Android - JSON Parsing using Retrofit Library with Kotlin

JSON is a format with the help of which we can exchange the data from the server within our application or a website. For accessing this data from the server within android applications. There are several libraries that are available such as Volley and Retrofit. In this article, we will take a look at JSON Parsing in Android applications using Kotlin.  

Note: If you are looking to implement JSON Parsing in Android using Retrofit in Java language. Check out the following article: JSON Parsing in Android using Retrofit Library with Java

Step by Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.

Step 2: Add the below dependency in your build.gradle file

Below is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. We have used the Picasso dependency for image loading from the URL.  

// below dependency for using retrofit.
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.5.0'

// below dependency for using picasso image loading library
implementation 'com.squareup.picasso:picasso:2.71828'

After adding this dependency simply sync your project to install it. 

Step 3: Adding permissions to the internet in the AndroidManifest.xml file

Navigate to the app > AndroidManifest.xml and add the below code to it. 

Step 4: Working with the activity_main.xml file

Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file. 

Step 5: Creating a modal class for storing our data

Navigate to the app > java > your app’s package name > Right-click on it > New > Kotlin class and name it as RecyclerData and add the below code to it. Comments are added inside the code to understand the code in more detail.

Step 6: Creating an Interface class for our API Call

Navigate to the app > java > your app’s package name > Right-click on it > New > Kotlin class select it as Interface and name the file as RetrofitAPI and add the below code to it. Comments are added inside the code to understand the code in more detail.

Step 7: Working with the MainActivity.kt file

Go to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.

Now run your application to see the output of it. 

Output: