Logical error in if statement [Compare between two strings]

i have two string one input and another in arratlist in specific class when i compare between string in arrayList and the string [attribute]in class the two is the same but if condition not be true see this image (https://ibb.co/N6hCs5J)

i tried to debug code but i confused i can't see difference between two string

 package collegesystem;

 public class CollegeSystem {

public static void printOptions() {
    System.out.println("Welcome to our university!");
    System.out.println("Operations:");
    System.out.println("1- College");System.out.println("a) Number of Departments");System.out.println("b) Number of Courses");System.out.println("c) Number of Professors");System.out.println("d) Number of Students");System.out.println("e) Report");
    System.out.println("2- Department");System.out.println("a) New");System.out.println("b) Number of Courses");System.out.println("c) Number of Students");System.out.println("d) Is Full");System.out.println("e) Enroll");System.out.println("f) Report");
    System.out.println("3- Course");System.out.println("a) New");System.out.println("b) Number of Students");System.out.println("c) Assign");System.out.println("d) Is assigned");System.out.println("e) Professor Name");System.out.println("f) Is Full");System.out.println("g) Enroll");System.out.println("h) Report");
    System.out.println("4- Professor");System.out.println("a) New");System.out.println("b) Display Salary");System.out.println("c) Get Raise");System.out.println("d) Report");
    System.out.println("5- Student");System.out.println("a) New");System.out.println("b) Report");
    System.out.println("6- Quit");
}

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    // TODO code application logic here

    printOptions() ;
      List<Department> departmentList;departmentList = new ArrayList<>();
      List<Course> courseList ;courseList = new ArrayList<>();
      List<Professor> proffList = new ArrayList<>() ;
      List<Student> studentList;studentList = new ArrayList<>() ;



      Scanner in = new Scanner(System.in) ; 
    int d = 0 , c = 0  , p = 0 , s=0 ; 
    College AinShams = new College() ; 
    while (true){

        String option = in.nextLine() ; 
        if(!"6".equals(option)) {
            if ("2a".equals(option)) { // Define new department
                System.out.println("Department Name:");
                String depName = in.nextLine() ; 
                System.out.println("Department Description:");
                String depDescripe = in.nextLine() ;
                System.out.println("Department Max Students:");
                int max_num = in.nextInt() ;
                in.nextLine() ; 
                Department Department_Name = new Department(depName, depDescripe, max_num); 

               //  departmentList.add(Department_Name);
                 departmentList.add(d, Department_Name);
                d++ ;
                AinShams.setDepart(departmentList);

            }

            else if ("3a".equalsIgnoreCase(option)) { // new course
               System.out.println("Course Name:");
               String courseName = in.nextLine() ;
               System.out.println("Course Description:");
               String courseDescription = in.nextLine() ;
               System.out.println("Course Max Students:");
               int numOfStudent = in.nextInt() ;
               System.out.println("Course Lectures:");
               int numOfLec = in.nextInt() ;
               in.nextLine() ;
               System.out.println("Department:");
               String departmentName = in.nextLine() ;
               Course Course1 = new Course(courseName, courseDescription , departmentName, numOfStudent, numOfLec); 
               courseList.add(c,Course1);
               c++ ;
               AinShams.setCours(courseList);
             }
            else if ("5a".equalsIgnoreCase(option)) { // create new student
                System.out.println("Student Firstname:");
                String firstName = in.nextLine() ;
                System.out.println("Student Lastname:");
                String lastName = in.nextLine(); 
                System.out.println("Student telephone:");
                String telephone = in.nextLine();
                System.out.println("Student address:");
                String address = in.nextLine();
                System.out.println("Student Age:");
                int age = in.nextInt() ;
                in.nextLine();
                Student stud = new Student(firstName,lastName,telephone, address, age);
                studentList.add(s,stud) ; 
                s++ ;
                AinShams.setStudent(studentList);

        }
            else if ("2e".equalsIgnoreCase(option)) {//add student in department
                System.out.println("Department:");
                String dep= in.nextLine() ;
                System.out.println("Student:");
                String stu= in.nextLine();   
              for (int i =0 ;i< AinShams.getDepart().size() ; i++  ){
                  System.out.println("1st for loop");
                  System.out.println(dep + " " + AinShams.getDepart().get(i).getName());
               if (dep == AinShams.getDepart().get(i).getName()){
                   System.out.println("1st if condition");
                for (int j=0 ; j< AinShams.getStudent().size() ;j++){
                    System.out.println("2nd for loop");
                  if (stu == AinShams.getStudent().get(j).getFullName()){
                      System.out.println("2nd if condition");
                     AinShams.getDepart().get(i).enroll(AinShams.getStudent().get(j));
                            }
                        }
                    }

              }
             }
            System.out.println("============");
            System.out.println("Enter Operation");
            System.out.println("============");
        }



            else {break ;}


    }

}

}

i need the condition be true