调用没有硬编码参数的构造函数（耦合）

Question

I have a method which creates a new object Student and adds it to an array list studentRegister:

public void addStudent(String name, String age)
{
     studentRegister.add(new Student(name, age));
}

it calls the Student class constructor here:

public Student(String name, String age) 
{
  this.name = name;
  this.age = age;
}

This works but it is bad for maintainability as i have to change any additional parameters in both the Student class and the addStudent method. How do I input the parameters at the addStudent stage without having them harcoded in the addStudent method?

Answer 1

just do this:

public void addStudent(Student s)
{
     studentRegister.add(s);
}

And in constructer/ other methods you can call the above method as below:

public Student(String name, String age) 
{
  this.name = name;
  this.age = age;
  addStudent(this); //here is the call to the above method
}

Answer 2

You should pass a student object - Instead of the two values.

public void addStudent(Student student)
{
     studentRegister.add(student);
}

Answer 3

Using

public void addStudent(final Student student) {
    studentRegister.add(student);
}

is the better aproach.

Maybe you're looking for a simpler way to build the object. eg using chain setters:

public class Student {

    private String name;
    private String age;
    private String address;

    public String getName() {
        return name;
    }

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

    public String getAge() {
        return age;
    }

    public Student setAge(String age) {
        this.age = age;
        return this;
    }

    public String getAddress() {
        return address;
    }

    public Student setAddress(String address) {
        this.address = address;
        return this;
    }
}

So, would then:

Student student = new Student().setName("User")
                               .setAge("30")
                               .setAddress("New York");

Another way for build the object with normal setters:

Student student = new Student(){{
    setName("User");
    setAge("30");
    setAddress("30");
}};