Send Push Notification to Our App Using FCM in PHP

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Hello Friends, today we’ll see how to send push notification to our app using FCM in PHP. Firebase Cloud Messaging (FCM) is a cross-platform messaging solution that lets you reliably send messages at no cost. Notification can be sent from Firebase Console also see screenshot below but if we want to send notification directly from our web server to achieve some automation or just to add some feature then this code will help.

To send push notification we need Server Key and device registration ids if we want to send notification to specific devices. But we can send to a topic also where all the devices will receive notification registered to that topic. Server Key we can get from Firebase Console -> Project Settings -> Cloud Messaging after creating project in Firebase Console and device registration id from the app itself (see logcat screenshot below) that will be sent to our server, which we can store to database for further use. But in this example I am not saving it to database just for the simplicity but you can use according to your need. We also need an app to test our push notification, so I’ll share android app code as well in this post.

Let’s start coding but before starting code, here is the Lifecycle Flow of Firebase Cloud Messaging (FCM)

Register devices to receive messages from FCM.
Send and receive downstream messages.

PushNotification.php

<?php

class PushNotification {

    private static $API_ACCESS_KEY = "AAAAocCl4Mg:APA91bFYF93LgK7wWEIweyR5fIQHuRtPGaAyLuFs5zr7Yq4w19ifxQc43lC9EnMgVfxO0WqfVXTpxeSt9HjFh5wroA8u1oozZa6EyakjXQzyVZZmXVyoH9nXBoKyDNrscLUvXGLQYT4_"; // YOUR FIREBASE API_KEY

    public static function sendNotification($target = array(), $fields = array(), $data = array()) {

        $postdata = array();
        /*
         * setting registrations ids or to only one at a time
         * because we can send notfication to registrations ids or to at once 
         */
        if (isset($target['registration_ids']) && is_array($target['registration_ids']) && !empty($target['registration_ids'])) {
            $postdata['registration_ids'] = $target['registration_ids'];
        } else if (isset($target['topic']) && trim($target['topic']) <> "") {
            $postdata['to'] = "/topics/" . $target['topic'];
        }
        /* setting Notification title & message body */
        $postdata['notification'] = array('title' => $fields['title'], 'body' => $fields['body']);
        /* setting custom data if not empty */
        if (!empty($data)) {
            $postdata['data'] = $data;
        }

        $headers = array(
            'Authorization: key=' . self::$API_ACCESS_KEY,
            'Content-Type: application/json'
        );

        #Send Request To FireBase Server
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, "https://fcm.googleapis.com/fcm/send"); //API URL of FCM
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($postdata));
        $result = curl_exec($ch);
        curl_close($ch);
        return $result;
    }

    public static function registerForNotification($token, $topic = "android") {
        //$url = "https://iid.googleapis.com/iid/v1:batchRemove";
        $fields['registration_tokens'] = is_array($token) ? $token : array($token);
        $fields['to'] = '/topics/' . $topic;

        $headers = array(
            'Authorization: key=' . self::$API_ACCESS_KEY,
            'Content-Type:application/json'
        );

        #Send Request To FireBase Server
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, 'https://iid.googleapis.com/iid/v1:batchAdd');
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
        $result = curl_exec($ch);
        curl_close($ch);
        return $result;
    }

}

<?php

class PushNotification {

private static $API_ACCESS_KEY = "AAAAocCl4Mg:APA91bFYF93LgK7wWEIweyR5fIQHuRtPGaAyLuFs5zr7Yq4w19ifxQc43lC9EnMgVfxO0WqfVXTpxeSt9HjFh5wroA8u1oozZa6EyakjXQzyVZZmXVyoH9nXBoKyDNrscLUvXGLQYT4_"; // YOUR FIREBASE API_KEY

public static function sendNotification($target = array(), $fields = array(), $data = array()) {

$postdata = array();

* setting registrations ids or to only one at a time

* because we can send notfication to registrations ids or to at once

if (isset($target['registration_ids']) && is_array($target['registration_ids']) && !empty($target['registration_ids'])) {

$postdata['registration_ids'] = $target['registration_ids'];

} else if (isset($target['topic']) && trim($target['topic']) <> "") {

$postdata['to'] = "/topics/" . $target['topic'];

}

/* setting Notification title & message body */

$postdata['notification'] = array('title' => $fields['title'], 'body' => $fields['body']);

/* setting custom data if not empty */

if (!empty($data)) {

$postdata['data'] = $data;

}

$headers = array(

'Authorization: key=' . self::$API_ACCESS_KEY,

'Content-Type: application/json'

);

