -1) {
             crs.add(course);
         }
 
@@ -57,7 +56,7 @@ public class Department {
     }
 
     public void addProfessor(Professor professor){
-        if(professor.getDepartment().getName() == this.name){
+        if(professor.getDepartment().getName() == this.name && prfs.indexOf(professor) <= -1){
             prfs.add(professor);
         }
 

src/com/university/Professor.java

@@ -5,7 +5,8 @@ import java.util.ArrayList;
 public class Professor {
     private String name;
     private Department dpart;
-    private ArrayList<Course> crs = new ArrayList<Course>();
+    private ArrayList<Course> cors = new ArrayList<Course>();
+    private Course[] courses;
 
     public Professor(Department department, String name) {
         this.name = name;
@@ -21,6 +22,13 @@ public class Professor {
     }
 
     public Course[] getCourses() {
-        return null;
+        for(Course cr : dpart.crs){
+            if(cr.getProfessor().getName() == this.name){
+                cors.add(cr);
+            }
+        }
+
+        courses = cors.toArray(new Course[cors.size()]);
+        return courses;
     }
 }

src/com/university/StudnetTest.java

-package com.university;
-
-import org.junit.Test;
-import org.junit.jupiter.api.BeforeAll;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-
-
-public class StudnetTest {
-    static Student student;
-    static Department department;
-
-    @BeforeAll
-    public static void createStudent(){
-        department = new Department("Computer and IT Eng");
-        student = new Student("Alireza", "1234", "Software Eng", department);
-    }
-
-    @Test
-    public void testStudentGetName(){
-
-        assertEquals("Alireza", student.getName());
-    }
-
-    @Test
-    public void testStudenGetCourses(){
-        assertNotNull(student.getCourses());
-        assertEquals(0, student.getCourses().length);
-    }
-
-}

src/com/university/University.java

 package com.university;
 
+import java.util.ArrayList;
+
 public class University {
+    private String name;
+    private ArrayList<Department> dprmts = new ArrayList<Department>();
+    private Department[] departments;
+
+    public University(String name){
+        this.name = name;
+    }
+    public String getName(){
+        return name;
+    }
     public Department[] getDepartments(){
-        return null;
+        departments = dprmts.toArray(new Department[dprmts.size()]);
+        return departments;
     }
 
-    public void addDepartment(Department department){ }
+    public void addDepartment(Department department){
+        if(dprmts.indexOf(department)<= -1)
+            dprmts.add(department);
+    }
 
-    public void removeDepartment(Department department){ }
+    public void removeDepartment(Department department){
+        if(dprmts.indexOf(department) >= 0){
+            dprmts.remove(department);
+        }
+    }
 }

src/com/university/test.java

-package com.university;
-
-public class test {
-    public static void main(String[] args){
-        Department dp = new Department("amirkabir");
-        Student st = new Student("Mohammad" , "1234" , "Mechanic" , dp);
-        System.out.println(st.getName());
-    }
-
-}

src/test/CourseTest.java

@@ -66,8 +66,6 @@ public class CourseTest {
     }
     @Test
     public void testCourseEnrollStudents(){
-        for(Student std : stds){
 
     }
-    }
 }

src/test/DepartmentTest.java

@@ -12,12 +12,62 @@ import static junit.framework.TestCase.assertNotNull;
 import static org.junit.Assert.assertNotEquals;
 
 public class DepartmentTest {
-    static Department department;
+    static Department department , department2;
 
     @BeforeAll
     public static void CreateDepartment(){
         department = new Department("Computer");
         Student student = new Student("Ali" , "3212" , "Computer" , department);
+        Professor professor1 = new Professor(department , "salmani");
+        department.addStudent(student);
+        department2 = new Department("mechanic");
+        Professor professor2 = new Professor(department2 , "Ohadi");
+        Student student1 = new Student("Mohammad" , "9321078" , "Mechanic" , department2);
+        department2.addStudent(student);
+        Student student2 = new Student("Ali" , "1234" , "Computer" , department);
+        department.addStudent(student2);
+        department.removeStudent(student);
+        Student student3 = new Student("reza" , "2132" , "Computer" , department);
+        department.addStudent(student3);
+        Course course1 = new Course("12" , "ap" , department  , professor1 , 21 );
+        department.addCourse(course1);
+        Course course2 = new Course("12" , "ap" , department2  , professor2 , 21 );
+        department.removeCourse(course2);
+        department.addProfessor(professor1);
+        department2.addProfessor(professor1);
+    }
+
+    @Test
+    public void TestAddStudent(){
+        assertEquals(0 , department2.getStudents().length); //can't add student
+        assertNotNull(department.getStudents().length);
+    }
+
+    @Test
+    public void TestremoveStudents(){
+        assertEquals(2 , department.getStudents().length);
+    }
+
+    @Test
+    public void TestGetName0(){
+        assertEquals("Computer" , department.getName());
+    }
 
+    @Test
+    public void TestAddCourse(){
+        assertNotNull(department.getCourses().length);
+        assertEquals(0 , department2.getCourses().length);
     }
+
+    @Test
+    public void TestAddProfessor(){
+        assertNotNull(department.getProfessors().length);
+        assertEquals(0 , department2.getProfessors().length);
+    }
+
+
+
+
+
+
 }

src/test/TestProfessor.java

+package test;
+import com.university.*;
+
+import static junit.framework.TestCase.assertNotNull;
+import static junit.framework.TestCase.assertEquals;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class TestProfessor {
+    static Professor professor;
+
+    @BeforeAll
+    public static void CreateProfessor(){
+        Department department = new Department("Computer");
+        professor = new Professor(department , "Salmani");
+        Course course = new Course("1234" , "AP" , department , professor , 21);
+        department.addCourse(course);
+        department.addProfessor(professor);
+    }
+
+    @Test
+    public void TestGetName(){
+        assertEquals("Salmani" , professor.getName());
+    }
+
+    @Test
+    public void TestGetDepartment(){
+        assertEquals("Computer" , professor.getDepartment().getName());
+    }
+
+    @Test
+    public void TestgetCourses(){
+        assertNotNull(professor.getCourses());
+    }
+}

src/test/UniversityTest.java

+package test;
+
+import com.university.*;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+import static org.junit.Assert.assertNotEquals;
+
+public class UniversityTest {
+    static University university;
+
+    @BeforeAll
+    public static void CreateUniversity(){
+        university = new University("AmirKabir");
+        Department department = new Department("Omran");
+        Department department1 = new Department("Computer");
+        Department department2 = new Department("AeroSpace");
+        university.addDepartment(department);
+        university.addDepartment(department1);
+        university.addDepartment(department2);
+        university.removeDepartment(department);
+    }
+
+    @Test
+    public void TestaddDepartments(){
+        assertNotNull(university.getDepartments().length);
+    }
+
+    @Test
+    public void TestremoveDepartments(){
+        assertEquals(2 , university.getDepartments().length);
+    }
+
+    @Test
+    public void TestgetName(){
+        assertEquals("AmirKabir" , university.getName());
+    }
+}