What's the best way to fix this 'write to static field from instance method' findbugs warning?

Question

I have a class that looks similar to this, and findbugz is complaining about the 'write to the static field from the instance method' (initialize(), and killStaticfield()). I can't set the static field in the ctor.

• What is the best fix for this issue?

• Would putting staticField in an AtomicReference suffice?

   public class Something
   {
    private static SomeClass staticField = null;
    private AnotherClass aClass;
    public Something()
    {
  
    }
  
    public void initialize()
    {
      //must be ctor'd in initialize
      aClass = new AnotherClass();
      staticField = new SomeClass( aClass );
    }
  
    public void killStaticField()
    {
     staticField = null;
    }
  
    public static void getStaticField()
    {
      return staticField;
    }
  }
  

Answer 1

Staying as close as possible to your original design...

public class Something {
  private static volatile SomeClass staticField = null;

  public Something() {
  }

  public static SomeClass getStaticField() {
    if(Something.staticField == null)
      Something.staticField = new SomeClass();;
    return Something.staticField;
  }
}

Refer to your static variable via the class name, that will remove the findbugz warning. Mark your static variable as volatile, which will make the reference safer in a multithreaded environment.

Even better would be:

public class Something {
  private static final SomeClass staticField = new SomeClass();

  public Something() {
  }

  public static SomeClass getStaticField() {
    return Something.staticField;
  }
}