The above picture shows the components of DBPrism framework.
Wrappers - handle the incoming request from a Cocoon framework or a Servlet engine
and adapt them to the DBPrism request. They also return the generated XML or HTML
page to clients.
Engine - processes the request calling to the specific Stored Procedure, analyzing
the request and choosing the target database according to the information given.
This Engine doesn't deal with database specific problems such as types or argument
match in the Stored Procedure. The Engine takes the connection from the Resource Manager,
which implements a configurable pool of database connections and transaction support
by a URL demarcation. The information attached to the connection is stored in a
DAD dictionary. DAD stands for Database Access Descriptor and is a piece of
configurable information stored in the DBPrism configuration file. This file
contains, for example, user name and password to connect to the database, type
of the database to be connected to, and all other necessary connection information.
Adapters - make the actual call to the specific Stored Procedure in a target database,
each adapter deals with the database specific problems such as
"How are Stored Procedures stored in the database dictionary?"
and "How do I get the generated page from the database side?".
Each adapter includes three classes - a Factory to handle the creation process,
a Database Connection which implements the real Stored Procedure call
(JDBC callable statement), and Stored Procedure objects that encapsulate the name
and arguments of a Stored Procedure in the database.
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