#Send Request To FireBase Server

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, "https://fcm.googleapis.com/fcm/send"); //API URL of FCM

curl_setopt($ch, CURLOPT_POST, true);

curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($postdata));

$result = curl_exec($ch);

curl_close($ch);

return $result;

}

public static function registerForNotification($token, $topic = "android") {

//$url = "https://iid.googleapis.com/iid/v1:batchRemove";

$fields['registration_tokens'] = is_array($token) ? $token : array($token);

$fields['to'] = '/topics/' . $topic;

$headers = array(

'Authorization: key=' . self::$API_ACCESS_KEY,

'Content-Type:application/json'

);

#Send Request To FireBase Server

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://iid.googleapis.com/iid/v1:batchAdd');

curl_setopt($ch, CURLOPT_POST, true);

curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));

$result = curl_exec($ch);

curl_close($ch);

return $result;

}

There are two functions I have created in the PushNotification class here one sendNotification and another one registerForNotification. Just as name suggests sendNotification used to send notification while registerForNotification registers device id to a topic. This PushNotfication.php will be included in both register.php and index.php to use this class and its functions.

register.php

<?php

include './PushNotification.php';

$action = isset($_REQUEST['action']) ? trim($_REQUEST['action']) : "";

if ($action == 'register-device-token') {
    if (!isset($_REQUEST['key']) || trim($_REQUEST['key']) !== 'TESTKEY') {
        echo "security key not provided or invalid";
        exit;
    }
    if (!isset($_REQUEST['token'])) {
        echo "device token needed!!!";
        exit;
    }
    /* this token can also be stored in database for further logic/use */
    $token = trim($_REQUEST['token']);
    $topic = isset($_REQUEST['topic']) ? trim($_REQUEST['topic']) : 'android';

    echo PushNotification::registerForNotification($token, $topic);
    exit;
}

<?php

include './PushNotification.php';

$action = isset($_REQUEST['action']) ? trim($_REQUEST['action']) : "";

if ($action == 'register-device-token') {

if (!isset($_REQUEST['key']) || trim($_REQUEST['key']) !== 'TESTKEY') {

echo "security key not provided or invalid";

exit;

}

if (!isset($_REQUEST['token'])) {

echo "device token needed!!!";

exit;

}

/* this token can also be stored in database for further logic/use */

$token = trim($_REQUEST['token']);

$topic = isset($_REQUEST['topic']) ? trim($_REQUEST['topic']) : 'android';

echo PushNotification::registerForNotification($token, $topic);

exit;

}

index.php (send notification ui)

<?php
include './PushNotification.php';

if (isset($_POST['send'])) {
    $registration_ids = array();
    foreach ($_POST['registration_ids'] as $regid) {
        if (trim($regid) <> "") {
            $registration_ids[] = $regid;
        }
    }
    if (!empty($registration_ids)) {
        $target['registration_ids'] = $registration_ids;
    } else {
        $target['topic'] = trim($_POST['topic']);
    }
    $fields = array(
        'title' => isset($_POST['title']) ? trim($_POST['title']) : "",
        'body' => isset($_POST['body']) ? trim($_POST['body']) : ""
    );
    $data = array();
    foreach ($_POST['key'] as $key => $value) {
        if (trim($value) <> "") {
            $data[$value] = $_POST['value'][$key];
        }
    }
    $response = PushNotification::sendNotification($target, $fields, $data);
}
?>
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Push Notification</title>
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.5.0/css/font-awesome.min.css">
    </head>
    <body>
        <h1>Send Notification</h1>
        <form method="post">
            <table>
                <tr>
                    <td style="vertical-align: top;">
                        <label>Topic</label><br/>
                        <select name="topic">
                            <option value="">-Select-</option>
                            <option value="android">Android</option>
                        </select>
                    </td>
                    <td>Or</td>
                    <td>
                        <label>Registration Ids</label>
                        <table>
                            <tbody id="registrationIds_container">
                                <tr id="regid0">
                                    <td><input type="text" name="registration_ids[]" placeholder="Registration Id"/></td>
                                </tr>
                            </tbody>
                            <tfoot>
                                <tr>
                                    <td style="text-align: right"><a href="javascript:;" onclick="addRegId()">Add</a></td>
                                </tr>
                            </tfoot>
                        </table>
                    </td>
                </tr>
            </table>
            <br/><br/>

