基於發布/訂閱模型,FCM 主題消息傳遞允許您向已選擇加入特定主題的多個設備發送消息。您可以根據需要撰寫主題消息,FCM 負責處理路由並將消息可靠地傳遞到正確的設備。
例如,本地潮汐預報應用程序的用戶可以選擇“潮汐流警報”主題並接收指定區域最佳鹹水捕魚條件的通知。體育應用程序的用戶可以為他們最喜歡的球隊訂閱實時比賽比分的自動更新。
有關主題的一些注意事項:
- 主題消息最適合天氣或其他公開信息等內容。
- 主題消息針對吞吐量而不是延遲進行了優化。為了快速、安全地傳送到單個設備或一小組設備,將消息定位到註冊令牌,而不是主題。
- 如果您需要向每個用戶的多個設備發送消息,請考慮針對這些用例的設備組消息傳遞。
- 主題消息支持對每個主題的無限訂閱。但是,FCM 在這些方面實施了限制:
- 一個應用實例可以訂閱不超過 2000 個主題。
- 如果您使用批量導入訂閱應用實例,則每個請求限制為 1000 個應用實例。
- 新訂閱的頻率受每個項目的速率限制。如果您在短時間內發送過多的訂閱請求,FCM 服務器將響應
429 RESOURCE_EXHAUSTED
(“超出配額”)響應。使用指數退避重試。
為客戶端應用程序訂閱主題
客戶端應用程序可以訂閱任何現有主題,也可以創建新主題。當客戶端應用程序訂閱一個新主題名稱(您的 Firebase 項目尚不存在的主題名稱)時,將在 FCM 中創建一個具有該名稱的新主題,隨後任何客戶端都可以訂閱它。
要訂閱主題,客戶端應用程序使用 FCM 主題名稱調用 Firebase Cloud Messaging subscribeToTopic()
。此方法返回一個Task
,完成偵聽器可以使用它來確定訂閱是否成功:
Kotlin+KTX
Firebase.messaging.subscribeToTopic("weather") .addOnCompleteListener { task -> var msg = "Subscribed" if (!task.isSuccessful) { msg = "Subscribe failed" } Log.d(TAG, msg) Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show() }
Java
FirebaseMessaging.getInstance().subscribeToTopic("weather") .addOnCompleteListener(new OnCompleteListener<Void>() { @Override public void onComplete(@NonNull Task<Void> task) { String msg = "Subscribed"; if (!task.isSuccessful()) { msg = "Subscribe failed"; } Log.d(TAG, msg); Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show(); } });
要取消訂閱,客戶端應用程序使用主題名稱調用 Firebase Cloud Messaging unsubscribeFromTopic()
。
在服務器上管理主題訂閱
Firebase Admin SDK允許您從服務器端執行基本的主題管理任務。鑑於他們的註冊令牌,您可以使用服務器邏輯批量訂閱和取消訂閱客戶端應用程序實例。
您可以將客戶端應用程序實例訂閱到任何現有主題,也可以創建新主題。當您使用 API 為客戶端應用程序訂閱一個新主題(您的 Firebase 項目尚不存在的主題)時,將在 FCM 中創建一個同名的新主題,隨後任何客戶端都可以訂閱它。
您可以將註冊令牌列表傳遞給 Firebase Admin SDK 訂閱方法,以便為相應的設備訂閱主題:
節點.js
// These registration tokens come from the client FCM SDKs.
const registrationTokens = [
'YOUR_REGISTRATION_TOKEN_1',
// ...
'YOUR_REGISTRATION_TOKEN_n'
];
// Subscribe the devices corresponding to the registration tokens to the
// topic.
getMessaging().subscribeToTopic(registrationTokens, topic)
.then((response) => {
// See the MessagingTopicManagementResponse reference documentation
// for the contents of response.
console.log('Successfully subscribed to topic:', response);
})
.catch((error) => {
console.log('Error subscribing to topic:', error);
});
爪哇
// These registration tokens come from the client FCM SDKs.
List<String> registrationTokens = Arrays.asList(
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n"
);
// Subscribe the devices corresponding to the registration tokens to the
// topic.
