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  • Shayne Riley thinks this is interesting:

nstead of extending an existing class, give your new class a private field that references an instance of the existing class. This design is called composition because the existing class becomes a component of the new one. Each instance method in the new class invokes the corresponding method on the contained instance of the existing class and returns the results. This is known as forwarding, and the methods in the new class are known as forwarding methods. The resulting class will be rock solid, with no dependencies on the implementation details of the existing class. Even adding new methods to the existing class will ...


Cover of Effective Java, 2nd Edition


But man is it more tedious, too