Spring Boot + Flutter Push Notification

[uniquejava]

有三个topic要谈：

1. sending push notification to a topic
2. directly to the users’ device
3. sending messages with additional data payload.

消息格式： https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages

pom.xml

<dependency>
 <groupId>com.google.firebase</groupId>
 <artifactId>firebase-admin</artifactId>
 <version>6.13.0</version>
</dependency>

最新版本请参见： https://firebase.google.com/docs/admin/setup#add-sdk

Authenticate a service account and authorize it to access Firebase services

you must generate a private key file in JSON format.

To generate a private key file for your service account:

In the Firebase console, open Settings > Service Accounts.

Click Generate New Private Key, then confirm by clicking Generate Key.

Securely store the JSON file containing the key.

使用以上json文件初始化FCM Admin SDK

FileInputStream serviceAccount =
 new FileInputStream("path/to/serviceAccountKey.json");

FirebaseOptions options = new FirebaseOptions.Builder()
 .setCredentials(GoogleCredentials.fromStream(serviceAccount))
 .setDatabaseUrl("https://<DATABASE_NAME>.firebaseio.com")
 .build();

FirebaseApp.initializeApp(options);

如果是通过设置环境变量 GOOGLE_APPLICATION_CREDENTIALS

指定json文件的位置， 则以上代码修改为：

FirebaseOptions options = new FirebaseOptions.Builder()
 .setCredentials(GoogleCredentials.getApplicationDefault())
 .setDatabaseUrl("https://<DATABASE_NAME>.firebaseio.com/")
 .build();

FirebaseApp.initializeApp(options);

例子: export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/service-account-file.json"

或者使用以上json文件得到一个short-lived JWT token

private static String getAccessToken() throws IOException {
 GoogleCredential googleCredential = GoogleCredential
 .fromStream(new FileInputStream("service-account.json"))
 .createScoped(Arrays.asList(SCOPES));
 googleCredential.refreshToken();
 return googleCredential.getAccessToken();
}

如果要使用FCM service， SCOPES的值必须为 https://www.googleapis.com/auth/firebase.messaging

使用JWT Token

headers: {
 'Authorization': 'Bearer ' + accessToken
}

以上整理自： https://firebase.google.com/docs/cloud-messaging/auth-server

搭建FCM Server的要求

https://firebase.google.com/docs/cloud-messaging/server#role

搭建FCM Server的两种方式

1. FCM HTTP v1 API
2. Firebase Admin SDK for FCM （封装了FCM HTTP v1 API）

发送消息 (cyper实战)

public interface FcmService {

 /**
 * 发送消息到指定设备.
 * 
 * @param deviceToken 设备Token
 * @param title 标题
 * @param body 内容
 * @param payload 其他额外参数
 * @throws FirebaseMessagingException
 */
 void sendTokenMessage(String deviceToken, String title, String body, Map<String, String> payload)
 throws FirebaseMessagingException;

 /**
 * 发送topic.
 * 
 * @param topic 主题
 * @param title 标题
 * @param body 内容
 * @param payload 其他额外参数
 * @throws FirebaseMessagingException
 */
 void sendTopicMessage(String topic, String title, String body, Map<String, String> payload)
 throws FirebaseMessagingException;

 /**
 * 群发消息到多个设备
 * 
 * @param deviceTokens 多个设备的Token
 * @param title 标题
 * @param body 内容
 * @param payload 其他额外参数
 * @throws FirebaseMessagingException
 */
 void sendMessage2MultiDevices(List<String> deviceTokens, String title, String body, Map<String, String> payload)
 throws FirebaseMessagingException;

}

@Service
@Slf4j
public class FcmServiceImpl implements FcmService {
 @Override
 public void sendTokenMessage(String deviceToken, String title, String body, Map<String, String> payload)
 throws FirebaseMessagingException {
 sendMessage(deviceToken, title, body, payload, false);
 }

 @Override
 public void sendTopicMessage(String topic, String title, String body, Map<String, String> payload)
 throws FirebaseMessagingException {

 sendMessage(topic, title, body, payload, true);
 }

 private void sendMessage(String topicOrToken, String title, String body, Map<String, String> payload,
 boolean isTopic) throws FirebaseMessagingException {
 // See documentation on defining a message payload.
 Builder builder = Notification.builder();
 builder.setTitle(title);
 builder.setBody(body);
 Notification notification = builder.build();

 Message.Builder messageBuilder = Message.builder().setNotification(notification);

 if (payload != null) {
 messageBuilder.putAllData(payload);
 }

 if (isTopic) {
 messageBuilder.setTopic(topicOrToken);
 } else {
 messageBuilder.setToken(topicOrToken);
 }

 // Send a message to the device corresponding to the provided registration
 // token.

 String response = FirebaseMessaging.getInstance().send(messageBuilder.build());

 if (log.isInfoEnabled()) {
 log.info(response);
 }
 }

 @Override
 public void sendMessage2MultiDevices(List<String> deviceTokens, String title, String body,
 Map<String, String> payload) throws FirebaseMessagingException {
 Builder builder = Notification.builder();
 builder.setTitle(title);
 builder.setBody(body);
 Notification notification = builder.build();

 // @formatter:off
 
 MulticastMessage.Builder messageBuilder = MulticastMessage.builder()
 .setNotification(notification)
 .addAllTokens(deviceTokens);
 
 if(payload != null) {
 messageBuilder.putAllData(payload);
 }
 
 // @formatter:on

 BatchResponse response = FirebaseMessaging.getInstance().sendMulticast(messageBuilder.build());

 if (log.isInfoEnabled()) {
 log.info(response.getSuccessCount() + " messages were sent successfully");
 }

 }

}

App端 用到的 Dart package (pub spec)

Pub Spec: firebase_messaging 6.0.13

References

Spring Boot: Send push notifications from Spring Boot server-side application using FCM

新鲜出炉的：Flutter Push Notifications using flutter firebase messaging with example

Concise: FCM Push Notifications for Flutter

FilledStacks: Push Notifications in Flutter using Firebase

[uniquejava]

测试（device token || topic )

通过REST API在线发： https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages/send
（topic 和 token都行！）

通过firebase console发 （topic 和 token和user segment!）