How to Use Retrofit for Networking in Android

Making networking calls has never been easier

Photo by Ludovic Toinel on Unsplash

1. Adding the Dependencies

In your project’s build.gradle

implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.google.code.gson:gson:2.8.7'

Also, be sure to add the INTERNET permission in your manifest.xml

<uses-permission android:name="android.permission.INTERNET"/>

2. Getting Started

For our tutorial, we will be using this particular end-point. Open the link and observe its JSON Response.

If you take a look at it, you will find that its an array of POST JSON Objects.

3. Create Model

It’s always a great practice to create the model of the data we are trying to consume in our application, so let’s do that.

4. Create your Networking Repository

• Create a package called ‘networking’ in your project structure.
• Create a new Java Interface inside it and give it a name JsonPlaceHolderAPI which is the name of the API we are trying to consume.
• Depending upon the number of endpoints, create different methods. For us, we are just consuming the GET Posts endpoint. So we will create a method for it.

public interface JsonPlaceholderAPI {
@GET("posts")
    Call<List<Post>> getPosts();
}

• Notice we mention the endpoint suffix inside the @GET("posts") that way Retrofit will know what is the endpoint.
• We also mention the return type of data that we expect from this…