Programming Groovy 2

3.1 Typing in Java

We’ve all come to rely on the “safety” of compile-time type-checking. But, ​safety​ in ​type safety​ is as comforting as ​security​ in ​Social Security​.

Suppose we have a class ​Car​ with a ​year​ and an ​Engine​ class, and we want to implement the ability to clone objects of this class. We’ll ignore deeper issues with cloning in Java—see my article “Why Copying an Object Is a Terrible Thing to Do” in Appendix 1, ​Web Resources​. To clone, we implement the ​Cloneable​ interface and provide a ​public​  ​clone​ method. ​Object​’s ​clone​ can make a shallow copy of the object. However, we want different instances of ​Car​ to have different ​Engine​s. Therefore, we clone the ​Car​ using the base method but tweak it a little ...