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More Guice Please!!!: Re-Learning Google's Agile Lightweight Dependency Injection Library (Part 1.4)

Let’s see if we can go through some simple examples starting with a typical XService/XServiceImpl example.  In this case, after creating the appropriate XService trait and XServiceImpl extending it, you could extend AppNameModule in the following way:

Listing 1.4: Example of Module binding XService and XServiceImpl
package com.uequations.demo.module

import com.uequations.demo.service.{XService, XServiceImpl}

object XServiceModule extends AppNameModule {

override def configure(): Unit = {
Below demonstrates code using the XService/XServiceImpl binding from (1.4):

Listing 1.5: Example of how to make use of binding

import com.uequations.demo.module.XServiceModule
import com.uequations.demo.service.XService

object DemoApp {

def main(args:Array[String]): Unit ={
  val injector = Guice.createInjector(XServiceModule)
  val instance = injector.getInstance(classOf[XService])

Here, we use the static createInjector method, but there are other ways of making use of a binding.

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Google Guice is used as a lightweight dependency injection framework that further assists developers in modularizing their applications.  Google shared this very useful library with the development community in 2010 in between the Java SE 6 and Java SE 7 releases.  This library is used in some of Java’s (and now Scala’s) most prominent libraries and platforms such as the Simian Army platform shared by Netflix.
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If you ever get a chance to look at the Module interface JavaDoc or source code, you’ll see a configure method taking a parameter of type Binder.