Making a constant just final as opposed to static final leads to duplicating its value for every instance of the class, uselessly increasing the amount of memory required to execute the application.

The following code:

public class Myclass {
  public final THRESHOLD = 3;           // Non-Compliant
}

should be refactored into:

public class Myclass {
  public static final THRESHOLD = 3;    // Compliant
}