Create Chat Application in Android using GCM Part 2

In the previous Create Chat Application in Android using GCM we built the REST API. In this post we will build our android application. You can follow the previous Create Chat Application in Android using GCM from the link given below.

Create Chat App for Android using GCM Part 1

Our REST APIs are ready now its time to build our application. So lets begin.

Table of Contents

1 Create Chat Application in Android using GCM
2 Create Chat Application in Android Source Code and Video
3 Final Words

Create Chat Application in Android using GCM

Creating Android Studio Project

Open android studio and create a new android project. Select empty activity and next->next->finish.
Once your project is loaded, you need to add google-services.json in app directory, which you have generated while creating the app in google developer console. If you don’t know what is it just go through the Android Push Notification Tutorial using GCM.
Now inside your main package create 3 packages as shown in the image below (this step is optional you can keep all codes in the same package but for the sake of simplicity I have created these packages).

I have created activities to store all the activities, in gcm we will store gcm classes, and all the rest would go inside helper. At this time your MainActivity is inside the main package to move it inside the package activities just drag it inside activities and it will be moved there.

Adding Required Dependencies

We will be using many library dependencies for this project so this is my app level build.gradle file. You need to change your file according to this.

apply plugin: 'com.android.application'

android {

compileSdkVersion 23

buildToolsVersion "23.0.3"

defaultConfig {

applicationId "net.simplifiedcoding.simplifiedcodingchat"

minSdkVersion 15

targetSdkVersion 23

versionCode 1

versionName "1.0"

}

buildTypes {

release {

minifyEnabled false

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

}

dependencies {

compile fileTree(include: ['*.jar'], dir: 'libs')

testCompile 'junit:junit:4.12'

compile 'com.android.support:appcompat-v7:23.4.0'

//Add these

compile 'com.google.android.gms:play-services-gcm:8.3.0'

compile 'com.android.support:design:23.0.1'

compile 'com.android.support:recyclerview-v7:23.4.0'

compile 'com.android.support:cardview-v7:23.4.0'

compile 'com.android.volley:volley:1.0.0'

}

//Add this

apply plugin: 'com.google.gms.google-services'

We have added play services which is required for GCM. We have also added support design, recyclerview, CardView and volley. We will be using all these libraries.
Modify project level build.gradle file as shown below.

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

repositories {

jcenter()

}

dependencies {

classpath 'com.android.tools.build:gradle:2.1.0'

//Add these two lines

classpath 'com.google.gms:google-services:1.5.0-beta2'

classpath 'com.android.tools.build:gradle:2.0.0-alpha6'

// NOTE: Do not place your application dependencies here; they belong

// in the individual module build.gradle files

}

allprojects {

repositories {

jcenter()

}

task clean(type: Delete) {

delete rootProject.buildDir

}

Creating a class to store the constants

Create two classes inside helper package. One is Constants.java to store all the required constants and other is URLs.java to store the API URLs.
So create class named Constants.java in helper package and write the following code.

package net.simplifiedcoding.simplifiedcodingchat.helper;

/**

* Created by Belal on 5/29/2016.

public class Constants {

public static final String SHARED_PREF_NAME = "simplifiedcodingchat";

public static final String USER_ID = "userid";

public static final String USER_NAME = "username";

public static final String USER_EMAIL= "useremail";

public static final String IS_LOGGED_IN= "is_logged_in";

public static final String PUSH_NOTIFICATION = "pushnotification";

public static final int NOTIFICATION_ID = 235;

}

Now create URLs.java and write the following code.

package net.simplifiedcoding.simplifiedcodingchat.helper;

/**

* Created by Belal on 5/29/2016.

public class URLs {

public static final String ROOT_URL = "http://192.168.94.1/SimplifiedCodingChat/v1/";

public static final String URL_REGISTER = ROOT_URL + "register";

public static final String URL_STORE_TOKEN = ROOT_URL + "storegcmtoken/";

public static final String URL_FETCH_MESSAGES = ROOT_URL + "messages";

public static final String URL_SEND_MESSAGE = ROOT_URL + "send";

}

In the first constant ROOT_URL you need to change the IP according to your system. To know what your IP is you can use ipconfig command in cmd (windows user).

Creating a class to handle the network request and sharedpreferences

Now we will create a class. This class will handle the volley requests and sharedpreferences. This would be a singleton class and it will start on the app launch. So we also need to add it inside AndroidManifest.xml. So create a class named AppController.java inside helper package and write the following code.

