آموزش ساخت برنامه چت با Firebase Cloud Messaging

import com.google.firebase.messaging.FirebaseMessagingService;
 
public class FirebaseService extends FirebaseMessagingService {
 
}

<service
    android:name=".FirebaseService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        <action android:name="com.google.firebase.MESSAGING_EVENT"/>
    </intent-filter>
</service>

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;
 
public class FirebaseService extends FirebaseMessagingService {
 
    @Override
    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
    }
}

private String sender;     رشته نام فرستنده پیام
private String content;  رشته متن پیام    
private boolean isMe;برای فهمیدن اینکه پیام دریافتی است یا ارسالی      
private Date date;             تاریخ پیام         
 
import java.util.Date;
public class Message {
    private String sender;
    private String content;
    private boolean isMe;
    private Date date;
     
    public Message(String sender, String content, boolean isMe, Date date) {
        this.sender = sender;
        this.content = content;
        this.isMe = isMe;
        this.date = date;
    }
 
    public String getSender() {
        return sender;
    }
 
    public void setSender(String sender) {
        this.sender = sender;
    }
 
    public String getContent() {
        return content;
    }
 
    public void setContent(String content) {
        this.content = content;
    }
 
    public boolean getIsMe() {
        return isMe;
    }
 
    public void setIsMe(boolean isMe) {
        this.isMe = isMe;
    }
 
    public Date getDate() {
        return date;
    }
 
    public void setDate(Date date) {
        this.date = date;
    }
}

import android.app.Activity;
import android.content.Context;
 
public class Application extends android.app.Application {
    public static Context context;
    public static Activity activity;
}

public interface onReceived {
    void onReceivedMessage(Message message);
}

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;
 
public class FirebaseService extends FirebaseMessagingService {
 
 
    onReceived onReceived;
 
    public void setOnReceived(onReceived onReceived) {
        this.onReceived = onReceived;
    }
 
    @Override
    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);            
    }
}

import android.content.SharedPreferences;
import androidx.annotation.NonNull;
import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;
import java.util.Date;
import java.util.Map;
 
public class FirebaseService extends FirebaseMessagingService {
 
 
    onReceived onReceived;
 
    public void setOnReceived(com.example.chat.onReceived onReceived) {
        this.onReceived = onReceived;
    }
 
    @Override
    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        Map<String, String> map = remoteMessage.getData();
        long time = remoteMessage.getSentTime();
        String sender = (String) map.values().toArray()[0];
        String content = (String) map.values().toArray()[1];
        SharedPreferences sh = Application.activity.getPreferences(MODE_PRIVATE);
        String name = sh.getString("name", null);
        boolean isme = name != null && name.equals(sender);
        Message message = new Message(sender, content, isme, new Date(time));
        if(onReceived != null){
            onReceived.onReceivedMessage(message);
        }
 
    }
}

<?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"
    android:background="@color/back_blue"
    tools:context=".MainActivity">
 
    <EditText
        android:id="@+id/edt_name"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_marginStart="12dp"
        android:layout_marginTop="200dp"
        android:layout_marginEnd="12dp"
        android:hint="Name"
        android:textColorHint="@color/light_gray"
        android:textColor="@color/light_gray"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.666"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
    <EditText
        android:id="@+id/edt_topic"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_margin="12dp"
        android:hint="Topic"
        android:textColorHint="@color/light_gray"
        android:textColor="@color/light_gray"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.666"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/edt_name" />
 
    <Button
        android:id="@+id/btn_subscribe"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_margin="12dp"
        android:text="Subscribe"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.666"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/edt_topic" />
 
</androidx.constraintlayout.widget.ConstraintLayout>

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import com.google.firebase.messaging.FirebaseMessaging;
public class MainActivity extends AppCompatActivity {
    EditText edtName, edtTopic;
    Button btnSubscribe;
    SharedPreferences sh;
    SharedPreferences.Editor editor;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        edtName = findViewById(R.id.edt_name);
        edtTopic = findViewById(R.id.edt_topic);
        btnSubscribe = findViewById(R.id.btn_subscribe);
        sh = getPreferences(MODE_PRIVATE);
        editor = sh.edit();
        String name = sh.getString("name", "");
        if (!name.equals("")) {
            edtName.setText(name); 
        btnSubscribe.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (edtTopic.getText().toString().isEmpty() &&      !edtName.getText().toString().isEmpty()) {
                    Bundle bundle = new Bundle();
                    editor.putString("name", edtName.getText().toString());
                    editor.apply();
   try {FirebaseMessaging.getInstance().subscribeToTopic(edtTopic.getText().toString());
                        Intent intent = new Intent(getApplication(), ChatActivity.class);
                        intent.putExtra("topic", edtTopic.getText().toString());
                        intent.putExtra("name", edtName.getText().toString());
                        startActivity(intent);
                    } catch (Exception e) {
                        Toast.makeText(getApplicationContext(), "Can not subscribe", Toast.LENGTH_SHORT).show();
                    }} else {
                    Toast.makeText(getApplicationContext(), "Please fill all fields", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}
 
