How to Use Firebase ML Kit Smart Replies in Android?

Last Updated : 21 Mar, 2025

We have seen using chatbots in Android for replying to the most common questions from the users. In this article, we will take a look at the implementation of Firebase ML Kit smart replies in Android. Firebase ML Kit smart replies are used to provide smart replies to the questions asked by the users using the Firebase ML Kit.

What we are going to build in this article?

We will be building a simple application in which we will be making a chatting-like interface in which the user will post his query in the chat box and according to the user’s query we will get to see the message from Firebase ML Kit.

Step by Step Implementation

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio.

Step 2: Connect your app to Firebase and add

Navigate to Tools on the top bar. After that click on Firebase. A new window will open on the right side. Inside that window click on Firebase ML and then click on Use Firebase ML kit in Android. You can see the option below screenshot.

After clicking on this option on the next screen click on Connect to Firebase option to connect your app to Firebase. After the setup is completed, click on Add Firebase ML to you app and add all the dependencies.

Step 3: Adding dependency for language translation and add View Binding support

Navigate to the Gradle Scripts > build.gradle.kts(Module:app) and add the below dependency in the dependencies section.

dependencies {
    ...
    implementation ("com.google.firebase:firebase-ml-natural-language-smart-reply-model:20.0.8")
}

And in the same add the following code anywhere under android tag

buildFeatures {
    viewBinding = true
}

Now sync your project and let’s move towards the implementation of Firebase ML Kit smart replies.

Step 4: Working with the MainActivity and it’s layout file

Navigate to the MainActivity and activity_main.xml and make the following changes.

MainActivity.java

package org.geeksforgeeks.demo;  import android.os.Bundle; import android.view.View; import android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; import androidx.recyclerview.widget.LinearLayoutManager; import com.google.firebase.ml.naturallanguage.FirebaseNaturalLanguage; import com.google.firebase.ml.naturallanguage.smartreply.FirebaseTextMessage; import com.google.firebase.ml.naturallanguage.smartreply.SmartReply; import com.google.firebase.ml.naturallanguage.smartreply.SmartReplySuggestionResult; import org.geeksforgeeks.demo.databinding.ActivityMainBinding; import java.util.ArrayList; import java.util.List;  public class MainActivity extends AppCompatActivity {      private List<FirebaseTextMessage> messageList;     private ArrayList<MessageModel> messageModelArrayList;     private Adapter adapter;      private ActivityMainBinding binding;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         binding = ActivityMainBinding.inflate(getLayoutInflater());         setContentView(binding.getRoot());          messageList = new ArrayList<>();         messageModelArrayList = new ArrayList<>();         adapter = new Adapter(this, messageModelArrayList);          LinearLayoutManager manager = new LinearLayoutManager(this);         binding.recyclerView.setLayoutManager(manager);         binding.recyclerView.setAdapter(adapter);          binding.sendButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 String message = binding.messageEditText.getText().toString();                 if (message.isEmpty()) {                     Toast.makeText(MainActivity.this, "Please enter your message..", Toast.LENGTH_SHORT).show();                     return;                 }                 sendMessage(message);                 binding.messageEditText.setText("");             }         });     }      private void sendMessage(String userMessage) {                  // Create a FirebaseTextMessage         FirebaseTextMessage message = FirebaseTextMessage.createForRemoteUser(                 userMessage, System.currentTimeMillis(), "uid");          messageList.add(message);                  // 0 -> user message         messageModelArrayList.add(new MessageModel(userMessage, 0));                   adapter.notifyDataSetChanged();          // Firebase Smart Reply         SmartReply smartReply = FirebaseNaturalLanguage.getInstance().getSmartReply();          smartReply.suggestReplies(messageList)                 .addOnSuccessListener(smartReplySuggestionResult -> {                     if (smartReplySuggestionResult.getStatus() == SmartReplySuggestionResult.STATUS_NOT_SUPPORTED_LANGUAGE) {                         Toast.makeText(MainActivity.this, "Language not supported..", Toast.LENGTH_SHORT).show();                     } else if (smartReplySuggestionResult.getStatus() == SmartReplySuggestionResult.STATUS_SUCCESS) {                         if (!smartReplySuggestionResult.getSuggestions().isEmpty()) {                             messageModelArrayList.add(new MessageModel(smartReplySuggestionResult.getSuggestions().get(0).getText(), 1));                             adapter.notifyDataSetChanged();                         }                     }                 })                 .addOnFailureListener(e ->                      Toast.makeText(MainActivity.this, "Fail to get data: " + e.getMessage(), Toast.LENGTH_SHORT).show());     } }