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package net.simplifiedcoding.simplifiedcodingchat.helper;

import android.app.Application;

import android.content.Context;

import android.content.Intent;

import android.content.SharedPreferences;

import android.text.TextUtils;

import com.android.volley.Request;

import com.android.volley.RequestQueue;

import com.android.volley.toolbox.Volley;

import net.simplifiedcoding.simplifiedcodingchat.activities.MainActivity;

//Class extending application

public class AppController extends Application {

//Getting tag it will be used for displaying log and it is optional

public static final String TAG = AppController.class.getSimpleName();

//Creating a volley request queue object

private RequestQueue mRequestQueue;

//Creatting class object

private static AppController mInstance;

//Creating sharedpreferences object

//We will store the user data in sharedpreferences

private SharedPreferences sharedPreferences;

//class instance will be initialized on app launch

@Override

public void onCreate() {

super.onCreate();

mInstance = this;

}

//Public static method to get the instance of this class

public static synchronized AppController getInstance() {

return mInstance;

}

//This method would return the request queue

public RequestQueue getRequestQueue() {

if (mRequestQueue == null) {

mRequestQueue = Volley.newRequestQueue(getApplicationContext());

}

return mRequestQueue;

}

//This method would add the requeust to the queue for execution

public <T> void addToRequestQueue(Request<T> req) {

//Setting a tag to the request

req.setTag(TAG);

//calling the method to get the request queue and adding the requeust the the queuue

getRequestQueue().add(req);

}

//method to cancle the pending requests

public void cancelPendingRequests(Object tag) {

if (mRequestQueue != null) {

mRequestQueue.cancelAll(tag);

}

//Method to get sharedpreferences

public SharedPreferences getSharedPreferences() {

if (sharedPreferences == null)

sharedPreferences = getSharedPreferences(Constants.SHARED_PREF_NAME, Context.MODE_PRIVATE);

return sharedPreferences;

}

//This method will clear the sharedpreference

//It will be called on logout

public void logout() {

SharedPreferences.Editor editor = getSharedPreferences().edit();

editor.clear();

editor.apply();

}

//This method will store the user data on sharedpreferences

//It will be called on login

public void loginUser(int id, String name, String email) {

SharedPreferences.Editor editor = getSharedPreferences().edit();

editor.putInt(Constants.USER_ID, id);

editor.putString(Constants.USER_EMAIL, email);

editor.putString(Constants.USER_NAME, name);

editor.putBoolean(Constants.IS_LOGGED_IN, true);

editor.apply();

}

//This method will check whether the user is logged in or not

public boolean isLoggedIn() {

return getSharedPreferences().getBoolean(Constants.IS_LOGGED_IN, false);

}

//This method will return the user id of logged in user

public int getUserId() {

return getSharedPreferences().getInt(Constants.USER_ID, -1);

}

//This method will return the username of logged in user

public String getUserName() {

return getSharedPreferences().getString(Constants.USER_NAME, null);

}

Now add this class inside the application tag in your AndroidManifest.xml file.

<application

android:name=".helper.AppController"

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:supportsRtl="true"

android:theme="@style/AppTheme">

Creating Login Screen on MainActivity

We need a login screen to enter in the chat room. So inside activity_main.xml write the following xml code.

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".activities.MainActivity">

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentStart="true"

android:layout_centerVertical="true"

android:orientation="vertical">

<android.support.design.widget.TextInputLayout

android:id="@+id/input_layout_password"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<EditText

android:id="@+id/editTextName"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:hint="Enter Your Name"

android:inputType="text" />

</android.support.design.widget.TextInputLayout>

<android.support.design.widget.TextInputLayout

android:layout_width="match_parent"

android:layout_height="wrap_content">

<EditText

android:id="@+id/editTextEmail"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:hint="Enter Your Email"

android:inputType="textEmailAddress" />

</android.support.design.widget.TextInputLayout>

<Button

android:id="@+id/buttonEnter"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="Enter Chat Room" />

</LinearLayout>

</RelativeLayout>

The above code will generate the following UI.

create chat application in android — Login Screen

We are not using password, if the user is already registered it will be logged in or if user is not already registered it will be registered. So basicallly user need to provide his name and email to enter the Chat Room.
Now inside MainActivity.java write the following code to add the login functionality.