TopicManagementResponse response = FirebaseMessaging.getInstance().subscribeToTopic(
registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
System.out.println(response.getSuccessCount() + " tokens were subscribed successfully");
Python
# These registration tokens come from the client FCM SDKs.
registration_tokens = [
'YOUR_REGISTRATION_TOKEN_1',
# ...
'YOUR_REGISTRATION_TOKEN_n',
]
# Subscribe the devices corresponding to the registration tokens to the
# topic.
response = messaging.subscribe_to_topic(registration_tokens, topic)
# See the TopicManagementResponse reference documentation
# for the contents of response.
print(response.success_count, 'tokens were subscribed successfully')
去
// These registration tokens come from the client FCM SDKs.
registrationTokens := []string{
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n",
}
// Subscribe the devices corresponding to the registration tokens to the
// topic.
response, err := client.SubscribeToTopic(ctx, registrationTokens, topic)
if err != nil {
log.Fatalln(err)
}
// See the TopicManagementResponse reference documentation
// for the contents of response.
fmt.Println(response.SuccessCount, "tokens were subscribed successfully")
C#
// These registration tokens come from the client FCM SDKs.
var registrationTokens = new List<string>()
{
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n",
};
// Subscribe the devices corresponding to the registration tokens to the
// topic
var response = await FirebaseMessaging.DefaultInstance.SubscribeToTopicAsync(
registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
Console.WriteLine($"{response.SuccessCount} tokens were subscribed successfully");
Admin FCM API 還允許您通過將註冊令牌傳遞給適當的方法來取消訂閱設備的主題:
節點.js
// These registration tokens come from the client FCM SDKs.
const registrationTokens = [
'YOUR_REGISTRATION_TOKEN_1',
// ...
'YOUR_REGISTRATION_TOKEN_n'
];
// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
getMessaging().unsubscribeFromTopic(registrationTokens, topic)
.then((response) => {
// See the MessagingTopicManagementResponse reference documentation
// for the contents of response.
console.log('Successfully unsubscribed from topic:', response);
})
.catch((error) => {
console.log('Error unsubscribing from topic:', error);
});
爪哇
// These registration tokens come from the client FCM SDKs.
List<String> registrationTokens = Arrays.asList(
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n"
);
// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
TopicManagementResponse response = FirebaseMessaging.getInstance().unsubscribeFromTopic(
registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
System.out.println(response.getSuccessCount() + " tokens were unsubscribed successfully");
Python
# These registration tokens come from the client FCM SDKs.
registration_tokens = [
'YOUR_REGISTRATION_TOKEN_1',
# ...
'YOUR_REGISTRATION_TOKEN_n',
]
# Unubscribe the devices corresponding to the registration tokens from the
# topic.
response = messaging.unsubscribe_from_topic(registration_tokens, topic)
# See the TopicManagementResponse reference documentation
# for the contents of response.
print(response.success_count, 'tokens were unsubscribed successfully')
去
// These registration tokens come from the client FCM SDKs.
registrationTokens := []string{
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n",
}
// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
response, err := client.UnsubscribeFromTopic(ctx, registrationTokens, topic)
if err != nil {
log.Fatalln(err)
}
// See the TopicManagementResponse reference documentation
// for the contents of response.
fmt.Println(response.SuccessCount, "tokens were unsubscribed successfully")
C#
// These registration tokens come from the client FCM SDKs.
var registrationTokens = new List<string>()
{
"YOUR_REGISTRATION_TOKEN_1",
// ...
"YOUR_REGISTRATION_TOKEN_n",
};
// Unsubscribe the devices corresponding to the registration tokens from the
// topic
var response = await FirebaseMessaging.DefaultInstance.UnsubscribeFromTopicAsync(
registrationTokens, topic);
// See the TopicManagementResponse reference documentation
// for the contents of response.