MainActivity.kt

package org.geeksforgeeks.demo  import android.os.Bundle import android.view.View import android.widget.Toast import androidx.appcompat.app.AppCompatActivity import androidx.recyclerview.widget.LinearLayoutManager import com.google.firebase.ml.naturallanguage.FirebaseNaturalLanguage import com.google.firebase.ml.naturallanguage.smartreply.FirebaseTextMessage import com.google.firebase.ml.naturallanguage.smartreply.SmartReplySuggestionResult import org.geeksforgeeks.demo.databinding.ActivityMainBinding  class MainActivity : AppCompatActivity() {     private var messageList: MutableList<FirebaseTextMessage>? = null     private var messageModelArrayList: ArrayList<MessageModel>? = null     private var adapter: Adapter? = null      private val binding: ActivityMainBinding by lazy {         ActivityMainBinding.inflate(layoutInflater)     }      override fun onCreate(savedInstanceState: Bundle?) {         super.onCreate(savedInstanceState)         setContentView(binding.root)          messageList = ArrayList()         messageModelArrayList = ArrayList()         adapter = Adapter(this, messageModelArrayList!!)         val manager = LinearLayoutManager(this)         binding.recyclerView.setLayoutManager(manager)         binding.recyclerView.setAdapter(adapter)          binding.sendButton.setOnClickListener(View.OnClickListener {             val message = binding.messageEditText.text.toString()             if (message.isEmpty()) {                 Toast.makeText(this, "Please enter your message..", Toast.LENGTH_SHORT)                     .show()                 return@OnClickListener             }              sendMessage(message)             binding.messageEditText.setText("")         })     }      private fun sendMessage(userMessage: String) {                  // pass user input to firebase as message         val message = FirebaseTextMessage.createForRemoteUser(             binding.messageEditText.text.toString(),             System.currentTimeMillis(),             "uid"         )         messageList!!.add(message)          // 0-> user message         // 1-> Firebase message         messageModelArrayList!!.add(MessageModel(userMessage, 0))          adapter!!.notifyDataSetChanged()          // Firebase smart reply instance         val smartReply = FirebaseNaturalLanguage.getInstance().smartReply          // suggest reply for user message         smartReply.suggestReplies(messageList!!)             .addOnSuccessListener { smartReplySuggestionResult ->                                  // checking if the language is not supported                 if (smartReplySuggestionResult.status == SmartReplySuggestionResult.STATUS_NOT_SUPPORTED_LANGUAGE) {                     Toast.makeText(this, "Language not supported..", Toast.LENGTH_SHORT).show()                 } else if (smartReplySuggestionResult.status == SmartReplySuggestionResult.STATUS_SUCCESS) {                     messageModelArrayList!!.add(                         MessageModel(smartReplySuggestionResult.suggestions[0].text, 1)                     )                     adapter!!.notifyDataSetChanged()                 }             }             .addOnFailureListener { e -> // inside on failure method we are displaying a toast message                 Toast.makeText(this, "Fail to get data.." + e.message, Toast.LENGTH_SHORT).show()             }     } }

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">      <!--recycler view for displaying our chat messages-->     <androidx.recyclerview.widget.RecyclerView         android:id="@+id/recyclerView"         android:layout_width="match_parent"         android:layout_height="0dp"         tools:listitem="@layout/msg_rv_item"         app:layout_constraintBottom_toTopOf="@+id/messageLayout"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toTopOf="parent" />      <LinearLayout         android:id="@+id/messageLayout"         android:layout_width="match_parent"         android:layout_height="80dp"         android:orientation="horizontal"         android:gravity="center"         android:weightSum="5"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent">          <!--edit text for entering user message-->         <EditText             android:id="@+id/messageEditText"             android:layout_width="0dp"             android:layout_height="wrap_content"             style="@style/Widget.Material3.TextInputEditText.OutlinedBox"             android:hint="Write your message here..."             android:layout_weight="4"             android:importantForAutofill="no"             android:inputType="textShortMessage" />          <!--fab for sending message-->         <com.google.android.material.floatingactionbutton.FloatingActionButton             android:id="@+id/sendButton"             android:layout_width="0dp"             android:layout_height="wrap_content"             android:layout_weight="1"             android:importantForAccessibility="no"             android:src="@android:drawable/sym_action_chat"             app:tint="@color/white"             app:backgroundTint="@color/colorPrimary" />     </LinearLayout>  </androidx.constraintlayout.widget.ConstraintLayout>

Step 5: Creating a modal class for storing our data

As we are displaying all our data in our RecyclerView. So we have to store this data in a modal class. For creating a modal class, Navigate to the app > java > your app’s package name > Right-click on it > New > Java/Kotlin class and name it as ChatMsgModal and add the below code to it. Comments are added inside the code to understand the code in more detail.