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package net.simplifiedcoding.simplifiedcodingchat.activities;

import android.app.Application;

import android.app.ProgressDialog;

import android.content.Intent;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import com.android.volley.AuthFailureError;

import com.android.volley.Request;

import com.android.volley.Response;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.StringRequest;

import net.simplifiedcoding.simplifiedcodingchat.R;

import net.simplifiedcoding.simplifiedcodingchat.helper.AppController;

import net.simplifiedcoding.simplifiedcodingchat.helper.URLs;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.HashMap;

import java.util.Map;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

//Views

private EditText editTextEmail;

private EditText editTextName;

private Button buttonEnter;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//Initiailizing views

editTextEmail = (EditText) findViewById(R.id.editTextEmail);

editTextName = (EditText) findViewById(R.id.editTextName);

buttonEnter = (Button) findViewById(R.id.buttonEnter);

buttonEnter.setOnClickListener(this);

//If the user is already logged in

//Starting chat room

if(AppController.getInstance().isLoggedIn()){

finish();

startActivity(new Intent(this, ChatRoomActivity.class));

}

//Method to register user

private void registerUser() {

final ProgressDialog progressDialog = new ProgressDialog(this);

progressDialog.setMessage("Entering chat room");

progressDialog.show();

final String name = editTextName.getText().toString().trim();

final String email = editTextEmail.getText().toString().trim();

StringRequest stringRequest = new StringRequest(Request.Method.POST, URLs.URL_REGISTER,

new Response.Listener<String>() {

@Override

public void onResponse(String response) {

progressDialog.hide();

try {

JSONObject obj = new JSONObject(response);

int id = obj.getInt("id");

String name = obj.getString("name");

String email = obj.getString("email");

//Login user

AppController.getInstance().loginUser(id,name,email);

//Starting chat room we need to create this activity

startActivity(new Intent(MainActivity.this, ChatRoomActivity.class));

} catch (JSONException e) {

e.printStackTrace();

}

new Response.ErrorListener() {

@Override

public void onErrorResponse(VolleyError error) {

}

}) {

@Override

protected Map<String, String> getParams() throws AuthFailureError {

Map<String, String> params = new HashMap<>();

params.put("name", name);

params.put("email", email);

return params;

}

};

AppController.getInstance().addToRequestQueue(stringRequest);

}

@Override

protected void onResume() {

super.onResume();

//Checking if user is logged in

if(AppController.getInstance().isLoggedIn()){

finish();

startActivity(new Intent(this, ChatRoomActivity.class));

}

@Override

public void onClick(View v) {

registerUser();

}

As you can see on login we are starting ChatRoomActivity so we need to create it as well.

Designing Chat Room

Create a new empty activity named ChatRoomActivity and in the respective layout file write the following xml code (in my case it is activity_chat_room.xml).

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:windowSoftInputMode="adjustPan|adjustResize"

tools:context="net.simplifiedcoding.simplifiedcodingchat.activities.ChatRoomActivity">

<android.support.v7.widget.Toolbar

android:id="@+id/toolbar"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="#2196F3"

android:minHeight="?attr/actionBarSize"></android.support.v7.widget.Toolbar>

<RelativeLayout

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_below="@+id/toolbar"

android:orientation="vertical"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin">

<android.support.v7.widget.RecyclerView

android:id="@+id/recyclerView"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_marginBottom="55dp"

android:scrollbars="vertical">

</android.support.v7.widget.RecyclerView>

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:orientation="horizontal"

android:weightSum="4">

<EditText

android:id="@+id/editTextMessage"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_weight="1"

android:hint="Enter Message"

android:lines="1" />

<Button

android:id="@+id/buttonSend"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_weight="3"

android:text="Send" />

</LinearLayout>

</RelativeLayout>

The above code would generate the following UI.

We have a RecyclerView to display the thread in the chat room. And at the bottom we have an EditText and a Button. We need to create a logout button to logout from the chat room.
Create a xml file named menu.xml inside menu folder and write the following code.

<?xml version="1.0" encoding="utf-8"?>

<item

android:id="@+id/menuLogout"

android:title="Logout" />

</menu>

We will code this activity at last.

Creating RecyclerView Layout

For RecyclerView we will create two layouts. One layout for self message which will be displayed from right and other for other’s message which will be displayed from left.
So first create chat_thread.xml inside layout folder and write the following code. This is for self message.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical">

<LinearLayout

android:background="#91d49a"

android:elevation="5dp"

android:layout_gravity="right"

android:layout_margin="3dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content">

<LinearLayout

android:padding="15dp"

android:orientation="vertical"

android:layout_width="wrap_content"

android:layout_height="wrap_content">

<TextView

android:id="@+id/textViewMessage"

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Hello how are you?" />

<TextView

android:id="@+id/textViewTime"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Belal Khan, 2016-05-29 16:02:00?"

android:textSize="12dp"

</LinearLayout>

Now create chat_thread_other.xml and write the following code. This is for other’s messages.