 
 
}

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <rotate
            android:fromDegrees="-45"
            android:pivotX="0%"
            android:pivotY="0%"
            android:toDegrees="0" >
            <shape android:shape="rectangle" >
                <solid android:color="@color/income_blue" />
            </shape>
        </rotate>
    </item>
    <item android:left="16dp">
        <shape android:shape="rectangle" >
            <solid android:color="@color/income_blue" />
            <corners android:radius="14dp" />
        </shape>
    </item>
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <rotate
            android:fromDegrees="45"
            android:pivotX="100%"
            android:pivotY="0%"
            android:toDegrees="0">
            <shape android:shape="rectangle">
                <solid android:color="@color/out_blue" />
            </shape>
        </rotate>
    </item>
    <item android:right="16dp">
        <shape android:shape="rectangle">
            <solid android:color="@color/out_blue" />
            <corners android:radius="14dp" />
        </shape>
    </item>
</layer-list>

<?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"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="8dp"
    android:layout_marginEnd="8dp"
    android:background="@color/back_blue"
    android:padding="8dp">
     
    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/main_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/income_bubble_shape"
        android:paddingLeft="24dp"
        android:paddingTop="2dp"
        android:paddingRight="5dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">
 
        <TextView
            android:id="@+id/txt_sender"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/out_blue"
            android:textSize="16sp"
            android:textStyle="bold"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
 
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/txt_sender">
 
            <TextView
                android:id="@+id/txt_content"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="6dp"
                android:maxWidth="230dp"
                android:minWidth="70dp"
                android:paddingLeft="6dp"
                android:paddingTop="4dp"
                android:paddingRight="6dp"
                android:textColor="@color/light_gray"
                android:textSize="16sp" />
        </LinearLayout>
 
    </androidx.constraintlayout.widget.ConstraintLayout>
 
 
 
    <TextView
        android:id="@+id/txt_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="4dp"
        android:textColor="@color/light_gray"
        android:textSize="10sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@id/main_layout" />
     
</androidx.constraintlayout.widget.ConstraintLayout>

<?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"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/back_blue"
    android:padding="2dp"
    android:layout_marginEnd="8dp"
    android:layout_marginTop="8dp">
 
 
    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/main_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingRight="15dp"
        android:background="@drawable/outgoing_bubble_shape"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent">
 
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent">
 
            <TextView
                android:id="@+id/txt_content_me"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="8dp"
                android:maxWidth="230dp"
                android:paddingLeft="12dp"
                android:paddingTop="8dp"
                android:paddingRight="12dp"
                android:minWidth="50dp"
                android:textColor="@color/light_gray"
                android:textSize="16sp" />
        </LinearLayout>
 
    </androidx.constraintlayout.widget.ConstraintLayout>
 
    <TextView
        android:id="@+id/txt_time_me"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/light_gray"
        android:textSize="10sp"
        android:layout_marginEnd="4dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/main_layout" />
 
 
</androidx.constraintlayout.widget.ConstraintLayout>

<?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"
    android:background="@color/back_blue"
    tools:context=".ChatActivity">
 
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:background="@color/back_blue"
        app:layout_constraintBottom_toTopOf="@+id/edt_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
    <EditText
        android:id="@+id/edt_content"
        android:layout_width="0dp"
        android:layout_height="55dp"
        android:hint="Message"
        android:layout_marginStart="12dp"
        android:textColor="@color/light_gray"
        android:textColorHint="@color/light_gray"
        android:background="@color/back_blue"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/btn_send"
        app:layout_constraintStart_toStartOf="parent" />
 
    <ImageButton
        android:id="@+id/btn_send"
        android:layout_width="55dp"
        android:layout_height="55dp"
        android:src="@drawable/ic_baseline_send_24"
        android:background="@color/back_blue"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />
 
</androidx.constraintlayout.widget.ConstraintLayout>

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
 
public class MessageAdapter extends RecyclerView.Adapter {
 
    private ArrayList<Message> messages;
    private static final int VIEW_TYPE_MESSAGE_SENT = 0;
    private static final int VIEW_TYPE_MESSAGE_RECEIVE = 1;
 
    @Override
    public int getItemViewType(int position) {
        Message message = messages.get(position);
        if (message.getIsMe())
            return VIEW_TYPE_MESSAGE_SENT;
        return VIEW_TYPE_MESSAGE_RECEIVE;
    }
 
    public MessageAdapter(ArrayList<Message> messages) {
        this.messages = messages;
    }
 
    public void addMessage(Message messages) {
        this.messages.add(messages);
        notifyDataSetChanged();
    }
 
 
    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view;
        if (viewType == VIEW_TYPE_MESSAGE_SENT) {
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.sent_message, parent, false);
            return new SentVH(view);
        } else if (viewType == VIEW_TYPE_MESSAGE_RECEIVE) {
            view = LayoutInflater.from(parent.getContext()).inflate(R.layout.received_message, parent, false);
            return new ReceiveVH(view);
        }
        return null;
    }
 
