==== 4.1.1 Export File Format ====

Export files are not used directly on a device that implements a Java Card virtual machine. However, the information in an export file is critical to the operation of the virtual machine on a device. An export file can be produced by a Java Card converter when a package is converted. This package's export file can be used later to convert another package that imports classes from the first package. Information in the export file is included in the CAP file of the second package, then is used on the device to link the contents of the second package to items imported from the first package. 

A Java Card technology-based export file ("Java Card export file") contains the public interface information for an entire package of classes. This means that an export file only contains information about the public API of a package, and does not include information used to link classes within a package. 

The name of an export file is the last portion of the package specification followed by the extension `.exp'. For example, the name of the export file of the javacard.framework package must be framework.exp. Operating systems that impose limitations on file name lengths may transform an export file's name according to their own conventions. 

For a complete description of the Java Card export file format, see [[5._The_Export_File_Format| Chapter 5]], "The Export File Format".