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More Guice Please!!!: Re-Learning Google's Agile Lightweight Dependency Injection Library (Part 1.2)

In the subtitle of this tutorial, we say we are “re-learning” Google Guice because, with the growing adoption of the Scala programming language, it is necessary to re-learn libraries like Guice so that we are able to use them to build not only Java-based but also Scala-based services.  Continuing our discussion, one thing we should point out is that, when we extend the AbstractModule abstract class, we do not override the configure method of Listing 1.1 but a configure method without parameters.  In fact, if we try to override the method from Listing 1.1, you’ll get a complaint from either your compiler or IDE.  No, this is not magic.  It may be worthwhile to take a look at the AbstractModule source to see why this is the case. 

Listing 1.2: AbstractModule abstract class

public abstract class AbstractModule implements Module {

Binder binder;

public final synchronized void configure(Binder builder) {
}

protected abstract void configure();

protected Binder binder() {
..
}

...
As we see from Listing 1.2, the configure method from Listing 1.1 is final and so cannot be overridden.  The way this class is structured, we will be “building” an instance of Binder within the body of our overriding configure method.

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