android 检测USB是U盘还是外设

UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);  
  
HashMap<String, UsbDevice> deviceList = manager.getDeviceList();  

Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();  

StringBuilder sb = new StringBuilder();  
while (deviceIterator.hasNext()){  
    UsbDevice usbDevice = deviceIterator.next();  
    sb.append("DeviceName="+usbDevice.getDeviceName()+"\n");  
    sb.append("DeviceId="+usbDevice.getDeviceId()+"\n");  
    sb.append("VendorId="+usbDevice.getVendorId()+"\n");  
    sb.append("ProductId="+usbDevice.getProductId()+"\n");  
    sb.append("DeviceClass="+usbDevice.getDeviceClass()+"\n");  
    int deviceClass = usbDevice.getDeviceClass();  
    if (deviceClass == 0) {  
        UsbInterface anInterface = usbDevice.getInterface(0);  
        int interfaceClass = anInterface.getInterfaceClass();  

        sb.append("device Class 为0-------------\n");  
        sb.append("Interface.describeContents()="+anInterface.describeContents()+"\n");  
        sb.append("Interface.getEndpointCount()="+anInterface.getEndpointCount()+"\n");  
        sb.append("Interface.getId()="+anInterface.getId()+"\n");  
        //http://blog.csdn.net/u013686019/article/details/50409421  
        //http://www.usb.org/developers/defined_class/#BaseClassFFh  
        //通过下面的InterfaceClass 来判断到底是哪一种的，例如7就是打印机，8就是usb的U盘  
        sb.append("Interface.getInterfaceClass()="+anInterface.getInterfaceClass()+"\n");  
        if (anInterface.getInterfaceClass() == UsbConstants.USB_CLASS_PRINTER) {  
            sb.append("此设备是打印机\n");  
        } else if(anInterface.getInterfaceClass() == UsbConstants.USB_CLASS_MASS_STORAGE){  
            sb.append("此设备是U盘\n");  
        } else if(anInterface.getInterfaceClass() == UsbConstants.USB_CLASS_HUB){  
            sb.append("此设备是HUB\n");  
        }  
        sb.append("anInterface.getInterfaceProtocol()="+anInterface.getInterfaceProtocol()+"\n");  
        sb.append("anInterface.getInterfaceSubclass()="+anInterface.getInterfaceSubclass()+"\n");  
        sb.append("device Class 为0------end-------\n");  
    }  

    sb.append("DeviceProtocol="+usbDevice.getDeviceProtocol()+"\n");  
    sb.append("DeviceSubclass="+usbDevice.getDeviceSubclass()+"\n");  
    sb.append("+++++++++++++++++++++++++++\n");  
    sb.append("                           \n");  
}  

textView.setText(sb);  
}  

根据不同anInterface.getInterfaceClass()就可以看出来是什么，我已经试出来3是外设，7是打印机，8是U盘，其他的值，你可以根据与自己的需要，插上看看打印是什么。

可以查看 UsbConstants.USB_CLASS_MASS_STORAGE