Java 如何设置自定义声音？

我在哪里放音，你能帮我吗

Uri uri = Uri.parse("android.resource://" + context.getPackageName() + "/" + R.raw.musound);
        notificationBuilder.setSound(uri);

我会尽力的

Uri uri = Uri.parse("android.resource://" + context.getPackageName() + "/" + R.raw.musound);
        notificationBuilder.setSound(uri);

但当我发送通知时，我的应用程序将崩溃

Uri uri = Uri.parse("android.resource://" + context.getPackageName() + "/" + R.raw.musound);
        notificationBuilder.setSound(uri);

这里是logcat报告

Uri uri = Uri.parse("android.resource://" + context.getPackageName() + "/" + R.raw.musound);
        notificationBuilder.setSound(uri);

进程：com.example.ciyashop，PID:13336 java.lang.NullPointerException：尝试对空对象引用调用虚拟方法“java.lang.String android.content.Context.getPackageName（）” 在com.example.ciyashop.fcm.MyFirebaseMessagingService.sendNotification（MyFirebaseMessagingService.java:96）上 在com.example.ciyashop.fcm.MyFirebaseMessagingService.onMessageReceived（MyFirebaseMessagingService.java:47）上

Uri uri = Uri.parse("android.resource://" + context.getPackageName() + "/" + R.raw.musound);
        notificationBuilder.setSound(uri);

---

context

为

null

context

为

null

。