Abstraction issues

'Optional' used as field or parameter type  

Java

'instanceof' check for 'this'  

Java

'public' method not exposed in interface  

Java

'public' method with 'boolean' parameter  

Java

Chain of 'instanceof' checks  

Java

Class references one of its subclasses  

Java

Collection declared by class, not interface  

Java

Feature envy  

Java

Interface method clashes with method in 'Object'  

Java

Magic number  

Java

Overly strong type cast  

Java

Private method only used from inner class  

Java

Static member only used from one other class  

Java

Type may be weakened  

Java

Unresolved class reference  

Java

Use of concrete class  

Java