这个链接的解决方案对我帮助很大。你可以去看看。

带有这些指令行的curl.php文件可以工作。

<?php 
// Server key from Firebase Console define( 'API_ACCESS_KEY', 'AAAA----FE6F' );
$data = array("to" => "cNf2---6Vs9", "notification" => array( "title" => "Shareurcodes.com", "body" => "A Code Sharing Blog!","icon" => "icon.png", "click_action" => "http://shareurcodes.com"));
$data_string = json_encode($data);
echo "The Json Data : ".$data_string;
$headers = array ( 'Authorization: key=' . API_ACCESS_KEY, 'Content-Type: application/json' );
$ch = curl_init(); curl_setopt( $ch,CURLOPT_URL, 'https://fcm.googleapis.com/fcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_POSTFIELDS, $data_string);
$result = curl_exec($ch);
curl_close ($ch);
echo "<p>&nbsp;</p>";
echo "The Result : ".$result;

请记住，您需要使用另一个浏览器执行curl.php文件，而不是从用于获取用户令牌的浏览器执行。只有在浏览其他网站时才能看到通知。

Go to cloud Messaging select:  Server key



function sendGCM($message, $deviceToken) {

    $url = 'https://fcm.googleapis.com/fcm/send';
    $fields = array (
            'registration_ids' => array (
                $id
            ),
            'data' => array (
                "title" =>  "Notification title",
                "body" =>  $message,
            )
    );
    $fields = json_encode ( $fields );
    $headers = array (
        'Authorization: key=' . "YOUR_SERVER_KEY",
        '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_POSTFIELDS, $fields );
    $result = curl_exec ( $ch );
    echo $result;

    curl_close ($ch);
}

使用服务api。

URL: https://fcm.googleapis.com/fcm/send

方法类型:POST

标题:

Content-Type: application/json
Authorization: key=your api key

车身/有效载荷：

{
   "notification": {
      "title": "Your Title",
      "text": "Your Text",
      "click_action": "OPEN_ACTIVITY_1"
   },
   "data": {
      "<some_key>": "<some_value>"
   },
   "to": "<device_token>"
}

在你的应用程序中，你可以添加以下代码在你的活动中被调用:

<intent-filter>
    <action android:name="OPEN_ACTIVITY_1" />
    <category android:name="android.intent.category.DEFAULT" />
</intent-filter>

也检查答案在Firebase onmessagerreceived未调用时，应用程序在后台

例如，您可以使用用于谷歌云消息传递(GCM)的PHP脚本。Firebase及其控制台位于GCM之上。

我在github上找到了这个: https://gist.github.com/prime31/5675017

提示:这个PHP脚本会产生一个android通知。

因此:如果你想在Android中接收和显示通知，请阅读来自Koot的回答。

首先，你需要从android获得一个令牌，然后你可以调用这个php代码，你甚至可以在你的应用程序中为进一步的操作发送数据。

 <?php

// Call .php?Action=M&t=title&m=message&r=token
$action=$_GET["Action"];


switch ($action) {
    Case "M":
         $r=$_GET["r"];
        $t=$_GET["t"];
        $m=$_GET["m"];

        $j=json_decode(notify($r, $t, $m));

        $succ=0;
        $fail=0;

        $succ=$j->{'success'};
        $fail=$j->{'failure'};

        print "Success: " . $succ . "<br>";
        print "Fail   : " . $fail . "<br>";

        break;


default:
        print json_encode ("Error: Function not defined ->" . $action);
}

function notify ($r, $t, $m)
    {
    // API access key from Google API's Console
        if (!defined('API_ACCESS_KEY')) define( 'API_ACCESS_KEY', 'Insert here' );
        $tokenarray = array($r);
        // prep the bundle
        $msg = array
        (
            'title'     => $t,
            'message'     => $m,
           'MyKey1'       => 'MyData1',
            'MyKey2'       => 'MyData2', 

        );
        $fields = array
        (
            'registration_ids'     => $tokenarray,
            'data'            => $msg
        );

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

        $ch = curl_init();
        curl_setopt( $ch,CURLOPT_URL, 'fcm.googleapis.com/fcm/send' );
        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;
    }


?>

如果你想从android发送推送通知，请查看我的博客文章

发送推送通知从一个android手机到另一个没有服务器。

发送推送通知只不过是发送到https://fcm.googleapis.com/fcm/send的请求

使用volley的代码片段:

    JSONObject json = new JSONObject();
 try {
 JSONObject userData=new JSONObject();
 userData.put("title","your title");
 userData.put("body","your body");

json.put("data",userData);
json.put("to", receiverFirebaseToken);
 }
 catch (JSONException e) {
 e.printStackTrace();
 }

JsonObjectRequest jsonObjectRequest = new JsonObjectRequest("https://fcm.googleapis.com/fcm/send", json, new Response.Listener<JSONObject>() {
 @Override
 public void onResponse(JSONObject response) {

Log.i("onResponse", "" + response.toString());
 }
 }, new Response.ErrorListener() {
 @Override
 public void onErrorResponse(VolleyError error) {

}
 }) {
 @Override
 public Map<String, String> getHeaders() throws AuthFailureError {

Map<String, String> params = new HashMap<String, String>();
 params.put("Authorizationey=" + SERVER_API_KEY);
 params.put("Content-Typepplication/json");
 return params;
 }
 };
 MySingleton.getInstance(context).addToRequestQueue(jsonObjectRequest);

我建议你们都去看看我的博客以获得完整的细节。