Console.WriteLine($"{response.SuccessCount} tokens were unsubscribed successfully");
subscribeToTopic()
和unsubscribeFromTopic()
方法生成一個包含來自 FCM 的響應的對象。無論請求中指定的註冊令牌數量如何,返回類型都具有相同的格式。
如果出現錯誤(身份驗證失敗、無效令牌或主題等),這些方法會導致錯誤。有關錯誤代碼的完整列表,包括描述和解決步驟,請參閱管理 FCM API 錯誤。
接收和處理主題消息
FCM 以與其他下游消息相同的方式傳遞主題消息。
要接收消息,請使用擴展FirebaseMessagingService服務。您的服務應該覆蓋onMessageReceived
和onDeletedMessages
回調。它應該在收到消息後的 20 秒內處理任何消息(在 Android Marshmallow 上為 10 秒)。時間窗口可能會更短,具體取決於調用onMessageReceived
之前發生的操作系統延遲。在那之後,各種操作系統行為(例如 Android O 的後台執行限制)可能會干擾您完成工作的能力。有關詳細信息,請參閱我們對消息優先級的概述。
onMessageReceived
為大多數消息類型提供,但以下情況除外:
當您的應用程序處於後台時發送的通知消息。在這種情況下,通知將傳送到設備的系統托盤。默認情況下,用戶點擊通知會打開應用程序啟動器。
在後台接收時同時具有通知和數據負載的消息。在這種情況下,通知會傳送到設備的系統托盤,數據負載會在啟動器 Activity 的 intent 的附加項中傳送。
總之:
應用狀態 | 通知 | 數據 | 兩個都 |
---|---|---|---|
前景 | onMessageReceived | onMessageReceived | onMessageReceived |
背景 | 系統托盤 | onMessageReceived | 通知:系統托盤 數據:在意圖的附加值中。 |
編輯應用程序清單
要使用FirebaseMessagingService
,您需要在應用清單中添加以下內容:
<service android:name=".java.MyFirebaseMessagingService" android:exported="false"> <intent-filter> <action android:name="com.google.firebase.MESSAGING_EVENT" /> </intent-filter> </service>
此外,建議您設置默認值以自定義通知的外觀。您可以指定自定義默認圖標和自定義默認顏色,只要通知負載中未設置等效值,就會應用這些圖標和自定義默認顏色。
在application
標籤內添加這些行以設置自定義默認圖標和自定義顏色:
<!-- Set custom default icon. This is used when no icon is set for incoming notification messages. See README(https://goo.gl/l4GJaQ) for more. --> <meta-data android:name="com.google.firebase.messaging.default_notification_icon" android:resource="@drawable/ic_stat_ic_notification" /> <!-- Set color used with incoming notification messages. This is used when no color is set for the incoming notification message. See README(https://goo.gl/6BKBk7) for more. --> <meta-data android:name="com.google.firebase.messaging.default_notification_color" android:resource="@color/colorAccent" />
Android 顯示自定義默認圖標
- 從Notifications composer發送的所有通知消息。
- 任何未在通知負載中明確設置圖標的通知消息。
Android 使用自定義默認顏色
- 從Notifications composer發送的所有通知消息。
- 任何未在通知負載中明確設置顏色的通知消息。
如果未設置自定義默認圖標並且在通知有效負載中也未設置圖標,Android 會顯示呈現為白色的應用程序圖標。
覆蓋onMessageReceived
通過覆蓋FirebaseMessagingService.onMessageReceived
方法,您可以根據接收到的RemoteMessage對象執行操作並獲取消息數據:
Kotlin+KTX
override fun onMessageReceived(remoteMessage: RemoteMessage) { // TODO(developer): Handle FCM messages here. // Not getting messages here? See why this may be: https://goo.gl/39bRNJ Log.d(TAG, "From: ${remoteMessage.from}") // Check if message contains a data payload. if (remoteMessage.data.isNotEmpty()) { Log.d(TAG, "Message data payload: ${remoteMessage.data}") // Check if data needs to be processed by long running job if (needsToBeScheduled()) { // For long-running tasks (10 seconds or more) use WorkManager. scheduleJob() } else { // Handle message within 10 seconds handleNow() } } // Check if message contains a notification payload. remoteMessage.notification?.let { Log.d(TAG, "Message Notification Body: ${it.body}") } // 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. }
Java