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical">

<LinearLayout

android:background="#d7d3f8"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_margin="3dp"

android:elevation="5dp"

android:orientation="vertical"

android:padding="15dp">

<TextView

android:id="@+id/textViewMessage"

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Hello how are you?" />

<TextView

android:id="@+id/textViewTime"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Belal Khan, 2016-05-29 16:02:00?"

android:textSize="12dp"

</LinearLayout>

</RelativeLayout>

Both above codes are same only difference is the alignment and background color. In the message part we have two textviews, the first one is large to display the message and the second one is small to display name of the sender and time of the message.
The above codes will generate the following UIs.

Creating Message

Create a class named Message inside helper package.

package net.simplifiedcoding.simplifiedcodingchat.helper;

import java.io.Serializable;

/**

* Created by Belal on 5/29/2016.

public class Message {

private int usersId;

private String message;

private String sentAt;

private String name;

public Message(int usersId, String message, String sentAt, String name) {

this.usersId = usersId;

this.message = message;

this.sentAt = sentAt;

this.name = name;

}

public int getUsersId() {

return usersId;

}

public String getMessage() {

return message;

}

public String getSentAt() {

return sentAt;

}

public String getName() {

return name;

}

I have only generated a Constructor and Getters in the above class. You can do it easily by right click->generate in the code window. This class will used to store the messages of the thread.
Now for our RecyclerView we need to create our Adapter that will show the Thread. I have also covered a recyclerview tutorial you can check to understand it better.

Creating RecyclerView Adapter

Create a class named ThreadAdapter and write the following code.

package net.simplifiedcoding.simplifiedcodingchat.helper;

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import net.simplifiedcoding.simplifiedcodingchat.R;

import java.util.ArrayList;

/**

* Created by Belal on 5/29/2016.

//Class extending RecyclerviewAdapter

public class ThreadAdapter extends RecyclerView.Adapter<ThreadAdapter.ViewHolder> {

//user id

private int userId;

private Context context;

//Tag for tracking self message

private int SELF = 786;

//ArrayList of messages object containing all the messages in the thread

private ArrayList<Message> messages;

//Constructor

public ThreadAdapter(Context context, ArrayList<Message> messages, int userId){

this.userId = userId;

this.messages = messages;

this.context = context;

}

//IN this method we are tracking the self message

@Override

public int getItemViewType(int position) {

//getting message object of current position

Message message = messages.get(position);

//If its owner id is equals to the logged in user id

if (message.getUsersId() == userId) {

//Returning self

return SELF;

}

//else returning position

return position;

}

@Override

public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

//Creating view

View itemView;

//if view type is self

if (viewType == SELF) {

//Inflating the layout self

itemView = LayoutInflater.from(parent.getContext())

.inflate(R.layout.chat_thread, parent, false);

} else {

//else inflating the layout others

itemView = LayoutInflater.from(parent.getContext())

.inflate(R.layout.chat_thread_other, parent, false);

}

//returing the view

return new ViewHolder(itemView);

}

@Override

public void onBindViewHolder(ViewHolder holder, int position) {

//Adding messages to the views

Message message = messages.get(position);

holder.textViewMessage.setText(message.getMessage());

holder.textViewTime.setText(message.getName()+", "+message.getSentAt());

}

@Override

public int getItemCount() {

return messages.size();

}

//Initializing views

public class ViewHolder extends RecyclerView.ViewHolder {

public TextView textViewMessage;

public TextView textViewTime;

public ViewHolder(View itemView) {

super(itemView);

textViewMessage = (TextView) itemView.findViewById(R.id.textViewMessage);

textViewTime = (TextView) itemView.findViewById(R.id.textViewTime);

}

Now we will create our Notification Handler.

Creating Class to Handle Push Notification

Create a class NotificationHandler and write the following code.

package net.simplifiedcoding.simplifiedcodingchat.helper;

import android.app.ActivityManager;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.graphics.BitmapFactory;

import android.os.Build;

import android.support.v4.app.NotificationCompat;

import net.simplifiedcoding.simplifiedcodingchat.R;

import net.simplifiedcoding.simplifiedcodingchat.activities.ChatRoomActivity;

import java.util.List;

/**

* Created by Ravi on 01/06/15.

public class NotificationHandler {

private Context mContext;

public NotificationHandler(Context mContext) {

this.mContext = mContext;

}

//This method would display the notification

public void showNotificationMessage(final String title, final String message) {

NotificationCompat.Builder builder = new NotificationCompat.Builder(mContext);

builder.setSmallIcon(R.mipmap.ic_launcher);

