Dependency Injection (DI) in Android: Providing Interfaces

<p>Dependency injection is a powerful concept in Java, and Dagger2 has become one of the most popular frameworks for implementing it. One of the challenges developers often face is managing multiple implementations of a particular dependency. This article delves into how to provide interfaces in Java using Dagger2 principles to address this challenge.</p> <h1>The Problem:</h1> <p>Imagine a scenario where an application has two different types of&nbsp;<code>NetworkSetup</code>&nbsp;classes (<code>NetworkSetup</code>&nbsp;&amp;&nbsp;<code>NetworkSetupSecond</code>). The app needs to decide which version of the dependency to create and inject at different times. If we were to inject a new&nbsp;<code>NetworkSetupSecond</code>class into our other classes (<code>ComputeLayer</code>), we&#39;d have to refactor all the code, replacing all references of the first class with the second. This approach is not scalable and makes swapping classes cumbersome.</p> <h1>The Solution: Using Interfaces</h1> <p>Interfaces act as a contract or promise. When a class implements an interface, it agrees to provide specific behaviors (methods) listed in the interface. This allows different classes to be treated similarly based on the methods they&rsquo;ve agreed to implement.</p> <p>To address our problem, we can:</p> <ol> <li>Create an Interface: We&rsquo;ll define an interface named&nbsp;<code>NetworkLayer</code>&nbsp;that lists the standard methods we plan to use in both&nbsp;<code>NetworkSetup</code>&nbsp;class types.</li> </ol> <p><a href="https://medium.com/@zuhayr.codes/dependency-injection-di-in-android-providing-interfaces-day6-fdd71b631200">Website&nbsp;</a></p>