java开发usb实例1Preface1.1IntroductionJSR80istheJavaSpecificationRequestconcernedwithcommunicationwithUniversalSerialBus(USB)devices.ThisdocumentdescribestheAPIassociatedwiththisJSR.2USBBusTopologyThestructureoftheUSBbusistopological.TherootoftheUSBphysicalbusisaphysicalHostCon-troller,whichiscontainedinacomputersystem.HostContro