从GCM迁移至FCM后，多Sender ID获取Token是否需修改？求最小代码改动

Great question—this is a super common concern when migrating from GCM to FCM, especially when you want to avoid rewriting chunks of existing code. Let’s cut to the chase:

Yes, you can absolutely keep using the comma-separated Sender ID pattern in FCM to get a single token that works with all your specified Sender IDs. This lets you keep your code almost identical to the GCM version, minimizing changes.

Here’s the FCM equivalent of your original code: #

String senderIds = "112233445566,889922338899";
String token = FirebaseInstanceId.getInstance().getToken(senderIds, FirebaseMessaging.INSTANCE_ID_SCOPE);

Compare this to your original GCM implementation:

String senderIds = "112233445566,889922338899";
String token = instanceID.getToken(senderIds, GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);

The only tiny adjustments you need to make are:

• Replace the GCM instanceID with FCM’s FirebaseInstanceId.getInstance() (the modern equivalent of GCM’s Instance ID)
• Swap GoogleCloudMessaging.INSTANCE_ID_SCOPE with FirebaseMessaging.INSTANCE_ID_SCOPE (this resolves to the string "FCM", which is FCM’s required scope)
• Drop the final null parameter—it’s no longer needed in the FCM method signature

Key Behavior Note: #

Just like in GCM, the token returned here works for all the Sender IDs in your comma-separated list. You don’t need to call getToken() separately for each Sender ID—this single token is valid for every one of them, which is exactly what you want to keep your code lean.

If you later choose to adopt newer FCM features (like the parameterless FirebaseMessaging.getInstance().getToken() method that returns a token tied to your default Sender ID), you’d need to adjust, but for a straightforward migration, this approach is perfect.

内容的提问来源于stack exchange，提问作者Hey You