Description
The package layout is designed to help enforce the logical isolation of PIMs, DIMs and Channels and also maps reasonably to the distribution of PAM as two zip files. The interfaces package identifies the key interfaces for the architecture. One role these interfaces play is to isolate the executive from the rest of the system so that different executives may be developed over time.The executive package (not to be confused with the Exec class mentioned elsewhere) contains executive services that startup, save, connect, and schedule PIMs, DIMs, and Channels. In the future, the executive package may be merged with the store package.
DIMs, Datacaster Interface Modules are part of the putter package. PIMs, Provider Interface Modules have the task of getting information, so they are part of the getter package. Channels may receive and forward information or they may store and augment the result of PIMs -- hence they are part of the aggregator package.
The product.view package contains the software to describe the internal representation of channel information. The product.visit package contains renderers that visit Products and create files in the proper format for delivery over various media and protocols. The util package serves as a collection point for general software classes that may be used by more than one of the other packages.
The monitor package contains classes that have the job of interacting with the executive to: 1) monitor what is happening; 2) change the configuration of the system (including building new information channels). This includes local GUI as well as a number of Servlets that provide remote access as part of a Java-based Web server.
The pdif package contains classes that support the serialization and deserialization of an information space in a human-legible, machine parseable format called the Platform Independent Data Interchange Format (PDIF). These classes will probably undergo further change to more closely integrate them with Java serialization.
Revised: 11 January 1999