Chapter 3 EAServer Components

Java components

EAServer can load and execute a Java class file as a component. The class can be a stand-alone class or part of a JavaBeans component that does not display any graphics or text, that is, a nonvisual JavaBeans component.

Defining the component's interfaces

The definition of a Java component specifies the interfaces that the component implements as well as its other properties.

All component interfaces for EAServer components are defined in CORBA IDL modules that are stored in EAServer's IDL repository. "Defining Component Interfaces" in the EAServer Programmer's Guide describes how to define IDL interfaces.

Java component developers typically use one of the following to define the interface or interfaces that their component implements:

Implement a Java source file and import the methods from it As an alternative to IDL, you can define a Java class or interface, then use Jaguar Manager to import the method definitions from the compiled Java byte code file. EAServer creates a new component definition and an IDL interface that matches the methods defined in the Java file. For more information on this feature, see "Importing interfaces from compiled Java files" in "Defining Component Interfaces" in the EAServer Programmer's Guide.
Use existing interfaces from EAServer's IDL repository In some cases, client and server component developers may have agreed upon an existing interface or several interfaces that a component must implement. In this case, it is up to the component developer to implement the specified interface. EAServer stores HTML documentation for all interfaces in the IDL repository in the html/ir subdirectory of your EAServer installation.
Define one or more new IDL interfaces If you are defining the interface yourself, you can use Jaguar Manager's IDL editor to create a new interface for the component. "Defining modules and interfaces in IDL" in "Defining Component Interfaces" in the EAServer Programmer's Guide describes how.