MessageModel.java

package org.geeksforgeeks.demo;  public class MessageModel {     private String message;     private int type;      public MessageModel(String message, int type) {         this.message = message;         this.type = type;     }      public String getMessage() {         return message;     }      public void setMessage(String message) {         this.message = message;     }      public int getType() {         return type;     }      public void setType(int type) {         this.type = type;     } }

MessageModel.kt

package org.geeksforgeeks.demo class MessageModel( var message: String, var type: Int )

Step 6: Creating a layout file and Adapter for each item of the message

Navigate to the app > res > layout, Right-click on it, New > layout resource file and name it as msg_rv_item. Then, navigate to the app > kotlin+java > {package-name}, Right-click on it, New > Java/Kotlin class and name it as Adapter.

Adapter.java

package org.geeksforgeeks.demo;  import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import androidx.annotation.NonNull; import androidx.cardview.widget.CardView; import androidx.core.content.ContextCompat; import androidx.recyclerview.widget.RecyclerView; import java.util.ArrayList;  public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {     private final Context context;     private final ArrayList<MessageModel> messageModelArrayList;      public Adapter(Context context, ArrayList<MessageModel> messageModelArrayList) {         this.context = context;         this.messageModelArrayList = messageModelArrayList;     }      public static class ViewHolder extends RecyclerView.ViewHolder {         TextView msgTV;         CardView msgCV;          public ViewHolder(@NonNull View itemView) {             super(itemView);             msgTV = itemView.findViewById(R.id.idTVMessage);             msgCV = itemView.findViewById(R.id.idCVMessage);         }     }      @NonNull     @Override     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {         View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_rv_item, parent, false);         return new ViewHolder(view);     }      @Override     public void onBindViewHolder(@NonNull ViewHolder holder, int position) {         MessageModel modal = messageModelArrayList.get(position);          holder.msgTV.setText(modal.getMessage());          if (modal.getType() == 1) {             holder.msgCV.setCardBackgroundColor(ContextCompat.getColor(context, R.color.colorPrimaryDark));             holder.msgTV.setTextColor(ContextCompat.getColor(context, R.color.white));         }     }      @Override     public int getItemCount() {         return messageModelArrayList.size();     } }

Adapter.kt

package org.geeksforgeeks.demo  import android.content.Context import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import android.widget.TextView import androidx.cardview.widget.CardView import androidx.recyclerview.widget.RecyclerView  class Adapter (     private val context: Context,     private val messageModelArrayList: ArrayList<MessageModel> ) : RecyclerView.Adapter<Adapter.ViewHolder>() {      inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {         val msgTV: TextView = itemView.findViewById(R.id.idTVMessage)         val msgCV: CardView = itemView.findViewById(R.id.idCVMessage)     }      override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {         val view = LayoutInflater.from(parent.context).inflate(R.layout.msg_rv_item, parent, false)         return ViewHolder(view)     }      override fun getItemCount(): Int = messageModelArrayList.size      override fun onBindViewHolder(holder: ViewHolder, position: Int) {         val modal = messageModelArrayList[position]         if (modal.type == 0) {             holder.msgTV.text = modal.message         } else {             holder.msgTV.text = modal.message             holder.msgCV.setCardBackgroundColor(context.resources.getColor(R.color.colorPrimaryDark))             holder.msgTV.setTextColor(context.resources.getColor(R.color.white))         }     } }

msg_rv_item.xml

<?xml version="1.0" encoding="utf-8"?> <androidx.cardview.widget.CardView     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:id="@+id/idCVMessage"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_margin="5dp"     app:cardCornerRadius="8dp"     app:cardElevation="5dp">      <!--text view for displaying our message-->     <TextView         android:id="@+id/idTVMessage"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_margin="4dp"         android:padding="5dp"         android:text="Message"         android:textColor="@color/black" />  </androidx.cardview.widget.CardView>

Output:

Note: You will get a certain delay in reply from Firebase for the first time. Also, the response from Firebase will not be accurate as this response are send from the Firebase ML kit model.

How to Use Firebase Cloud Messaging (FCM) in Android?

chaitanyamunje

Improve

Article Tags :