Use value retrieved from Firebase database outside of valueEventListener

I'm developing an app using Java and Firebase in android in that I an retrieving data from Firebase Database. Here is my code

databaseReference.orderByChild("email").equalTo(email).addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    AddFaculty addFaculty = dataSnapshot1.getValue(AddFaculty.class);
                    department = addFaculty.getDepartment();
                    year = addFaculty.getYear();
                }

            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });

Model class

public class AddFaculty {
    private String name;
    private String email;
    private String position;
    private String department;
    private String year;
    private String facultyId;

    public AddFaculty() {
    }

    public AddFaculty(String name, String email, String position, String department, String year, String facultyId) {
        this.name = name;
        this.email = email;
        this.position = position;
        this.department = department;
        this.year = year;
        this.facultyId = facultyId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPosition() {
        return position;
    }

    public void setPosition(String position) {
        this.position = position;
    }

    public String getDepartment() {
        return department;
    }

    public void setDepartment(String department) {
        this.department = department;
    }

    public String getYear() {
        return year;
    }

    public void setYear(String year) {
        this.year = year;
    }

    public String getFacultyId() {
        return facultyId;
    }

    public void setFacultyId(String facultyId) {
        this.facultyId = facultyId;
    }
}

Here is my problem. I want to use 'addFaculty' or department and year variable outside of the valueEventListener. I know many people asked question related to this. I tried many solutions related to this question but it didn't work.
So if you know how to achieve this it would be great help.

Create an interface to access the variable

interface CallbackFaculty {
    void passFaculty(AddFaculty addFaculty);
}

then you can create a function with the interface parameter

private void getFaculty(CallbackFaculty callbackFaculty) { 
     databaseReference.orderByChild("email").equalTo(email).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                AddFaculty addFaculty = dataSnapshot1.getValue(AddFaculty.class);
                department = addFaculty.getDepartment();
                year = addFaculty.getYear();
                callbackFaculty.passFaculty(addFaculty);
            }

        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });
}

to use the method

getFaculty(new CallbackFaculty {
    @Override
    public void passFaculty(AddFaculty addFaculty) {
         // here you have the access of addFaculty
         // you can try logging addFaculty to check the value
    }
});

hope it helps you