Intent intent = new Intent(mContext, ChatRoomActivity.class);

PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0, intent, 0);

builder.setContentIntent(pendingIntent);

builder.setLargeIcon(BitmapFactory.decodeResource(mContext.getResources(), R.mipmap.ic_launcher));

builder.setContentTitle(title);

builder.setContentText(message);

builder.setAutoCancel(true);

NotificationManager notificationManager = (NotificationManager) mContext.getSystemService(mContext.NOTIFICATION_SERVICE);

notificationManager.notify(Constants.NOTIFICATION_ID, builder.build());

}

//This method will check whether the app is in background or not

public static boolean isAppIsInBackground(Context context) {

boolean isInBackground = true;

ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);

if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {

List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();

for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {

if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {

for (String activeProcess : processInfo.pkgList) {

if (activeProcess.equals(context.getPackageName())) {

isInBackground = false;

}

} else {

List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);

ComponentName componentInfo = taskInfo.get(0).topActivity;

if (componentInfo.getPackageName().equals(context.getPackageName())) {

isInBackground = false;

}

return isInBackground;

}

Adding Google Cloud Messaging

For google cloud messaging we have to create three classes. We have did all these in previous GCM tutorial. So I am only pasting the codes here. First create a class named GCMRegistrationIntentService inside gcm package and write the following code.

package net.simplifiedcoding.simplifiedcodingchat.gcm;

import android.app.IntentService;

import android.content.Intent;

import android.support.v4.content.LocalBroadcastManager;

import android.util.Log;

import com.android.volley.AuthFailureError;

import com.android.volley.Request;

import com.android.volley.Response;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.StringRequest;

import com.google.android.gms.gcm.GoogleCloudMessaging;

import com.google.android.gms.iid.InstanceID;

import net.simplifiedcoding.simplifiedcodingchat.R;

import net.simplifiedcoding.simplifiedcodingchat.helper.AppController;

import net.simplifiedcoding.simplifiedcodingchat.helper.Constants;

import net.simplifiedcoding.simplifiedcodingchat.helper.URLs;

import java.util.HashMap;

import java.util.Map;

/**

* Created by Belal on 4/15/2016.

public class GCMRegistrationIntentService extends IntentService {

public static final String REGISTRATION_SUCCESS = "RegistrationSuccess";

public static final String REGISTRATION_ERROR = "RegistrationError";

public static final String REGISTRATION_TOKEN_SENT = "RegistrationTokenSent";

public GCMRegistrationIntentService() {

super("");

}

@Override

protected void onHandleIntent(Intent intent) {

registerGCM();

}

private void registerGCM() {

Intent registrationComplete = null;

String token = null;

try {

InstanceID instanceID = InstanceID.getInstance(getApplicationContext());

token = instanceID.getToken(getString(R.string.gcm_defaultSenderId), GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);

Log.w("GCMRegIntentService", "token:" + token);

sendRegistrationTokenToServer(token);

registrationComplete = new Intent(REGISTRATION_SUCCESS);

registrationComplete.putExtra("token", token);

} catch (Exception e) {

Log.w("GCMRegIntentService", "Registration error");

registrationComplete = new Intent(REGISTRATION_ERROR);

}

LocalBroadcastManager.getInstance(this).sendBroadcast(registrationComplete);

}

private void sendRegistrationTokenToServer(final String token) {

//Getting the user id from shared preferences

//We are storing gcm token for the user in our mysql database

final int id = AppController.getInstance().getUserId();

StringRequest stringRequest = new StringRequest(Request.Method.PUT, URLs.URL_STORE_TOKEN + id,

new Response.Listener<String>() {

@Override

public void onResponse(String s) {

Intent registrationComplete = new Intent(REGISTRATION_TOKEN_SENT);

LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(registrationComplete);

}

new Response.ErrorListener() {

@Override

public void onErrorResponse(VolleyError volleyError) {

}

}) {

@Override

protected Map<String, String> getParams() throws AuthFailureError {

Map<String, String> params = new HashMap<>();

params.put("token", token);

return params;

}

};

AppController.getInstance().addToRequestQueue(stringRequest);

}

Now create class GCMTokenRefreshListenerService inside gcm package and write the following codes.

package net.simplifiedcoding.simplifiedcodingchat.gcm;

import android.content.Intent;

import com.google.android.gms.iid.InstanceIDListenerService;

/**

* Created by Belal on 4/15/2016.

public class GCMTokenRefreshListenerService extends InstanceIDListenerService {

//If the token is changed registering the device again

@Override

public void onTokenRefresh() {

Intent intent = new Intent(this, GCMRegistrationIntentService.class);

startService(intent);

