# Parse push fields (/en/realtime-media/im/build/notifications-and-event-handling/offline-push/parse-push-fields/android)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

After receiving a push notification, you need to parse the data.

    Rewrite the `FirebaseMessagingService.onMessageReceived` method to get the custom extension field in the `RemoteMessage` object. The sample code is as follows:

    ```java
    public class FCMMSGService extends FirebaseMessagingService {
        @Override
        public void onMessageReceived(RemoteMessage remoteMessage) {
            super.onMessageReceived(remoteMessage);
            if (remoteMessage.getData().size() > 0) {
                String f = remoteMessage.getData().get("f");
                String t = remoteMessage.getData().get("t");
                String m = remoteMessage.getData().get("m");
                String g = remoteMessage.getData().get("g");
                Object e = remoteMessage.getData().get("e");
            }
        }

        @Override
        public  void  handleIntent ( @NonNull  Intent  intent ) {
            super.handleIntent(intent);
            Bundle bundle = intent . getExtras();
            if (bundle != null) {
                Map map = new HashMap<>();
                for (String key : bundle.keySet()) {
                    if (!TextUtils.isEmpty(key)) {
                    Object content = bundle.get(key);
                    map.put(key, content);
                    }
                }
                Log.i(TAG, "handleIntent: " + map);
            }
       }
    }
    ```

    | Parameter | Description                                              |
    | --------- | -------------------------------------------------------- |
    | `f`       | The user ID of the push notification sender.             |
    | `t`       | The user ID of the push notification recipient.          |
    | `m`       | The message ID: A unique identifier of the message.      |
    | `g`       | The group ID: This field exists only for group messages. |
    | `e`       | The user-defined extension field.                        |

    `e` is a completely user-defined extension. The data source is `em_push_ext.custom` of the message extension. The data structure is as follows:

    ```json
    {
        "em_push_ext": {
            "custom": {
                "key1": "value1",
                "key2": "value2"
            }
        }
    }
    ```

    The data structure of the extension in the `RemoteMessage` object is as follows:

    ```java
    {
        "t":"receiver",
        "f":"fromUsername",
        "m":"msg_id",
        "g":"group_id",
        "e":{}
    }
    ```