Source code for print pdf via usb and Bluetooth printers

I want android programmer(java) to programme simple app(with source code) that print a invoice (pdf) via usb and Bluetooth printers as shown on the image below
Take a look on printing side of this app ,I want something similar (JUST THE PRINTING SIDE )
https://play.google.com/store/apps/details?id=com.loyverse.sale

I need this done sonner