Question

Is it true that the assigned final object field may still be null inside a constructor?

class MyClass {
  private final Object obj = new Object();
  public MyClass() {
    System.out.println(obj); // may print null?
  }
}

if yes, isn’t this a bug?

Answer 1

As discussed by other answers, no, that can not happen. With an assigned final static field, however, it can.

class MyClass {
  private static MyClass myClass = new MyClass();
  private static final Object obj = new Object();
  public MyClass() {
    System.out.println(obj); // will print null once
  }
}