Bridging Beans and Active X

While JavaBeans might be the greatest thing since sliced bread, the reality is that the dominant desktop environment and some of the major applications designed for it are built to use ActiveX components. Thus, JavaBean developers have been quick to provide a solution: the JavaBeans bridge for ActiveX.

This solution enables any JavaBean to be used as a first-class ActiveX component -- that is, it lets you mix JavaBeans with ActiveX components. The bridge run-time looks to the s ystem like an ActiveX control, while at the same time giving the Bean a Java environment.

The package contains a utility that allows the capabilities of a JavaBean to be expressed in terms of OLE-type-library and Windows-registry information. After the definition of the Bean is added to the Windows system, programs can create instances of it, and tools such as Visual Basic can interrogate its properties. The bridge run-time code then provides the mappings among the JavaBean, OLE events, and method calls so that everything is transparent to both the user and the JavaBean. This is significant: Creators of JavaBeans don't need to know whether their Beans are in an ActiveX container. They don't have to write any extra or specialized code to enable their Beans to be used as ActiveX components.

JavaBeans also provides tools for taking existing ActiveX components and turning them into JavaBeans in the form of the JavaBeans Migration Assistant for ActiveX. The Migration Assistant analyzes an ActiveX control and provides the skeleton implementation of a JavaBean that exhibits the equivalent public interface. It isn't able to convert the implementation code to Java, but it provides a quick start.

You can download the JavaBeans bridge for ActiveX from the JavaSoft Beans Web pages ( http://java.sun.com/Beans ).