Un constructor, donde los datos pueden estar vacíos.

public class Person {
  private String name;
  private int age;

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

  public Person () {}

  public String getName() {
    return name;
  }

  public int getAge() {
    return age;
  }

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

  public void setAge(int age) {
    this.age= age;
  }
}