How to Update Data in API using Retrofit in Android?

We have seen reading data from API as well as posting data to our database with the help of the API. In this article, we will take a look at updating our data in our API. We will be using the Retrofit library for updating our data in our API. 

What we are going to build in this article? 

We will be building a simple application in which we will be displaying a simple form and with that form, we will be updating our data and passing it to our API to update that data. We will be using PUT request along with the Retrofit library to update our data to API. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language. 

Step by Step Implementation

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java 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. 

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

After adding this dependency sync your project and now move towards the AndroidManifest.xml part.  

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 > Java class and name it as DataModal and add the below code to it. Comments are added in the code to get to know 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 > Java class select it as RetrofitAPI and add below code to it. Comments are added in the code to get to know in more detail.

Step 7: Working with MainActivity.java file

Navigate to the app > java > your app's package name > MainActivity.java file and add the below code to it. Comments are added in the code to get to know in more detail.  

Now run your app and see the output of the app. 

Output: