Class constructor call with class as input

I'm working with a class and getting a call to this class with it as input.

 professor = new Professor(EEEE, AAAA, YEARS_90, DEP);

 depProf.addProfessor(professor)

Professor has a constructor of (String, String, Integer, String), but in a test I want to call it from another place with (Professor) as input.

public Professor(String name, String surname, Integer yearOfBirth, String department) {

    this.department = department;
    Person curPerson = new Person(name, surname, yearOfBirth);

}

How can I make a constructor of Professor(Professor)? If that make any sense.

I'm thinking about calling 1st constructor when second is called but don't actually know how to make it work.

You can call another constructor in the same class for example:

public Professor(String name, String surname, Integer yearOfBirth) {
   this.name = name;
   this.surname = surname;
   this.yearOfBirth = yearOfBirth;
}

public Professor(String name, String surname, Integer yearOfBirth, String department) {
  this(name, surname, yearOfBirth);
  this.department = department;
}

public Professor(Professor p) {
  this(p.name, p.surname, p.yearOfBirth, p.department);
}

You can use this to call another constructor.

public Professor(Professor professor) {
    this(professor.name, professor.surname, professor.yearOfBirth, professor.department);
}

If I get this right, you are trying to use a copy constructor. This constructor is generated by default in C++, but you have to manually implement one in Java, in your Professor class :

public Professor(Professor p) { 
    this(p.name, p.surname, p.yearOfBirth, p.department);
}