}

The last class we need to create in gcm package is GCMPushReceiverService. This class will actually receive the messages.

package net.simplifiedcoding.simplifiedcodingchat.gcm;

import android.app.ActivityManager;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.graphics.BitmapFactory;

import android.net.Uri;

import android.os.Build;

import android.os.Bundle;

import android.support.v4.content.LocalBroadcastManager;

import android.support.v7.app.NotificationCompat;

import android.util.Log;

import com.google.android.gms.gcm.GcmListenerService;

import net.simplifiedcoding.simplifiedcodingchat.R;

import net.simplifiedcoding.simplifiedcodingchat.helper.Constants;

import net.simplifiedcoding.simplifiedcodingchat.helper.Message;

import net.simplifiedcoding.simplifiedcodingchat.helper.NotificationHandler;

import java.util.List;

/**

* Created by Belal on 4/15/2016.

public class GCMPushReceiverService extends GcmListenerService {

@Override

public void onMessageReceived(String from, Bundle data) {

String message = data.getString("message");

String title = data.getString("title");

String id = data.getString("id");

sendNotification(message, title, id);

}

private void sendNotification(String message, String title, String id) {

//Creating a broadcast intent

Intent pushNotification = new Intent(Constants.PUSH_NOTIFICATION);

//Adding notification data to the intent

pushNotification.putExtra("message", message);

pushNotification.putExtra("name", title);

pushNotification.putExtra("id", id);

//We will create this class to handle notifications

NotificationHandler notificationHandler = new NotificationHandler(getApplicationContext());

//If the app is in foreground

if (!NotificationHandler.isAppIsInBackground(getApplicationContext())) {

//Sending a broadcast to the chatroom to add the new message

LocalBroadcastManager.getInstance(this).sendBroadcast(pushNotification);

} else {

//If app is in foreground displaying push notification

notificationHandler.showNotificationMessage(title, message);

}

Creating Chat Room

The final step is we will code the ChatRoomActivity. So come inside ChatRoomActivity.java and write the following code.

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package net.simplifiedcoding.simplifiedcodingchat.activities;

import android.app.ProgressDialog;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.Bundle;

import android.support.v4.content.LocalBroadcastManager;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.Toolbar;

import android.util.Log;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

import com.android.volley.AuthFailureError;

import com.android.volley.DefaultRetryPolicy;

import com.android.volley.Request;

import com.android.volley.Response;

import com.android.volley.RetryPolicy;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.StringRequest;

import com.google.android.gms.common.ConnectionResult;

import com.google.android.gms.common.GooglePlayServicesUtil;

import net.simplifiedcoding.simplifiedcodingchat.R;

import net.simplifiedcoding.simplifiedcodingchat.gcm.GCMRegistrationIntentService;

import net.simplifiedcoding.simplifiedcodingchat.helper.AppController;

import net.simplifiedcoding.simplifiedcodingchat.helper.Constants;

import net.simplifiedcoding.simplifiedcodingchat.helper.Message;

import net.simplifiedcoding.simplifiedcodingchat.helper.NotificationHandler;

import net.simplifiedcoding.simplifiedcodingchat.helper.ThreadAdapter;

import net.simplifiedcoding.simplifiedcodingchat.helper.URLs;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.HashMap;

import java.util.Map;

public class ChatRoomActivity extends AppCompatActivity implements View.OnClickListener {

//Broadcast receiver to receive broadcasts

private BroadcastReceiver mRegistrationBroadcastReceiver;

//Progress dialog

private ProgressDialog dialog;

//Recyclerview objects

private RecyclerView recyclerView;

private RecyclerView.LayoutManager layoutManager;

private RecyclerView.Adapter adapter;

//ArrayList of messages to store the thread messages

private ArrayList<Message> messages;

//Button to send new message on the thread

private Button buttonSend;

//EditText to send new message on the thread

private EditText editTextMessage;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_chat_room);

//Adding toolbar to activity

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);

toolbar.setTitle(AppController.getInstance().getUserName());

setSupportActionBar(toolbar);

//Displaying dialog while the chat room is being ready

dialog = new ProgressDialog(this);

dialog.setMessage("Opening chat room");

dialog.show();

//Initializing recyclerview

recyclerView = (RecyclerView) findViewById(R.id.recyclerView);

recyclerView.setHasFixedSize(true);

layoutManager = new LinearLayoutManager(this);

recyclerView.setLayoutManager(layoutManager);

//Initializing message arraylist

messages = new ArrayList<>();