@Override public void onMessageReceived(RemoteMessage remoteMessage) { // 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 data payload. if (remoteMessage.getData().size() > 0) { Log.d(TAG, "Message data payload: " + remoteMessage.getData()); if (/* Check if data needs to be processed by long running job */ true) { // For long-running tasks (10 seconds or more) use WorkManager. scheduleJob(); } else { // Handle message within 10 seconds handleNow(); } } // Check if message contains a notification payload. if (remoteMessage.getNotification() != null) { Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody()); } // 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. }
覆蓋onDeletedMessages
在某些情況下,FCM 可能不會傳遞消息。如果連接時特定設備上的應用程序有太多待處理的消息 (>100),或者如果該設備超過一個月未連接到 FCM,就會發生這種情況。在這些情況下,您可能會收到FirebaseMessagingService.onDeletedMessages()
的回調當應用實例收到此回調時,它應該與您的應用服務器執行完全同步。如果您在過去 4 週內沒有向該設備上的應用發送消息,FCM 將不會調用onDeletedMessages()
。在後台應用程序中處理通知消息
當您的應用程序處於後台時,Android 會將通知消息定向到系統托盤。默認情況下,用戶點擊通知會打開應用程序啟動器。
這包括包含通知和數據負載的消息(以及從通知控制台發送的所有消息)。在這些情況下,通知會傳送到設備的系統托盤,並且數據負載會在啟動器 Activity 的 intent 的附加項中傳送。
要深入了解向您的應用程序發送的消息,請參閱FCM 報告儀表板,它記錄了在 Apple 和 Android 設備上發送和打開的消息數量,以及 Android 應用程序的“印象”(用戶看到的通知)數據。
構建發送請求
創建主題後,通過在客戶端訂閱客戶端應用程序實例或通過服務器 API訂閱主題,您可以向主題發送消息。如果這是您第一次為 FCM 構建發送請求,請參閱您的服務器環境和 FCM指南,了解重要的背景和設置信息。
在後端的發送邏輯中,指定所需的主題名稱,如下所示:
節點.js
// The topic name can be optionally prefixed with "/topics/".
const topic = 'highScores';
const message = {
data: {
score: '850',
time: '2:45'
},
topic: topic
};
// Send a message to devices subscribed to the provided topic.
getMessaging().send(message)
.then((response) => {
// Response is a message ID string.
console.log('Successfully sent message:', response);
})
.catch((error) => {
console.log('Error sending message:', error);
});
爪哇
// The topic name can be optionally prefixed with "/topics/".
String topic = "highScores";
// See documentation on defining a message payload.
Message message = Message.builder()
.putData("score", "850")
.putData("time", "2:45")
.setTopic(topic)
.build();
// Send a message to the devices subscribed to the provided topic.
String response = FirebaseMessaging.getInstance().send(message);
// Response is a message ID string.
System.out.println("Successfully sent message: " + response);
Python
# The topic name can be optionally prefixed with "/topics/".
topic = 'highScores'
# See documentation on defining a message payload.
message = messaging.Message(
data={
'score': '850',
'time': '2:45',
},
topic=topic,
)
# Send a message to the devices subscribed to the provided topic.
response = messaging.send(message)
# Response is a message ID string.
print('Successfully sent message:', response)
去
// The topic name can be optionally prefixed with "/topics/".
topic := "highScores"
// See documentation on defining a message payload.
message := &messaging.Message{
Data: map[string]string{
"score": "850",
"time": "2:45",
},
Topic: topic,
}
// Send a message to the devices subscribed to the provided topic.
response, err := client.Send(ctx, message)
if err != nil {
log.Fatalln(err)
}
// Response is a message ID string.
fmt.Println("Successfully sent message:", response)
C#
// The topic name can be optionally prefixed with "/topics/".
var topic = "highScores";
// See documentation on defining a message payload.
var message = new Message()
{
Data = new Dictionary<string, string>()
{
{ "score", "850" },
{ "time", "2:45" },
},
Topic = topic,
};
// Send a message to the devices subscribed to the provided topic.
string response = await FirebaseMessaging.DefaultInstance.SendAsync(message);
// Response is a message ID string.
