How to detect if Android has full USB support or not?
android, usb, usb-otg
Solution
The official way to determine if the device has USB host capability is to use the associated system feature.
Ideally, add a `<uses-feature>` element to your manifest, indicating that you are interested in the `android.hardware.usb.host` feature. If you do not absolutely need that feature, add `android:required="false"` as an attribute.
If you went with `android:required="false"`, and you want to determine whether the device is a USB host at runtime, use `PackageManager`, `hasSystemFeature()`, and `FEATURE_USB_HOST`. `FEATURE_USB_HOST` is defined as the same string as you would be using in `<uses-feature>` (`android.hardware.usb.host`).
Problem
My application uses `UsbManager` to communicate with USB cameras. Some devices don't have USB support. These will return `null` for `(UsbManager)context.getSystemService( Context.USB_SERVICE )`, or they will throw a `NoSuchMethodError` exception when enumerating devices. I can detect both and display a message properly. Unfortunately, some Androids that don't detect USB devices cause neither of these problems. They just return an empty list of USB devices. How can I properly detect that this system doesn't support USB OTG?