//Calling function to fetch the existing messages on the thread

fetchMessages();

//initializing button and edittext

buttonSend = (Button) findViewById(R.id.buttonSend);

editTextMessage = (EditText) findViewById(R.id.editTextMessage);

//Adding listener to button

buttonSend.setOnClickListener(this);

//Creating broadcast receiver

mRegistrationBroadcastReceiver = new BroadcastReceiver() {

@Override

public void onReceive(Context context, Intent intent) {

if (intent.getAction().equals(GCMRegistrationIntentService.REGISTRATION_SUCCESS)) {

//When gcm registration is success do something here if you need

} else if (intent.getAction().equals(GCMRegistrationIntentService.REGISTRATION_TOKEN_SENT)) {

//When the registration token is sent to ther server displaying a toast

Toast.makeText(getApplicationContext(), "Chatroom Ready...", Toast.LENGTH_SHORT).show();

//When we received a notification when the app is in foreground

} else if (intent.getAction().equals(Constants.PUSH_NOTIFICATION)) {

//Getting message data

String name = intent.getStringExtra("name");

String message = intent.getStringExtra("message");

String id = intent.getStringExtra("id");

//processing the message to add it in current thread

processMessage(name, message, id);

}

};

//if the google play service is not in the device app won't work

int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());

if (ConnectionResult.SUCCESS != resultCode) {

if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {

Toast.makeText(getApplicationContext(), "Google Play Service is not install/enabled in this device!", Toast.LENGTH_LONG).show();

GooglePlayServicesUtil.showErrorNotification(resultCode, getApplicationContext());

} else {

Toast.makeText(getApplicationContext(), "This device does not support for Google Play Service!", Toast.LENGTH_LONG).show();

}

} else {

Intent itent = new Intent(this, GCMRegistrationIntentService.class);

startService(itent);

}

//This method will fetch all the messages of the thread

private void fetchMessages() {

StringRequest stringRequest = new StringRequest(Request.Method.GET, URLs.URL_FETCH_MESSAGES,

new Response.Listener<String>() {

@Override

public void onResponse(String response) {

dialog.dismiss();

try {

JSONObject res = new JSONObject(response);

JSONArray thread = res.getJSONArray("messages");

for (int i = 0; i < thread.length(); i++) {

JSONObject obj = thread.getJSONObject(i);

int userId = obj.getInt("userid");

String message = obj.getString("message");

String name = obj.getString("name");

String sentAt = obj.getString("sentat");

Message messagObject = new Message(userId, message, sentAt, name);

messages.add(messagObject);

}

adapter = new ThreadAdapter(ChatRoomActivity.this, messages, AppController.getInstance().getUserId());

recyclerView.setAdapter(adapter);

scrollToBottom();

} catch (JSONException e) {

e.printStackTrace();

}

new Response.ErrorListener() {

@Override

public void onErrorResponse(VolleyError error) {

}

});

AppController.getInstance().addToRequestQueue(stringRequest);

}

//Processing message to add on the thread

private void processMessage(String name, String message, String id) {

Message m = new Message(Integer.parseInt(id), message, getTimeStamp(), name);

messages.add(m);

scrollToBottom();

}

//This method will send the new message to the thread

private void sendMessage() {

final String message = editTextMessage.getText().toString().trim();

if (message.equalsIgnoreCase(""))

return;

int userId = AppController.getInstance().getUserId();

String name = AppController.getInstance().getUserName();

String sentAt = getTimeStamp();

Message m = new Message(userId, message, sentAt, name);

messages.add(m);

adapter.notifyDataSetChanged();

scrollToBottom();

editTextMessage.setText("");

StringRequest stringRequest = new StringRequest(Request.Method.POST, URLs.URL_SEND_MESSAGE,

new Response.Listener<String>() {

@Override

public void onResponse(String response) {

}

new Response.ErrorListener() {

@Override

public void onErrorResponse(VolleyError error) {

}

}) {

@Override

protected Map<String, String> getParams() throws AuthFailureError {

Map<String, String> params = new HashMap<>();

params.put("id", String.valueOf(AppController.getInstance().getUserId()));

params.put("message", message);

params.put("name", AppController.getInstance().getUserName());

return params;

}

};

//Disabling retry to prevent duplicate messages

int socketTimeout = 0;

RetryPolicy policy = new DefaultRetryPolicy(socketTimeout,

DefaultRetryPolicy.DEFAULT_MAX_RETRIES,

DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);

stringRequest.setRetryPolicy(policy);

AppController.getInstance().addToRequestQueue(stringRequest);