            <label>Title</label><br/>
            <input type="text" name="title"/>
            <br/><br/>
            <label>Message</label><br/>
            <textarea name="body" style="width: 490px; height: 100px;"></textarea>
            <br/><br/>
            <label>Custom Data</label><br/>
            <table>
                <tbody id="custom_data_container">
                    <tr id="data0">
                        <td><input type="text" name="key[]" placeholder="Key"/></td>
                        <td><input type="text" name="value[]" placeholder="Value"/></td>
                    </tr>
                </tbody>
                <tfoot>
                    <tr>
                        <td></td>
                        <td style="text-align: right"><a href="javascript:;" onclick="addCustomData()">Add</a></td>
                    </tr>
                </tfoot>
            </table>
            <p><?= isset($response) ? $response : "" ?></p>
            <input type="submit" name="send" value="Send"/>
        </form>

        <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.0/jquery.min.js" integrity="sha256-xNzN2a4ltkB44Mc/Jz3pT4iU1cmeR0FkXs4pru/JxaQ=" crossorigin="anonymous"></script>
        <script>
            function addRegId() {
                var count = $("#registrationIds_container tr").length + 1;

                var item = '<tr id="regid' + count + '">';
                item += '<td><input type="text" name="registration_ids[]" placeholder="Registration Id"/></td>';
                item += '<td><a href="javascript:void();" onclick="deleteRow(\'regid' + count + '\')" class="btn btn-sm btn-danger" title="Delete"><i class="fa fa-trash"></i></a></td>';
                item += '</tr>';

                $('#registrationIds_container').append(item);
            }
            function addCustomData() {
                var count = $("#custom_data_container tr").length + 1;

                var item = '<tr id="data' + count + '">';
                item += '<td><input type="text" name="key[]" placeholder="Key"/></td>';
                item += '<td><input type="text" name="value[]" placeholder="Value"/></td>';
                item += '<td><a href="javascript:void();" onclick="deleteRow(\'data' + count + '\')" class="btn btn-sm btn-danger" title="Delete"><i class="fa fa-trash"></i></a></td>';
                item += '</tr>';

                $('#custom_data_container').append(item);
            }

            function deleteRow(id) {
                $("#" + id).remove();
            }
        </script>
    </body>
</html>

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<?php

include './PushNotification.php';

if (isset($_POST['send'])) {

$registration_ids = array();

foreach ($_POST['registration_ids'] as $regid) {

if (trim($regid) <> "") {

$registration_ids[] = $regid;

}

if (!empty($registration_ids)) {

$target['registration_ids'] = $registration_ids;

} else {

$target['topic'] = trim($_POST['topic']);

}

$fields = array(

'title' => isset($_POST['title']) ? trim($_POST['title']) : "",

'body' => isset($_POST['body']) ? trim($_POST['body']) : ""

);

$data = array();

foreach ($_POST['key'] as $key => $value) {

if (trim($value) <> "") {

$data[$value] = $_POST['value'][$key];

}

$response = PushNotification::sendNotification($target, $fields, $data);

}

<!DOCTYPE html>

<html>

<head>

<title>Push Notification</title>

</head>

<body>

<h1>Send Notification</h1>

<table>

<tr>

<label>Topic</label><br/>

<option value="">-Select-</option>

<option value="android">Android</option>

</select>

</td>

<td>

<label>Registration Ids</label>

<table>

</tr>

</tbody>

<tfoot>

<tr>

</tr>

</tfoot>

</table>

</td>

</tr>

</table>

<label>Title</label><br/>

<label>Message</label><br/>

<label>Custom Data</label><br/>

<table>

</tr>

</tbody>

<tfoot>

<tr>

</tr>

</tfoot>

</table>

</form>

function addRegId() {

var count = $("#registrationIds_container tr").length + 1;

var item = '<tr id="regid' + count + '">';

item += '<td><input type="text" name="registration_ids[]" placeholder="Registration Id"/></td>';

item += '<td><a href="javascript:void();" onclick="deleteRow(\'regid' + count + '\')" class="btn btn-sm btn-danger" title="Delete"><i class="fa fa-trash"></i></a></td>';

item += '</tr>';

$('#registrationIds_container').append(item);

}

function addCustomData() {

var count = $("#custom_data_container tr").length + 1;

var item = '<tr id="data' + count + '">';

item += '<td><input type="text" name="key[]" placeholder="Key"/></td>';

item += '<td><input type="text" name="value[]" placeholder="Value"/></td>';

item += '<td><a href="javascript:void();" onclick="deleteRow(\'data' + count + '\')" class="btn btn-sm btn-danger" title="Delete"><i class="fa fa-trash"></i></a></td>';

item += '</tr>';

$('#custom_data_container').append(item);

}

function deleteRow(id) {

$("#" + id).remove();

