Netscape Internet Service Broker for Java: Programmer's Guide, Version 1.0
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Chapter 7
The Interface Repository
Overview
The interface repository (IR) maintains information about ORB objects and their type. Type information is stored on objects such as modules, interfaces, operations, attributes and exceptions. An IDL interface is provided that enables client applications to query the IR to obtain language binding information or to discover newly added interfaces. The ORB accesses the IR to check the type of values in a client request or to verify an interface inheritance graph. Every object in the IR can be accessed as anorg.omg.CORBA.IRObject, which is the most generic interface. IRObject provides methods for narrowing, cloning, and duplicating an IRObject reference. It also allows you to identify the type of an IRObject.
IR Structure
The IR organizes the objects it contains into a hierarchy that corresponds to the way objects are defined in an IDL specification. Some objects in the IR contain other objects, just as an IDL module definition might contain several interface definitions. Consider how the following IDL file would translate to a hierarchy of objects in the IR.
The bank/bank.idl file.
// Bank.idl
Figure 7.1 IR object hierarchy for the Bank.idl specification.
module Bank {
interface Account {
float balance();
};
interface AccountManager {
Account open(in string name);
};
};
Identifying IR Objects
The following table lists objects provided to identify and classify IR objects.
IRObject Types
The following table summarizes the objects that can be contained in the IR.
Using the IR
To use the IR, do the following:
Setting VBROKER_ADM
TheVBROKER_ADM environment variable specifies the default location for the ORB log file. It enables the Interface Repository to locate the default repository files. If VBROKER_ADM is not set, the files will reside in a \log directory on the current drive by default.
Starting the IR
Use theirep command to start the IR. Specify an interface repository server and, optionally, a database containing detailed descriptions of IDL interfaces. For example:
prompt> irep my_ir ir_dbThis command is described in the Netscape Internet Service Broker for Java Reference Guide.
Populating the IR
Theidl2ir command can be used to populate an IR instance with objects defined in an IDL file. For example, the following command populates an IR named my_repository with objects defined in the file Bank.idl.
prompt> idl2ir -ir my_repository java_examples/bank/Bank.idlThis command is described in the Netscape Internet Service Broker for Java Reference Guide. You can also write your own applications that bind to an IR and add objects.
Accessing the IR
The IR offers an ORB interface that provides your client applications with a variety of methods for obtaining information about objects in the IR. Your client application can bind to the Repository and then invoke the methods shown in the Repository class (described in the Netscape Internet Service Broker for Java Reference Guide).[Contents] [Previous] [Next]
Last Updated: 02/04/98 13:47:00
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