Package opencard.opt.iso.fs

Interface CardFileInfo

  • All Known Implementing Classes:
    CardFile, IsoFileControlInformation
    public interface CardFileInfo
    Provides information about the structure of a file. File information is obtained from the smartcard by selecting a file. The file may be a dedicated file (DF, also referred to as directory) or an elementary file (EF). The smartcard typically responds with the selected file's header.
    Unlike the select command itself, the file header is not subject to standards, so it cannot be encapsulated in a predefined class. This interface defines some methods that should be implementable regardless of the particular card and it's select response. Most of these methods provide information about the structure of an elementary file.
    The comments to the methods required by this interface assume knowledge of the file types defined by ISO 7816. Some information about these file types can be found in the comments to FileAccessCardService. The term the file, which is frequently used in the comments, refers to the file on the smartcard for which an instance of this interface provides information.
    Author:
    Roland Weber (rolweber@de.ibm.com)
    See Also:
    FileAccessCardService

    • Method Detail

      • getFileID

        short getFileID()
        Returns the identifier of the file. It is most likely that this method is of no particular use, but since the file identifier is the most basic information about a file at all, it is included here anyway.
        Returns:
        the identifier of the file

      • isDirectory

        boolean isDirectory()
        Tests whether the file is a DF.
        Returns:
        true if the file is a DF, false otherwise

      • isTransparent

        boolean isTransparent()
        Tests whether the file is a transparent file. The value returned is valid only if the file is not a DF, that is if isDirectory returns false.
        Returns:
        true if the file is a transparent file
        See Also:
        isDirectory()

      • isCyclic

        boolean isCyclic()
        Tests whether the file is a cyclic file. The value returned is valid only if the file is not a DF and not a transparent file, that is if isDirectory as well as isTransparent return false.
        Returns:
        true if the file is a cyclic file
        See Also:
        isDirectory(), isTransparent()

      • isVariable

        boolean isVariable()
        Tests whether the file is a variable record file. The value returned is valid only if the file is not a DF and not a transparent file, that is if isDirectory as well as isTransparent return false.
        Returns:
        true if the file is a structured file with variable record size
        See Also:
        isDirectory(), isTransparent()

      • getLength

        int getLength()
        Returns the length of the file. If the file is a transparent file, that is if isDirectory returns false and isTransparent returns true, this method returns the number of bytes in the file.
        If the file is a structured file with fixed record length, either cyclic or non-cyclic, this method returns also returns the number of bytes in the file, that is the size of a record multiplied by the number of bytes in a record.
        If the file is a DF, a structured file with variable record length, or some card specific file type, the value returned by this method is implementation dependent.
        Returns:
        the number of bytes in the file
        See Also:
        isDirectory(), isTransparent()

      • getRecordSize

        int getRecordSize()
        Returns the record size of the file. The value returned is valid only if the file is a structured file with fixed record size, that is if isDirectory, isTransparent and isVariable return false.
        Returns:
        the size of a record of the file
        See Also:
        isDirectory(), isTransparent(), isVariable()

      • getHeader

        byte[] getHeader()
        Returns the file header. This method actually returns the smartcard's response (or expected response) to a selection of the file. For an EF, this is the file header which may have been expanded by some application data, if the card OS allows to do so. For a DF, this is the file header, also optionally expanded, or some other data that has been defined as the select response for the DF. The EMV standard requires the select response for a DF to be defineable by applications.
        This method is not invoked by the OpenCard Framework, and it is not yet clear whether it will be useful for applications. However, removing a method from this interface will be easier than adding it later, so it is currently required. File services that do not want to support this method may simply return null.
        Returns:
        the smartcard's response to a selection of the file, or null if not supported