}

</script>

</body>

</html>

Android App Code

Our server side code is ready to send notification now but we need an app to test whether our code is working or not. Let’s move to the app part, firstly we need a firebase configuration file to allow our app to interact with firebase. And to get configuration file we have to setup project and app on firebase console. But here I’ll not explain how to setup project, app and download configuration file as it is better explained on official website. Hence, we’ll see only coding and adding dependency part here and to setup project, app and downloading and pasting configuration file in our android project below link can help.

https://firebase.google.com/docs/android/setup#console

Now here is the android app code

MainActivity.java

package com.zatackcoder.pushnotificationexample;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

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

        TextView textView = findViewById(R.id.text);
        /**
         * Notification Data Received in Intent Extras if App not Running or in Background
         **/
        Bundle bundle = getIntent().getExtras();
        if (bundle != null) {
            String dataText = "";
            for (String key : bundle.keySet()) {
                dataText += key + " = " + bundle.get(key) + "\n";
            }
            dataText = "Data Received from Notification\n\n" + dataText.trim();
            textView.setText(dataText);
        }
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);

        TextView textView = findViewById(R.id.text);
        /**
         * Notification Data Received in Intent Extras when App is Running
         **/
        Bundle bundle = intent.getExtras();
        if (bundle != null) {
            String dataText = "";
            for (String key : bundle.keySet()) {
                dataText += key + " = " + bundle.get(key) + "\n";
            }
            dataText = "Data Received from Notification\n\n" + dataText.trim();
            textView.setText(dataText);
        }

    }
}

package com.zatackcoder.pushnotificationexample;

import android.content.Intent;

import android.os.Bundle;

import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

TextView textView = findViewById(R.id.text);

/**

* Notification Data Received in Intent Extras if App not Running or in Background

**/

Bundle bundle = getIntent().getExtras();

if (bundle != null) {

String dataText = "";

for (String key : bundle.keySet()) {

dataText += key + " = " + bundle.get(key) + "\n";

}

dataText = "Data Received from Notification\n\n" + dataText.trim();

textView.setText(dataText);

}

@Override

protected void onNewIntent(Intent intent) {

super.onNewIntent(intent);

TextView textView = findViewById(R.id.text);

/**

* Notification Data Received in Intent Extras when App is Running

**/

Bundle bundle = intent.getExtras();

if (bundle != null) {

String dataText = "";

for (String key : bundle.keySet()) {

dataText += key + " = " + bundle.get(key) + "\n";

}

dataText = "Data Received from Notification\n\n" + dataText.trim();

textView.setText(dataText);

}

Here in the MainActivity class, I have overridden onNewIntent method because this will be called from PendingIntent of notification when we click on notification and our app is running but when our app is not running then custom data will be received in extras of the intent of our launcher activity which we are extracting in onCreate method here. For more info kindly check below link

https://firebase.google.com/docs/cloud-messaging/android/receive

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">

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Firebase Notification Example"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:gravity="center"/>

</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"

tools:context=".MainActivity">

<TextView

android:id="@+id/text"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Firebase Notification Example"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent"

android:gravity="center"/>

</androidx.constraintlayout.widget.ConstraintLayout>

JsonParser.java

package com.zatackcoder.pushnotificationexample;


import android.util.Log;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;

/**
 * Created by rajesh kumar sahanee on 19/9/17.
 */

public class JsonParser {

    private final String TAG = "Json Parser";
    private HttpURLConnection conn;
    private final StringBuilder result = new StringBuilder();
    private JSONObject jsonObject;

    public JSONObject post(String url, HashMap<String, String> params, HashMap<String, String> files) {

        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setDoInput(true);//Allow Inputs
            conn.setDoOutput(true);//Allow Outputs
            conn.setUseCaches(false);//Don't use a cached Copy
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Accept-Charset", "UTF-8");
            conn.setReadTimeout(10000);
            conn.setConnectTimeout(50000);
            String boundary = "*****";
            if (files != null) {
                conn.setRequestProperty("ENCTYPE", "multipart/form-data");
                conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
                for (String key : files.keySet()) {
                    conn.setRequestProperty(key, files.get(key));
                }
            }

            conn.connect();
            DataOutputStream dataOutputStream = new DataOutputStream(conn.getOutputStream());

            //file uploading
            String twoHyphens = "--";
            String lineEnd = "\r\n";
            if (files != null) {
                for (String key : files.keySet()) {
                    int bytesRead, bytesAvailable, bufferSize;
                    byte[] buffer;
                    int maxBufferSize = 1024 * 1024; //1 * 1024 * 1024

                    File selectedFile = new File(files.get(key));
                    if (!selectedFile.isFile()) {
                        break;
                    }

                    dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);
                    //writing bytes to data outputstream
                    dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"" + key + "\";filename=\"" + files.get(key) + "\"" + lineEnd);

                    dataOutputStream.writeBytes(lineEnd);