}

//method to scroll the recyclerview to bottom

private void scrollToBottom() {

adapter.notifyDataSetChanged();

if (adapter.getItemCount() > 1)

recyclerView.getLayoutManager().smoothScrollToPosition(recyclerView, null, adapter.getItemCount() - 1);

}

//This method will return current timestamp

public static String getTimeStamp() {

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

return format.format(new Date());

}

//Registering broadcast receivers

@Override

protected void onResume() {

super.onResume();

Log.w("MainActivity", "onResume");

LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,

new IntentFilter(GCMRegistrationIntentService.REGISTRATION_SUCCESS));

LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,

new IntentFilter(GCMRegistrationIntentService.REGISTRATION_ERROR));

LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,

new IntentFilter(GCMRegistrationIntentService.REGISTRATION_TOKEN_SENT));

LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,

new IntentFilter(Constants.PUSH_NOTIFICATION));

}

//Unregistering receivers

@Override

protected void onPause() {

super.onPause();

Log.w("MainActivity", "onPause");

LocalBroadcastManager.getInstance(this).unregisterReceiver(mRegistrationBroadcastReceiver);

}

//Sending message onclick

@Override

public void onClick(View v) {

if (v == buttonSend)

sendMessage();

}

//Creating option menu to add logout feature

@Override

public boolean onCreateOptionsMenu(Menu menu) {

//Adding our menu to toolbar

getMenuInflater().inflate(R.menu.menu, menu);

return true;

}

//Adding logout option here

@Override

public boolean onOptionsItemSelected(MenuItem item) {

int id = item.getItemId();

if (id == R.id.menuLogout) {

AppController.getInstance().logout();

finish();

startActivity(new Intent(this, MainActivity.class));

}

return super.onOptionsItemSelected(item);

}

The coding is done now.

Reveiwing AndroidManifest.xml

Inside AndroidManifest.xml we have to define the GCM Services and some permissions. So here is my AndroidManifest.xml. Review your manifest according to this.

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="net.simplifiedcoding.simplifiedcodingchat">

<uses-permission android:name="android.permission.INTERNET" />

<uses-permission android:name="android.permission.WAKE_LOCK" />

<permission

android:name="net.simplifiedcoding.androidgcm.permission.C2D_MESSAGE"

android:protectionLevel="signature" />

<uses-permission android:name="net.simplifiedcoding.androidgcm.permission.C2D_MESSAGE" />

<application

android:name=".helper.AppController"

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:supportsRtl="true"

android:theme="@style/AppTheme">

<activity

android:name=".activities.MainActivity"

android:label="@string/app_name"

android:theme="@style/AppTheme">

<intent-filter>

</intent-filter>

</activity>

<receiver

android:name="com.google.android.gms.gcm.GcmReceiver"

android:exported="true"

android:permission="com.google.android.c2dm.permission.SEND">

<intent-filter>

</intent-filter>

</receiver>

<service

android:name=".gcm.GCMPushReceiverService"

android:exported="false">

<intent-filter>

</intent-filter>

</service>

<service

android:name=".gcm.GCMRegistrationIntentService"

android:exported="false">

<intent-filter>

</intent-filter>

</service>

</application>

</manifest>

Thats it now run your application and you will see the following output. Just run your app twice using two different emulators.

create chat application in android using gcm — Create Chat Application in Android

Create Chat Application in Android Source Code and Video

You can check this video to see the actual output of the application.

You can download the working apk that I built for this Create Chat Application in Android Tutorial.

Download APK

You can also download my source code from GitHub. Just go to the link given below.

[sociallocker id=1372] Download Chat App Source Code [/sociallocker]

Final Words

So thats all for this Create Chat Application in Android using GCM friends. This post was very lengthy so follow it carefully if you want to make it work. If you are facing trouble try with my source code. And you can also get my working APK of this Create Chat Application in Android Tutorial.
And please do like and share this post if you find it helpful. And don’t hesitate to ask with your comments if having any confusions or doubts. Thank You 🙂

Create Chat Application in Android using GCM Part 2

Create Chat Application in Android using GCM

Creating Android Studio Project

Adding Required Dependencies

Creating a class to store the constants

Creating a class to handle the network request and sharedpreferences

Creating Login Screen on MainActivity

Designing Chat Room

Creating RecyclerView Layout

Creating Message

Creating RecyclerView Adapter

Creating Class to Handle Push Notification

Adding Google Cloud Messaging

Creating Chat Room

Reveiwing AndroidManifest.xml

Create Chat Application in Android Source Code and Video

Final Words

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