Retrofit

Retrofit is a type-safe HTTP client for Android and Java. It makes it easy to send HTTP requests and process the response. It also provides support for converting JSON data to Java objects and vice versa.Here's an example of how you can use Retrofit to make an API request and process the response:

1. Set up Retrofit in your Android project. To do this, you'll need to add the necessary dependencies to your project's build.gradle file. Here's an example:

dependencies {
    implementation 'com.squareup.retrofit2:retrofit:2.9.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
}

1. Create a data model class to represent the JSON response. In this case, you'll need a class that corresponds to the structure of the JSON object. Here's an example:

public class Todo {
    private int userId;
    private int id;
    private String title;
    private boolean completed;

    // Getter and Setter methods
}

1. Create a helper class responsible for making the API request using Retrofit. Here's an example:

public class TodoApiHelper {
    private static final String BASE_URL = "https://jsonplaceholder.typicode.com/";

    private Retrofit retrofit;

    public TodoApiHelper() {
        retrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
    }

    public void getTodoItem(int todoId, Callback<Todo> callback) {
        TodoApiService todoApiService = retrofit.create(TodoApiService.class);
        Call<Todo> call = todoApiService.getTodoItem(todoId);
        call.enqueue(callback);
    }
}

1. Create an interface for the API service that defines the endpoints. Here's an example:

public interface TodoApiService {
    @GET("todos/{id}")
    Call<Todo> getTodoItem(@Path("id") int todoId);
}

1. In your UI activity or fragment, you can use the TodoApiHelper class to make the API request and update the UI. Here's an example:

public class MainActivity extends AppCompatActivity {
    private TextView titleTextView;
    private TextView completedTextView;

    private TodoApiHelper todoApiHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        titleTextView = findViewById(R.id.titleTextView);
        completedTextView = findViewById(R.id.completedTextView);

        todoApiHelper = new TodoApiHelper();
        int todoId = 1; // The ID of the todo item you want to fetch

        todoApiHelper.getTodoItem(todoId, new Callback<Todo>() {
            @Override
            public void onResponse(Call<Todo> call, Response<Todo> response) {
                if (response.isSuccessful()) {
                    Todo todo = response.body();
                    updateUI(todo);
                } else {
                    // Handle API error
                }
            }

            @Override
            public void onFailure(Call<Todo> call, Throwable t) {
                // Handle API failure
            }
        });
    }

    private void updateUI(Todo todo) {
        titleTextView.setText(todo.getTitle());
        completedTextView.setText(String.valueOf(todo.isCompleted()));
    }
}

Make sure to replace activity_main with your actual layout file containing the TextViews for displaying the title and completion status.

1. create layout file for the activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/titleTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="320dp"
        android:text="TextView"
        android:textSize="30sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/completedTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/titleTextView"
        app:layout_constraintVertical_bias="0.23" />
</androidx.constraintlayout.widget.ConstraintLayout>

Remember to add the necessary permissions and configurations for network access in your AndroidManifest.xml file.

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

This code provides a basic implementation that can be expanded upon for a more robust solution.