                    FileInputStream fileInputStream = new FileInputStream(selectedFile);
                    //returns no. of bytes present in fileInputStream
                    bytesAvailable = fileInputStream.available();
                    //selecting the buffer size as minimum of available bytes or 1 MB
                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
                    //setting the buffer as byte array of size of bufferSize
                    buffer = new byte[bufferSize];

                    //reads bytes from FileInputStream(from 0th index of buffer to buffersize)
                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);

                    //loop repeats till bytesRead = -1, i.e., no bytes are left to read
                    while (bytesRead > 0) {
                        //write the bytes read from inputstream
                        dataOutputStream.write(buffer, 0, bufferSize);
                        bytesAvailable = fileInputStream.available();
                        bufferSize = Math.min(bytesAvailable, maxBufferSize);
                        bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                    }

                    dataOutputStream.writeBytes(lineEnd);
                    dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);
                    fileInputStream.close();
                }
            }
            //parameters writing when file uploading
            if (params != null && files != null) {
                for (String key : params.keySet()) {
                    dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);
                    dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"" + key + "\"" + lineEnd);
                    dataOutputStream.writeBytes(lineEnd);
                    dataOutputStream.writeBytes(params.get(key));
                    dataOutputStream.writeBytes(lineEnd);
                    dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);
                }
            }
            //parameters writing when no file uploading
            else if (params != null) {
                StringBuilder psb = new StringBuilder();
                boolean flag = false;
                for (String key : params.keySet()) {
                    try {
                        if (flag) {
                            psb.append("&");
                        }
                        psb.append(key).append("=").append(URLEncoder.encode(params.get(key), "UTF-8"));

                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                    flag = true;
                }
                dataOutputStream.writeBytes(psb.toString());
            }

            Log.d(TAG, "RC: " + conn.getResponseCode() + " RM: " + conn.getResponseMessage());

            dataOutputStream.flush();
            dataOutputStream.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            //Receive the response from the server
            BufferedReader reader = new BufferedReader(new InputStreamReader(new BufferedInputStream(conn.getInputStream())));

            String line;
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }

            Log.d(TAG, "Result: " + result.toString());

        } catch (IOException e) {
            e.printStackTrace();
        }

        conn.disconnect();

        // try parse the string to a JSON object
        try {
            jsonObject = new JSONObject(result.toString());
        } catch (JSONException e) {
            Log.e(TAG, "Error parsing data " + e.toString());
        }

        // return JSON Object
        return jsonObject;
    }

    public JSONObject get(String url, HashMap<String, String> params) {

        StringBuilder psb = new StringBuilder();
        boolean flag = false;
        for (String key : params.keySet()) {
            if (flag) {
                psb.append("&");
            }
            try {
                psb.append(key).append("=").append(URLEncoder.encode(params.get(key), "UTF-8"));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            flag = true;
        }

        if (psb.length() != 0) {
            url += "?" + psb.toString();
            Log.d(TAG, "url: " + url);
        }

        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setDoOutput(false);
            conn.setRequestMethod("GET");
            conn.setRequestProperty("Accept-Charset", "UTF-8");
            conn.setConnectTimeout(15000);
            conn.connect();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            //Receive the response from the server
            BufferedReader reader = new BufferedReader(new InputStreamReader(new BufferedInputStream(conn.getInputStream())));

            String line;
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }

            Log.d(TAG, "Result: " + result.toString());

        } catch (IOException e) {
            e.printStackTrace();
        }

        conn.disconnect();

        // try parse the string to a JSON object
        try {
            jsonObject = new JSONObject(result.toString());
        } catch (JSONException e) {
            Log.e(TAG, "Error parsing data " + e.toString());
        }

        // return JSON Object
        return jsonObject;
    }
}

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package com.zatackcoder.pushnotificationexample;

import android.util.Log;

import org.json.JSONException;

import org.json.JSONObject;

import java.io.BufferedInputStream;

import java.io.BufferedReader;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.UnsupportedEncodingException;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLEncoder;

import java.util.HashMap;

/**

* Created by rajesh kumar sahanee on 19/9/17.

public class JsonParser {

private final String TAG = "Json Parser";

private HttpURLConnection conn;

private final StringBuilder result = new StringBuilder();

private JSONObject jsonObject;

public JSONObject post(String url, HashMap<String, String> params, HashMap<String, String> files) {

try {

conn = (HttpURLConnection) new URL(url).openConnection();

conn.setDoInput(true);//Allow Inputs

conn.setDoOutput(true);//Allow Outputs

conn.setUseCaches(false);//Don't use a cached Copy

conn.setRequestMethod("POST");

conn.setRequestProperty("Connection", "Keep-Alive");

conn.setRequestProperty("Accept-Charset", "UTF-8");

conn.setReadTimeout(10000);

conn.setConnectTimeout(50000);

