Building a voice assistant for an Android Java or Kotlin app

With Alan’s voice assistant SDK for Android, you can create a voice assistant or chatbot and embed it to your Android app written in Java or Kotlin. The Alan Platform provides you with all the tools and leverages the industry’s best Automatic Speech Recognition (ASR), Natural Language Understanding (NLU) and Speech Synthesis technologies to quickly build an in-app voice assistant from scratch.

In this tutorial, we will build a simple Android app, add a voice assistant to it and test it. The users will be able to tap the voice assistant button in the app and give custom voice commands, and Alan will reply to them.

YouTube

If you are a visual learner, watch this tutorial on Alan AI YouTube Channel.

What you will learn

  • How to add a voice assistant to an Android app written in Java or Kotlin

  • How to write custom voice commands for an Android app

What you will need

To go through this tutorial, make sure the following prerequisites are met:

  • You have signed up to Alan Studio.

  • You have created a project in Alan Studio.

  • You have set up the Android environment and it is functioning properly. For details, see Android developers documentation.

  • (If testing on an emulator) All virtual microphone settings must be enabled. To check the settings, on the emulator settings bar, click More (…) > Microphone and make sure all toggles are set to the On position.

  • (If testing on a device) The device must be connected to the Internet. The Internet connection is required to let the Android app communicate with the voice script run in the Alan Cloud.

Note

When you sign up to Alan Studio, Alan adds free interactions to your balance to let you get started. To get additional interactions to your balance, link your Alan account with your GitHub account and give stars to Alan repositories. For details, see Adding free interactions.

Step 1: Create a starter Android app

For this tutorial series, we will be using a simple Android app with a tabbed layout. Let’s create it.

  1. Open the IDE and select to start a new Android project.

  2. Select Tabbed Activity as the project template. Then click Next.

  3. Enter a project name, for example, MyApp, and select the language: Java or Kotlin.

  4. The minimum possible Android SDK version required by the Alan SDK is 21. In the Minimum SDK list, select API 21. Then click Finish.

../../../_images/tutorial-java-install.png

Step 2: Integrate the app with Alan

Now we will add the Alan button to the app.

  1. Open the build.gradle file at the module level.

  2. In the dependencies block, add the dependency configuration for the Alan Android SDK. Do not forget to sync the project.

    build.gradle
     dependencies {
       ...
       /// Adding Alan SDK dependency
       implementation 'app.alan:sdk:4.12.0'
     }
    
  3. Next, we need to add the XML layout for the Alan button to the main app activity. Open the main_activity.xml file, switch to the Code view and add the following layout to it:

    main_activity.xml
     <com.alan.alansdk.button.AlanButton
         android:id="@+id/alan_button"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_gravity="bottom"
         android:visibility="visible"
         app:button_horizontal_align="right"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"/>
    
  4. By default, the Alan button is placed in the bottom right corner of the screen. Use the button_horizontal_align property to change the button position to left for the button not to overlap with the floating button already available in the starter app.

    Here is what your main_activity.xml file should look like:

    ../../../_images/tutorial-java-xml-button.png
  5. Add the alanConfig object to the app. This object describes the parameters that are provided for the Alan button. To do this, open the MainActivity.java or MainActivity.kt file and add the following code to the MainActivity class:

    MainActivity.java
     public class MainActivity extends AppCompatActivity {
       ...
       /// Adding AlanButton variable
       private AlanButton alanButton;
    
      @Override
      protected void onCreate(Bundle savedInstanceState) {
        ...
        /// Defining the project key
        AlanConfig config = AlanConfig.builder().setProjectId("").build();
        alanButton = findViewById(R.id.alan_button);
        alanButton.initWithConfig(config);
    
        AlanCallback alanCallback = new AlanCallback() {
          /// Handling commands from Alan Studio
          @Override
          public void onCommand(final EventCommand eventCommand) {
            try {
              JSONObject command = eventCommand.getData();
              String commandName = command.getJSONObject("data").getString("command");
              Log.d("AlanButton", "onCommand: commandName: " + commandName);
            } catch (JSONException e) {
              Log.e("AlanButton", e.getMessage());
            }
          }
        };
    
        /// Registering callbacks
        alanButton.registerCallback(alanCallback);
      }
    }
    
    MainActivity.kt
     class MainActivity : AppCompatActivity() {
       ...
       /// Adding AlanButton variable
       private var alanButton: AlanButton? = null
    
       override fun onCreate(savedInstanceState: Bundle?) {
         ...
         /// Defining the project key
         val config = AlanConfig.builder().setProjectId("").build()
         alanButton = findViewById(R.id.alan_button)
         alanButton?.initWithConfig(config)
    
         val alanCallback: AlanCallback = object : AlanCallback() {
           /// Handling commands from Alan Studio
           override fun onCommand(eventCommand: EventCommand) {
             try {
               val command = eventCommand.data
               val commandName = command.getJSONObject("data").getString("command")
               Log.d("AlanButton", "onCommand: commandName: $commandName")
             } catch (e: JSONException) {
               e.message?.let { Log.e("AlanButton", it) }
             }
           }
         };
    
         /// Registering callbacks
         alanButton?.registerCallback(alanCallback);
       }
     }
    
  6. In setProjectId, we need to provide the Alan SDK key for our voice project. To get the key, in Alan Studio, at the top of the code editor click Integrations and copy the key value from the Alan SDK Key field.

    ../../../_images/alan-sdk-key.png
  7. In the MainActivity.java or MainActivity.kt file, import the necessary classes. Here is what your main activity file should look like:

    ../../../_images/tutorial-java-builder.png
  8. Run the app.

After the app is built, tap the Alan button in the app and say: Hello world.

../../../_images/alan-mobile.png

However, if you try to ask: How are you doing? Alan will not give an appropriate response. This is because the voice script in Alan Studio does not contain the necessary voice commands so far.

Step 3: Add voice commands

Let’s add some voice commands so that we can interact with Alan. In Alan Studio, open the project and in the code editor, add the following intents:

Voice script
 intent(`What is your name?`, p => {
     p.play(`It's Alan, and yours?`);
 });

 intent(`How are you doing?`, p => {
     p.play(`Good, thank you. What about you?`);
 });

Now tap the Alan button and ask: What is your name? and How are you doing? Alan will give responses we have provided in the added intents.

What’s next?

You can now go on with building a voice assistant with Alan. Here are some helpful resources: