Complete CameraX Stable API Tutorial [Updated Guide]: From Setup to Advanced Use Cases

Implementing CameraX in Java: A Step-by-Step Guide

In this tutorial, we'll explore how to implement CameraX in a Java application. We'll cover everything from setting up your project to capturing photos and videos. This update is essential as we move away from the outdated alpha version of CameraX APIs to the latest stable APIs.

Watch Video Tutorial Step By Step:

Introduction

The purpose of this tutorial is to provide an updated implementation of CameraX in Java. Since many developers are still using Java, this tutorial will help you integrate CameraX with the latest stable APIs.

Setting Up the Project

Add Gradle Dependencies

First, we need to add the CameraX dependencies to our build.gradle file.

    // Add CameraX dependencies here
    def camerax_version = "1.2.2"
    implementation "androidx.camera:camera-core:${camerax_version}"
    implementation "androidx.camera:camera-lifecycle:${camerax_version}"
    implementation "androidx.camera:camera-video:${camerax_version}"
    implementation "androidx.camera:camera-view:${camerax_version}"

After adding the dependencies, sync your project with Gradle.

Update Layout

Open your activity_main.xml and update the layout by removing the existing TextView and replacing it with a PreviewView, along with buttons for capturing photos and videos. Here’s how the updated layout looks:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <PreviewView
        android:id="@+id/previewView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/capturePhotoButton"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Capture Photo"/>

        <Button
            android:id="@+id/captureVideoButton"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Capture Video"/>
    </LinearLayout>
</LinearLayout>

Implementing CameraX

Add Permissions

Ensure you add the necessary camera permissions to your AndroidManifest.xml file:

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

Initialize CameraX

In your MainActivity.java, start by getting an instance of ProcessCameraProvider:

ProcessCameraProvider cameraProviderFuture = ProcessCameraProvider.getInstance(this);
cameraProviderFuture.addListener(() -> {
    try {
        ProcessCameraProvider cameraProvider = cameraProviderFuture.get();
        startCameraX(cameraProvider);
    } catch (Exception e) {
        // Handle exceptions
    }
}, ContextCompat.getMainExecutor(this));

Start CameraX

Define the startCameraX method to set up the camera selector and preview use case:

private void startCameraX(ProcessCameraProvider cameraProvider) {
    Preview preview = new Preview.Builder().build();
    preview.setSurfaceProvider(previewView.getSurfaceProvider());

    cameraProvider.unbindAll();
    cameraProvider.bindToLifecycle(this, CameraSelector.DEFAULT_BACK_CAMERA, preview);
}

Capturing Photos

Add Image Capture Use Case

To capture photos, add an ImageCapture use case:

ImageCapture imageCapture = new ImageCapture.Builder().build();

Add a click listener to the capture photo button:

capturePhotoButton.setOnClickListener(v -> capturePhoto());

Implement the capturePhoto method:

private void capturePhoto() {
    if (imageCapture == null) return;

    ContentValues contentValues = new ContentValues();
    contentValues.put(MediaStore.Images.Media.DISPLAY_NAME, "photo_" + System.currentTimeMillis() + ".jpg");
    contentValues.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");

    ImageCapture.OutputFileOptions outputOptions = new ImageCapture.OutputFileOptions.Builder(
        getContentResolver(),
        MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
        contentValues
    ).build();

    imageCapture.takePicture(
        outputOptions,
        ContextCompat.getMainExecutor(this),
        new ImageCapture.OnImageSavedCallback() {
            @Override
            public void onImageSaved(@NonNull ImageCapture.OutputFileResults outputFileResults) {
                Toast.makeText(MainActivity.this, "Photo saved successfully", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(@NonNull ImageCaptureException exception) {
                Toast.makeText(MainActivity.this, "Failed to save photo", Toast.LENGTH_SHORT).show();
            }
        }
    );
}

Capturing Videos

Add Video Capture Use Case

Set up the VideoCapture use case:

VideoCapture videoCapture = new VideoCapture.Builder().build();

Add a click listener to the capture video button:

captureVideoButton.setOnClickListener(v -> captureVideo());

Implement the captureVideo method:

private void captureVideo() {
    if (videoCapture == null) return;

    ContentValues contentValues = new ContentValues();
    contentValues.put(MediaStore.Video.Media.DISPLAY_NAME, "video_" + System.currentTimeMillis() + ".mp4");
    contentValues.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4");

    VideoCapture.OutputFileOptions outputOptions = new VideoCapture.OutputFileOptions.Builder(
        getContentResolver(),
        MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
        contentValues
    ).build();

    videoCapture.startRecording(
        outputOptions,
        ContextCompat.getMainExecutor(this),
        new VideoCapture.OnVideoSavedCallback() {
            @Override
            public void onVideoSaved(@NonNull VideoCapture.OutputFileResults outputFileResults) {
                Toast.makeText(MainActivity.this, "Video saved successfully", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(@NonNull VideoCaptureException exception) {
                Toast.makeText(MainActivity.this, "Failed to save video", Toast.LENGTH_SHORT).show();
            }
        }
    );
}

Conclusion

With CameraX, integrating camera functionalities into your Java application has become easier and more efficient. Follow the steps outlined above to capture photos and videos using the latest APIs.