Console.WriteLine("Successfully sent message: " + response);
休息
POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
"message":{
"topic" : "foo-bar",
"notification" : {
"body" : "This is a Firebase Cloud Messaging Topic Message!",
"title" : "FCM Message"
}
}
}
捲曲命令:
curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
"message": {
"topic" : "foo-bar",
"notification": {
"body": "This is a Firebase Cloud Messaging Topic Message!",
"title": "FCM Message"
}
}
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
要向主題組合發送消息,請指定condition ,它是指定目標主題的布爾表達式。例如,以下條件會將消息發送到訂閱了TopicA
和TopicB
或TopicC
的設備:
"'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)"
FCM 首先計算括號中的任何條件,然後從左到右計算表達式。在上面的表達式中,訂閱任何單個主題的用戶不會收到消息。同樣,未訂閱TopicA
用戶也不會收到消息。這些組合確實收到了它:
-
TopicA
和TopicB
-
TopicA
和TopicC
您最多可以在條件表達式中包含五個主題。
發送到一個條件:
節點.js
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
const condition = '\'stock-GOOG\' in topics || \'industry-tech\' in topics';
// See documentation on defining a message payload.
const message = {
notification: {
title: '$FooCorp up 1.43% on the day',
body: '$FooCorp gained 11.80 points to close at 835.67, up 1.43% on the day.'
},
condition: condition
};
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
getMessaging().send(message)
.then((response) => {
// Response is a message ID string.
console.log('Successfully sent message:', response);
})
.catch((error) => {
console.log('Error sending message:', error);
});
爪哇
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
String condition = "'stock-GOOG' in topics || 'industry-tech' in topics";
// See documentation on defining a message payload.
Message message = Message.builder()
.setNotification(Notification.builder()
.setTitle("$GOOG up 1.43% on the day")
.setBody("$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.")
.build())
.setCondition(condition)
.build();
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
String response = FirebaseMessaging.getInstance().send(message);
// Response is a message ID string.
System.out.println("Successfully sent message: " + response);
Python
# Define a condition which will send to devices which are subscribed
# to either the Google stock or the tech industry topics.
condition = "'stock-GOOG' in topics || 'industry-tech' in topics"
# See documentation on defining a message payload.
message = messaging.Message(
notification=messaging.Notification(
title='$GOOG up 1.43% on the day',
body='$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.',
),
condition=condition,
)
# Send a message to devices subscribed to the combination of topics
# specified by the provided condition.
response = messaging.send(message)
# Response is a message ID string.
print('Successfully sent message:', response)
去
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
condition := "'stock-GOOG' in topics || 'industry-tech' in topics"
// See documentation on defining a message payload.
message := &messaging.Message{
Data: map[string]string{
"score": "850",
"time": "2:45",
},
Condition: condition,
}
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
response, err := client.Send(ctx, message)
if err != nil {
log.Fatalln(err)
}
// Response is a message ID string.
fmt.Println("Successfully sent message:", response)
C#
// Define a condition which will send to devices which are subscribed
// to either the Google stock or the tech industry topics.
var condition = "'stock-GOOG' in topics || 'industry-tech' in topics";
// See documentation on defining a message payload.
var message = new Message()
{
Notification = new Notification()
{
Title = "$GOOG up 1.43% on the day",
Body = "$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.",
},
Condition = condition,
};
// Send a message to devices subscribed to the combination of topics
// specified by the provided condition.
string response = await FirebaseMessaging.DefaultInstance.SendAsync(message);
// Response is a message ID string.
Console.WriteLine("Successfully sent message: " + response);
休息
POST https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
Content-Type: application/json
Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA
{
"message":{
"condition": "'dogs' in topics || 'cats' in topics",
"notification" : {
"body" : "This is a Firebase Cloud Messaging Topic Message!",
"title" : "FCM Message",
}
}
}
捲曲命令:
curl -X POST -H "Authorization: Bearer ya29.ElqKBGN2Ri_Uz...HnS_uNreA" -H "Content-Type: application/json" -d '{
"notification": {
"title": "FCM Message",
"body": "This is a Firebase Cloud Messaging Topic Message!",
},
"condition": "'dogs' in topics || 'cats' in topics"
}' https://fcm.googleapis.com/v1/projects/myproject-b5ae1/messages:send HTTP/1.1
下一步
- 詳細了解另一種發送到多個設備的方式——設備群組消息