String boundary = "*****";

if (files != null) {

conn.setRequestProperty("ENCTYPE", "multipart/form-data");

conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

for (String key : files.keySet()) {

conn.setRequestProperty(key, files.get(key));

}

conn.connect();

DataOutputStream dataOutputStream = new DataOutputStream(conn.getOutputStream());

//file uploading

String twoHyphens = "--";

String lineEnd = "\r\n";

if (files != null) {

for (String key : files.keySet()) {

int bytesRead, bytesAvailable, bufferSize;

byte[] buffer;

int maxBufferSize = 1024 * 1024; //1 * 1024 * 1024

File selectedFile = new File(files.get(key));

if (!selectedFile.isFile()) {

break;

}

dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);

//writing bytes to data outputstream

dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"" + key + "\";filename=\"" + files.get(key) + "\"" + lineEnd);

dataOutputStream.writeBytes(lineEnd);

FileInputStream fileInputStream = new FileInputStream(selectedFile);

//returns no. of bytes present in fileInputStream

bytesAvailable = fileInputStream.available();

//selecting the buffer size as minimum of available bytes or 1 MB

bufferSize = Math.min(bytesAvailable, maxBufferSize);

//setting the buffer as byte array of size of bufferSize

buffer = new byte[bufferSize];

//reads bytes from FileInputStream(from 0th index of buffer to buffersize)

bytesRead = fileInputStream.read(buffer, 0, bufferSize);

//loop repeats till bytesRead = -1, i.e., no bytes are left to read

while (bytesRead > 0) {

//write the bytes read from inputstream

dataOutputStream.write(buffer, 0, bufferSize);

bytesAvailable = fileInputStream.available();

bufferSize = Math.min(bytesAvailable, maxBufferSize);

bytesRead = fileInputStream.read(buffer, 0, bufferSize);

}

dataOutputStream.writeBytes(lineEnd);

dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);

fileInputStream.close();

}

//parameters writing when file uploading

if (params != null && files != null) {

for (String key : params.keySet()) {

dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);

dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"" + key + "\"" + lineEnd);

dataOutputStream.writeBytes(lineEnd);

dataOutputStream.writeBytes(params.get(key));

dataOutputStream.writeBytes(lineEnd);

dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);

}

//parameters writing when no file uploading

else if (params != null) {

StringBuilder psb = new StringBuilder();

boolean flag = false;

for (String key : params.keySet()) {

try {

if (flag) {

psb.append("&");

}

psb.append(key).append("=").append(URLEncoder.encode(params.get(key), "UTF-8"));

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

}

flag = true;

}

dataOutputStream.writeBytes(psb.toString());

}

Log.d(TAG, "RC: " + conn.getResponseCode() + " RM: " + conn.getResponseMessage());

dataOutputStream.flush();

dataOutputStream.close();

} catch (IOException e) {

e.printStackTrace();

}

try {

//Receive the response from the server

BufferedReader reader = new BufferedReader(new InputStreamReader(new BufferedInputStream(conn.getInputStream())));

String line;

while ((line = reader.readLine()) != null) {

result.append(line);

}

Log.d(TAG, "Result: " + result.toString());

} catch (IOException e) {

e.printStackTrace();

}

conn.disconnect();

// try parse the string to a JSON object

try {

jsonObject = new JSONObject(result.toString());

} catch (JSONException e) {

Log.e(TAG, "Error parsing data " + e.toString());

}

// return JSON Object

return jsonObject;

}

public JSONObject get(String url, HashMap<String, String> params) {

StringBuilder psb = new StringBuilder();

boolean flag = false;

for (String key : params.keySet()) {

if (flag) {

psb.append("&");

}

try {

psb.append(key).append("=").append(URLEncoder.encode(params.get(key), "UTF-8"));

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

}

flag = true;

}

if (psb.length() != 0) {

url += "?" + psb.toString();

Log.d(TAG, "url: " + url);

}

try {

conn = (HttpURLConnection) new URL(url).openConnection();

conn.setDoOutput(false);

conn.setRequestMethod("GET");

conn.setRequestProperty("Accept-Charset", "UTF-8");

conn.setConnectTimeout(15000);

conn.connect();

} catch (IOException e) {

e.printStackTrace();

}

try {

//Receive the response from the server

BufferedReader reader = new BufferedReader(new InputStreamReader(new BufferedInputStream(conn.getInputStream())));

String line;

while ((line = reader.readLine()) != null) {

result.append(line);

