如何以编程方式获取android中已连接的usb设备列表？以下代码不起作用

import android.content.Context;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbManager;
import java.util.HashMap;

public class USBDeviceManager {
    private Context context;
    
    public USBDeviceManager(Context context) {
        this.context = context;
    }
    
    public HashMap<String, UsbDevice> getConnectedUSBDevices() {
        HashMap<String, UsbDevice> usbDevices = new HashMap<>();
        
        UsbManager usbManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
        if (usbManager != null) {
            HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
            for (UsbDevice device : deviceList.values()) {
                usbDevices.put(device.getDeviceName(), device);
            }
        }
        
        return usbDevices;
    }
}

<uses-permission android:name="android.permission.USB_PERMISSION" />