MainActivity.java

package com.tutsplus.activityrecognition;

import android.app.PendingIntent;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.ActivityRecognition;
import com.google.android.gms.location.ActivityRecognitionApi;
import com.google.android.gms.wallet.wobs.TimeInterval;

public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {

    public GoogleApiClient mApiClient;

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

        mApiClient = new GoogleApiClient.Builder(this)
                .addApi(ActivityRecognition.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();

        mApiClient.connect();
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        Intent intent = new Intent( this, ActivityRecognizedService.class );
        PendingIntent pendingIntent = PendingIntent.getService( this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT );
        ActivityRecognition.ActivityRecognitionApi.requestActivityUpdates( mApiClient, 3000, pendingIntent );
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }
}