}

Log.d(TAG, "Result: " + result.toString());

} catch (IOException e) {

e.printStackTrace();

}

conn.disconnect();

// try parse the string to a JSON object

try {

jsonObject = new JSONObject(result.toString());

} catch (JSONException e) {

Log.e(TAG, "Error parsing data " + e.toString());

}

// return JSON Object

return jsonObject;

}

MyFirebaseMessagingService.java

package com.zatackcoder.pushnotificationexample;

import android.annotation.SuppressLint;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.media.RingtoneManager;
import android.os.AsyncTask;
import android.os.Build;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.core.app.NotificationCompat;

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.HashMap;

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    private final String TAG = "MyFirebaseMessagingServ";

    @Override
    public void onNewToken(@NonNull String token) {
        Log.d(TAG, "Refreshed token: " + token);

        // If you want to send messages to this application instance or
        // manage this apps subscriptions on the server side, send the
        // Instance ID token to your app server.
        sendRegistrationToServer(token);
    }

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {

        String title = null;
        String content = null;
        HashMap<String, String> data = new HashMap<>();

        // TODO(developer): Handle FCM messages here.
        // Not getting messages here? See why this may be: https://goo.gl/39bRNJ
        Log.d(TAG, "From: " + remoteMessage.getFrom());

        // Check if message contains a notification payload.
        if (remoteMessage.getNotification() != null) {
            Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());

            title = remoteMessage.getNotification().getTitle();
            content = remoteMessage.getNotification().getBody();
        }

        // Check if message contains a data payload.
        if (remoteMessage.getData().size() > 0) {
            Log.d(TAG, "Message data payload: " + remoteMessage.getData());

            // Handle message within 10 seconds
            data = new HashMap<>(remoteMessage.getData());
        }

        // Also if you intend on generating your own notifications as a result of a received FCM
        // message, here is where that should be initiated. See sendNotification method below.
        sendNotification(title, content, data);
    }

    private void sendNotification(String title, String content, HashMap<String, String> data) {

        Intent intent = new Intent(getApplicationContext(), MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        for(String key : data.keySet()) intent.putExtra(key, data.get(key));
        PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "101";

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            @SuppressLint("WrongConstant") NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "Notification", NotificationManager.IMPORTANCE_MAX);

            //Configure Notification Channel
            notificationChannel.setDescription("ZataCoder Notification Channel");
            notificationChannel.enableLights(true);
            notificationChannel.setVibrationPattern(new long[]{0, 1000, 500, 1000});
            notificationChannel.enableVibration(true);

            notificationManager.createNotificationChannel(notificationChannel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID)
                .setSmallIcon(R.drawable.ic_notification)
                .setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher))
                .setContentTitle(title)
                .setAutoCancel(true)
                .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
                .setContentText(content)
                .setContentIntent(pendingIntent)
                .setWhen(System.currentTimeMillis())
                .setPriority(Notification.PRIORITY_MAX);


        notificationManager.notify(1, notificationBuilder.build());
    }

    private void sendRegistrationToServer(String token) {
        Log.d("TOKEN ", token);
        new FirebaseRegistrationAsyncTask(token).execute();
    }

    static class FirebaseRegistrationAsyncTask extends AsyncTask<Void, Void, Void> {

        final String token;

        FirebaseRegistrationAsyncTask(String token) {
            this.token = token;
        }

        @Override
        protected Void doInBackground(Void... voids) {
            HashMap<String, String> params = new HashMap<>();
            params.put("key", "TESTKEY");
            params.put("action", "register-device-token");
            params.put("topic", "android");
            params.put("token", token);

            JsonParser jsonParser = new JsonParser();
            //JSONObject jsonObject = jsonParser.post(Preferences.API_URL, params, null);
            JSONObject jsonObject = jsonParser.get("https://zatackcoder.com/demo/firebase-push-notification/register.php", params);
            if (jsonObject != null) {
                try {
                    //token saved to server
                    jsonObject.getString("results");
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void voids) {
            super.onPostExecute(voids);
        }
    }
}

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package com.zatackcoder.pushnotificationexample;

import android.annotation.SuppressLint;

import android.app.Notification;

import android.app.NotificationChannel;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.content.Context;

import android.content.Intent;

import android.graphics.BitmapFactory;

import android.media.RingtoneManager;

import android.os.AsyncTask;

import android.os.Build;

import android.util.Log;

import androidx.annotation.NonNull;

import androidx.core.app.NotificationCompat;

import com.google.firebase.messaging.FirebaseMessagingService;

import com.google.firebase.messaging.RemoteMessage;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.HashMap;

public class MyFirebaseMessagingService extends FirebaseMessagingService {

private final String TAG = "MyFirebaseMessagingServ";

@Override

public void onNewToken(@NonNull String token) {

Log.d(TAG, "Refreshed token: " + token);

// If you want to send messages to this application instance or

// manage this apps subscriptions on the server side, send the

// Instance ID token to your app server.

sendRegistrationToServer(token);

}

@Override

public void onMessageReceived(RemoteMessage remoteMessage) {

String title = null;

String content = null;

HashMap<String, String> data = new HashMap<>();

// TODO(developer): Handle FCM messages here.

