A task of the reconfiguration that has not yet been discussed is the loading of the implementation classes. The loader acts as intermediate piece between the adaptors and the repository. The implementation classes are loaded from the repository by the loader and handed over to the adaptors where they are linked into the core. The concept of the class loader is a standard concept of the Java technology and supports the implementation of user defined class loaders as needed for the reconfiguration.
The contribution of reconfiguration to adaptation is the design pattern, the concept of adaptor classes and the loader. The design pattern pretends to the application programmer, to define the functionality of the implementation classes in a functionality interface, which is implemented by all implementation classes. E.g. to program an adaptable class that retrieves the information about the total and the free disk space, i.e. Harddisk in a non-adaptable version, the programmer defines for an adaptable version the functionality interface IHarddisk, and the implementation classes Harddisk_AIX_PPC, Harddisk_WINNT_X86 and Harddisk_LINUX_X86. In the non-adaptable parts of the mobile code an adaptor class is used instead of Harddisk. The adaptor class IHarddisk_Adaptor is being generated out of the functionality interface IHarddisk by a generator, similar to the CORBA IDL compiler.
Another aspect of adaptation which has not yet been explained is the resolution of the implementation class name from the functionality interface and the environment. This is done by context awareness as explained in the following section.