How to create activity recognition android app in android studio

import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.Log;
import android.widget.Toast;

import com.google.android.gms.location.ActivityRecognitionClient;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;

public class BackgroundDetectedActivitiesService extends Service {
private static final String TAG = BackgroundDetectedActivitiesService.class.getSimpleName();

private Intent mIntentService;
private PendingIntent mPendingIntent;
private ActivityRecognitionClient mActivityRecognitionClient;

IBinder mBinder = new BackgroundDetectedActivitiesService.LocalBinder();

public class LocalBinder extends Binder {
public BackgroundDetectedActivitiesService getServerInstance() {
return BackgroundDetectedActivitiesService.this;
}
}

public BackgroundDetectedActivitiesService() {

}

@Override
public void onCreate() {
super.onCreate();
mActivityRecognitionClient = new ActivityRecognitionClient(this);
mIntentService = new Intent(this, DetectedActivitiesIntentService.class);
mPendingIntent = PendingIntent.getService(this, 1, mIntentService, PendingIntent.FLAG_UPDATE_CURRENT);
requestActivityUpdatesButtonHandler();
}

@Nullable
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
return START_STICKY;
}

public void requestActivityUpdatesButtonHandler() {
Task<Void> task = mActivityRecognitionClient.requestActivityUpdates(
Constants.DETECTION_INTERVAL_IN_MILLISECONDS,
mPendingIntent);

task.addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void result) {
Toast.makeText(getApplicationContext(),
“Successfully requested activity updates”,
Toast.LENGTH_SHORT)
.show();
}
});

task.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(getApplicationContext(),
“Requesting activity updates failed to start”,
Toast.LENGTH_SHORT)
.show();
}
});
}

public void removeActivityUpdatesButtonHandler() {
Task<Void> task = mActivityRecognitionClient.removeActivityUpdates(
mPendingIntent);
task.addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void result) {
Toast.makeText(getApplicationContext(),
“Removed activity updates successfully!”,
Toast.LENGTH_SHORT)
.show();
}
});

task.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(getApplicationContext(), “Failed to remove activity updates!”,
Toast.LENGTH_SHORT).show();
}
});
}

@Override
public void onDestroy() {
super.onDestroy();
removeActivityUpdatesButtonHandler();
}
}