IT. Expert System.

public class UsbDeviceConnection
extends Object

• Constructor Summary

  Constructors

  Constructor and Description
  UsbDeviceConnection(UsbDevice device) UsbDevice should only be instantiated by UsbService implementation

• Method Summary

  Methods

  Modifier and Type	Method and Description
  int	bulkTransfer(UsbEndpoint endpoint, byte[] buffer, int length, int timeout) Performs a bulk transaction on the given endpoint.
  boolean	claimInterface(UsbInterface intf, boolean force) Claims exclusive access to a UsbInterface.
  void	close() Releases all system resources related to the device.
  int	controlTransfer(int requestType, int request, int value, int index, byte[] buffer, int length, int timeout) Performs a control transaction on endpoint zero for this device.
  int	getFileDescriptor() Returns the native file descriptor for the device, or -1 if the device is not opened.
  byte[]	getRawDescriptors() Returns the raw USB descriptors for the device.
  String	getSerial() Returns the serial number for the device.
  boolean	releaseInterface(UsbInterface intf) Releases exclusive access to a UsbInterface.
  UsbRequest	requestWait() Waits for the result of a UsbRequest.queue(java.nio.ByteBuffer, int) operation Note that this may return requests queued on multiple UsbEndpoints.

  • Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• Constructor Detail

  • UsbDeviceConnection

    public UsbDeviceConnection(UsbDevice device)

    UsbDevice should only be instantiated by UsbService implementation

• Method Detail

  • close

    public void close()

    Releases all system resources related to the device. Once the object is closed it cannot be used again. The client must call UsbManager.openDevice(android.hardware.usb.UsbDevice) again to retrieve a new instance to reestablish communication with the device.

  • getFileDescriptor

    public int getFileDescriptor()

    Returns the native file descriptor for the device, or -1 if the device is not opened. This is intended for passing to native code to access the device.

    Returns:

    the native file descriptor

  • getRawDescriptors

    public byte[] getRawDescriptors()

    Returns the raw USB descriptors for the device. This can be used to access descriptors not supported directly via the higher level APIs.

    Returns:

    raw USB descriptors

  • claimInterface

    public boolean claimInterface(UsbInterface intf,
                         boolean force)

    Claims exclusive access to a UsbInterface. This must be done before sending or receiving data on any UsbEndpoints belonging to the interface.

    Parameters:

    intf - the interface to claim

    force - true to disconnect kernel driver if necessary

    Returns:

    true if the interface was successfully claimed

  • releaseInterface

    public boolean releaseInterface(UsbInterface intf)

    Releases exclusive access to a UsbInterface.

    Returns:

    true if the interface was successfully released

  • controlTransfer

    public int controlTransfer(int requestType,
                      int request,
                      int value,
                      int index,
                      byte[] buffer,
                      int length,
                      int timeout)

    Performs a control transaction on endpoint zero for this device. The direction of the transfer is determined by the request type. If requestType & UsbConstants.USB_ENDPOINT_DIR_MASK is UsbConstants.USB_DIR_OUT, then the transfer is a write, and if it is UsbConstants.USB_DIR_IN, then the transfer is a read.

    Parameters:

    requestType - request type for this transaction

    request - request ID for this transaction

    value - value field for this transaction

    index - index field for this transaction

    buffer - buffer for data portion of transaction, or null if no data needs to be sent or received

    length - the length of the data to send or receive

    timeout - in milliseconds

    Returns:

    length of data transferred (or zero) for success, or negative value for failure

  • bulkTransfer

    public int bulkTransfer(UsbEndpoint endpoint,
                   byte[] buffer,
                   int length,
                   int timeout)

    Performs a bulk transaction on the given endpoint. The direction of the transfer is determined by the direction of the endpoint

    Parameters:

    endpoint - the endpoint for this transaction

    buffer - buffer for data to send or receive,

    length - the length of the data to send or receive

    timeout - in milliseconds

    Returns:

    length of data transferred (or zero) for success, or negative value for failure

  • requestWait

    public UsbRequest requestWait()

    Waits for the result of a UsbRequest.queue(java.nio.ByteBuffer, int) operation Note that this may return requests queued on multiple UsbEndpoints. When multiple endpoints are in use, UsbRequest.getEndpoint() and UsbRequest.getClientData() can be useful in determining how to process the result of this function.

    Returns:

    a completed USB request, or null if an error occurred

  • getSerial

    public String getSerial()

    Returns the serial number for the device. This will return null if the device has not been opened.

    Returns:

    the device serial number