// Not getting messages here? See why this may be: https://goo.gl/39bRNJ

Log.d(TAG, "From: " + remoteMessage.getFrom());

// Check if message contains a notification payload.

if (remoteMessage.getNotification() != null) {

Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());

title = remoteMessage.getNotification().getTitle();

content = remoteMessage.getNotification().getBody();

}

// Check if message contains a data payload.

if (remoteMessage.getData().size() > 0) {

Log.d(TAG, "Message data payload: " + remoteMessage.getData());

// Handle message within 10 seconds

data = new HashMap<>(remoteMessage.getData());

}

// Also if you intend on generating your own notifications as a result of a received FCM

// message, here is where that should be initiated. See sendNotification method below.

sendNotification(title, content, data);

}

private void sendNotification(String title, String content, HashMap<String, String> data) {

Intent intent = new Intent(getApplicationContext(), MainActivity.class);

intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);

for(String key : data.keySet()) intent.putExtra(key, data.get(key));

PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

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

String NOTIFICATION_CHANNEL_ID = "101";

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

@SuppressLint("WrongConstant") NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "Notification", NotificationManager.IMPORTANCE_MAX);

//Configure Notification Channel

notificationChannel.setDescription("ZataCoder Notification Channel");

notificationChannel.enableLights(true);

notificationChannel.setVibrationPattern(new long[]{0, 1000, 500, 1000});

notificationChannel.enableVibration(true);

notificationManager.createNotificationChannel(notificationChannel);

}

NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID)

.setSmallIcon(R.drawable.ic_notification)

.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher))

.setContentTitle(title)

.setAutoCancel(true)

.setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))

.setContentText(content)

.setContentIntent(pendingIntent)

.setWhen(System.currentTimeMillis())

.setPriority(Notification.PRIORITY_MAX);

notificationManager.notify(1, notificationBuilder.build());

}

private void sendRegistrationToServer(String token) {

Log.d("TOKEN ", token);

new FirebaseRegistrationAsyncTask(token).execute();

}

static class FirebaseRegistrationAsyncTask extends AsyncTask<Void, Void, Void> {

final String token;

FirebaseRegistrationAsyncTask(String token) {

this.token = token;

}

@Override

protected Void doInBackground(Void... voids) {

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

params.put("key", "TESTKEY");

params.put("action", "register-device-token");

params.put("topic", "android");

params.put("token", token);

JsonParser jsonParser = new JsonParser();

//JSONObject jsonObject = jsonParser.post(Preferences.API_URL, params, null);

JSONObject jsonObject = jsonParser.get("https://zatackcoder.com/demo/firebase-push-notification/register.php", params);

if (jsonObject != null) {

try {

//token saved to server

jsonObject.getString("results");

} catch (JSONException e) {

e.printStackTrace();

}

return null;

}

@Override

protected void onPostExecute(Void voids) {

super.onPostExecute(voids);

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.zatackcoder.pushnotificationexample">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".MyFirebaseMessagingService"
            android:enabled="true"
            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>

    </application>

</manifest>

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

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

package="com.zatackcoder.pushnotificationexample">

<application

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:roundIcon="@mipmap/ic_launcher_round"

android:supportsRtl="true"

android:theme="@style/AppTheme">

<intent-filter>

</intent-filter>

</activity>

<service

android:name=".MyFirebaseMessagingService"

android:enabled="true"

android:exported="false">

<intent-filter>

</intent-filter>

</service>

</application>

</manifest>

build.gradle (Project Level)

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

buildscript {
    
    repositories {
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.6.3'
        classpath 'com.google.gms:google-services:4.3.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

buildscript {

repositories {

google()

jcenter()

}

dependencies {

classpath 'com.android.tools.build:gradle:3.6.3'

classpath 'com.google.gms:google-services:4.3.3'

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

// in the individual module build.gradle files

}

build.gradle (App Level)

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

android {
    compileSdkVersion 28


    defaultConfig {
        applicationId "com.zatackcoder.pushnotificationexample"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    implementation 'com.google.firebase:firebase-messaging:20.1.5'
}