A generalization of injection of dependencies to cover also other forms of injection. Thoroughly discussed in Chapter 7, Use Modular Architecture. One of the possible strategies includes use of Lookup, another Spring, there is even an option to mix them together or rely on JDK's own ServiceLoader.
It is necessary to mention that there is very fair comparison of dependency injection and service locator (like Lookup and ServiceLoader) technologies available on Martin Fowler's website since 2004. Lookup is slightly more advanced (because it is type safe in contrary to Martin's locator), but the general points made by Martin are still perfectly valid.