FirebaseInstanceId在2020年底被宣布将被废弃，因此建议使用FirebaseInstallations和FirebaseMessaging代替。FirebaseInstallations提供了生成和管理FIS IDs的能力，而FirebaseMessaging可用于发送消息到指定的应用程序实例。

以下是一个示例代码：

// Initialize FirebaseInstallations FirebaseInstallations.getInstance().getId() .addOnCompleteListener(new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if (task.isSuccessful()) { String fisId = task.getResult(); Log.d(TAG, "Firebase Installations ID: " + fisId); // Use the FIS ID to send messages to the app instance } else { Log.e(TAG, "Failed to get Firebase Installations ID", task.getException()); } } });

// Initialize FirebaseMessaging FirebaseMessaging.getInstance().getToken() .addOnCompleteListener(new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if (task.isSuccessful()) { String token = task.getResult(); Log.d(TAG, "Firebase Messaging Token: " + token); } else { Log.e(TAG, "Failed to get Firebase Messaging Token", task.getException()); } } });

可以在应用程序的build.gradle文件中添加以下依赖项：

implementation 'com.google.firebase:firebase-installations:17.0.0' implementation 'com.google.firebase:firebase-messaging:22.0.0'