I got the same StackOverflowError while calling hashCode of my entity class. I used guava Objects’ hashCode implementation. The hashCode method itself is generated by eclipse guava plugin and the method call includes a class member which is recursively reference the class itself again. In this case hashCode implementation go through this cyclic dependency and calls again and again itself. So I learned, i must be careful using auto generated hashCode or toString methods, especially by entity objects which reference another object with reference back to this entity.