php实现推送消息推送

PHP 实现消息推送的方法

使用 WebSocket 实现实时推送

WebSocket 是一种在单个 TCP 连接上进行全双工通信的协议，适用于实时消息推送。

安装 Ratchet 库（WebSocket 实现）：

composer require cboden/ratchet

创建 WebSocket 服务器：

use Ratchet\Server\IoServer;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;
use MyApp\Chat;

require dirname(__DIR__) . '/vendor/autoload.php';

$server = IoServer::factory(
    new HttpServer(
        new WsServer(
            new Chat()
        )
    ),
    8080
);

$server->run();

创建消息处理类：

namespace MyApp;
use Ratchet\MessageComponentInterface;
use Ratchet\ConnectionInterface;

class Chat implements MessageComponentInterface {
    protected $clients;

    public function __construct() {
        $this->clients = new \SplObjectStorage;
    }

    public function onOpen(ConnectionInterface $conn) {
        $this->clients->attach($conn);
    }

    public function onMessage(ConnectionInterface $from, $msg) {
        foreach ($this->clients as $client) {
            if ($from !== $client) {
                $client->send($msg);
            }
        }
    }

    public function onClose(ConnectionInterface $conn) {
        $this->clients->detach($conn);
    }

    public function onError(ConnectionInterface $conn, \Exception $e) {
        $conn->close();
    }
}

使用 Server-Sent Events (SSE)

SSE 是一种服务器向浏览器推送消息的简单方式。

服务端实现：

header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
header('Connection: keep-alive');

function sendMsg($id, $msg) {
    echo "id: $id" . PHP_EOL;
    echo "data: $msg" . PHP_EOL;
    echo PHP_EOL;
    ob_flush();
    flush();
}

while(true) {
    $serverTime = time();
    sendMsg($serverTime, 'server time: ' . date("h:i:s", $serverTime));
    sleep(1);
}

客户端实现：

var evtSource = new EventSource("sse.php");
evtSource.onmessage = function(e) {
    console.log(e.data);
};

使用第三方推送服务

Firebase Cloud Messaging (FCM) 是流行的推送解决方案。

发送 FCM 通知：

function sendFCM($token, $title, $body) {
    $url = 'https://fcm.googleapis.com/fcm/send';
    $serverKey = 'YOUR_SERVER_KEY';

    $notification = [
        'title' => $title,
        'body' => $body,
        'icon' => 'icon',
        'sound' => 'default'
    ];

    $fields = [
        'to' => $token,
        'notification' => $notification,
        'priority' => 'high'
    ];

    $headers = [
        'Authorization: key=' . $serverKey,
        'Content-Type: application/json'
    ];

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($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($fields));
    $result = curl_exec($ch);
    curl_close($ch);

    return $result;
}

使用 AJAX 长轮询

长轮询是传统轮询的改进版本，服务器在有数据时才响应。

服务端实现：

// wait.php
$data = getNewData(); // 自定义获取新数据函数
while (empty($data)) {
    usleep(100000); // 100ms
    $data = getNewData();
    if (connection_aborted()) {
        exit;
    }
}

echo json_encode($data);

客户端实现：

function longPoll() {
    fetch('wait.php')
        .then(response => response.json())
        .then(data => {
            console.log(data);
            longPoll();
        });
}
longPoll();

使用消息队列

对于高并发场景，可以使用 RabbitMQ 等消息队列。

安装 PHP AMQP 扩展：

pecl install amqp

发送消息示例：

$connection = new AMQPConnection([
    'host' => 'localhost',
    'port' => 5672,
    'login' => 'guest',
    'password' => 'guest'
]);
$connection->connect();

$channel = new AMQPChannel($connection);
$exchange = new AMQPExchange($channel);
$exchange->setName('notifications');
$exchange->setType(AMQP_EX_TYPE_FANOUT);
$exchange->declareExchange();

$exchange->publish(json_encode(['message' => 'Hello']), '');

接收消息示例：

$queue = new AMQPQueue($channel);
$queue->setName('notification_queue');
$queue->declareQueue();
$queue->bind('notifications', '');

$queue->consume(function($envelope, $queue) {
    $message = json_decode($envelope->getBody(), true);
    // 处理消息
    $queue->ack($envelope->getDeliveryTag());
});

每种方法适用于不同场景：WebSocket 适合实时双向通信，SSE 适合服务器到客户端的单向推送，FCM 适合移动端推送，长轮询适合简单实现，消息队列适合高并发分布式系统。根据具体需求选择最合适的方案。