    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        Message message = messages.get(position);
        switch (holder.getItemViewType()) {
            case VIEW_TYPE_MESSAGE_SENT:
                ((SentVH) holder).bind(message);
                break;
            case VIEW_TYPE_MESSAGE_RECEIVE:
                ((ReceiveVH) holder).bind(message);
        }
    }
    @Override
    public int getItemCount() {
        return messages.size();
    }
}
 
class SentVH extends RecyclerView.ViewHolder {
    TextView txtContent, txtTime;
 
    public SentVH(View itemView) {
        super(itemView);
        txtContent = itemView.findViewById(R.id.txt_content_me);
        txtTime = itemView.findViewById(R.id.txt_time_me);
    }
 
    public void bind(Message message) {
        txtContent.setText(message.getContent());
        txtTime.setText(message.getDate().getHours() + ":" + message.getDate().getMinutes());
    }
}
 
 
class ReceiveVH extends RecyclerView.ViewHolder {
    TextView txtSender, txtContent, txtTime;
 
    public ReceiveVH(View itemView) {
        super(itemView);
        txtSender = itemView.findViewById(R.id.txt_sender);
        txtContent = itemView.findViewById(R.id.txt_content);
        txtTime = itemView.findViewById(R.id.txt_time);
    }
 
    public void bind(Message message) {
        txtSender.setText(message.getSender());
        txtContent.setText(message.getContent());
        txtTime.setText(message.getDate().getHours() + ":" + message.getDate().getMinutes());
    }
}

private class sendMessage extends AsyncTask<String, Void, Integer> {
    @Override
    protected Integer doInBackground(String... strings) {
final String KEY = "YOUR_API_KEY"; // change this to your api key
        String endpoint = "https://fcm.googleapis.com/fcm/send";
        String title = strings[0];
        String content = strings[1];
        String topic = strings[2];
        try {
            URL url = new URL(endpoint);
            HttpsURLConnection httpsURLConnection = (HttpsURLConnection) url.openConnection();
            httpsURLConnection.setReadTimeout(10000);
            httpsURLConnection.setConnectTimeout(15000);
            httpsURLConnection.setRequestMethod("POST");
            httpsURLConnection.setDoInput(true);
            httpsURLConnection.setDoOutput(true);
            httpsURLConnection.setRequestProperty("authorization", "key=" + KEY);
            httpsURLConnection.setRequestProperty("Content-Type", "application/json");
            JSONObject body = new JSONObject();
            JSONObject data = new JSONObject();
            data.put("title", title);
            data.put("content", content);
            body.put("data", data);
            body.put("to", "/topics/" + topic);
            OutputStream outputStream = new BufferedOutputStream(httpsURLConnection.getOutputStream());
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "utf-8"));
            writer.write(body.toString());
            writer.flush();
            writer.close();
            outputStream.close();
            int responseCode = httpsURLConnection.getResponseCode();
            String responseMessage = httpsURLConnection.getResponseMessage();
            Log.d("asdasd", responseCode + " : " + responseMessage);
            InputStream inputStream = null;
            if (responseCode >= 400 && responseCode <= 499) {
                inputStream = httpsURLConnection.getErrorStream();
                issues.onError();
            } else {
                inputStream = httpsURLConnection.getInputStream();
            }
            String result = inputStream.toString();
            Log.e("asdasd", result);
            if (responseCode == 200) {
                Log.e("asdasd", "Success sent message");
                issues.onSuccess();
            } else {
                Log.e("asdasd", "Error Response");
                issues.onError();
            }
        } catch (Exception ex) {
            Log.e("asdasd", ex.toString());
            issues.onError();
        }
        return null;
    }
}

public class ChatActivity extends AppCompatActivity {
 
    String name, topic;
    EditText edtContent;
    ImageButton btnSend;
    MessageAdapter adapter;
    RecyclerView recyclerView;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chat);
        edtContent = findViewById(R.id.edt_content);
        btnSend = findViewById(R.id.btn_send);
        recyclerView = findViewById(R.id.recycler);
        Bundle bundle = getIntent().getExtras();
        name = bundle.getString("name");
        topic = bundle.getString("topic");
        adapter = new MessageAdapter(new ArrayList<>());
        recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext(), RecyclerView.VERTICAL, false));
        recyclerView.setAdapter(adapter);
        btnSend.setOnClickListener(v -> {
            sendMessage message = new sendMessage();
            message.execute(name, edtContent.getText().toString(), topic);
            edtContent.setText("");
        });
        FirebaseService.setOnReceived(new onReceived() {
            @Override
            public void onReceivedMessage(Message message) {
                runOnUiThread(new Runnable() {
    @Override
    public void run() {
        adapter.addMessage(message);
    }
});
 
            }
        });
 
    }
}