Java Beans Interview Questions and Answers
Ques 16. Is the InfoBus client side only?
Yes. InfoBus is typically used to communicate among Beans at the client, and it can also be useful for sharing information among components at a single server site. The initial version of InfoBus is not distributed, and is therefore not intended for transmission of data between clients and servers.
A variety of Java communication services, including JDBC, CORBA, and RMI can be used by InfoBus components for access to distributed data. For example, the ESuite Data Access component is a Bean that connects any JDBC compliant data source to the InfoBus. Once the data is on the bus, it can easily be imported by any InfoBus Data Consumer, such as a spreadsheet, chartingcomponent, word processor or data analysis tool.
Ques 17. Difference between java Beans and Enterprise Java Beans?
► JavaBeans may be visible or nonvisible at runtime.For
example, the visual GUI component may be a button,list
box,graphic or a chart.
An EJB is a nonvisual ,remote object.
► JavaBeans are intended to be local to a single process
and are primarly intended to run on the client side.Although
one can develop server-side JavaBeans,it is far easier to
develop them using the EJB specification instead.
EJB's are remotely executable components or business
objects that can be deployed only on the server.
► JavaBeans is a component technology to create generic
Java components that can be composed together into applets
and applications.
Even though EJB is a component technology,it neither
builds upon nor extends the original JavaBean specification.
► JavaBeans have an external interface called the properties
interface, which allows a builder tool to interpret the
functionality of the bean.
EJBs have a dployement descriptor that describes its
functionality to an external builder tool or IDE
► JavaBeans may have BeanInfo classes,property editors or
customizers
Ques 18. What is the relation between the InfoBus and RMI?
The InfoBus architecture addresses Beans talking to one in a single JVM not across multiple JVMs; while RMI (Remote Method Invocation) is intended for communication across JVMs (different Java Virtual Machines across the network). As for IIOP, one can envision a JavaBeans component that uses RMI to talk to something on another JVM and then publishes the data on the InfoBus.
Additionally, RMI could be used to allow components in different security classes to communicate within the same JVM.
Ques 19. Why is the JavaBeans Bridge for ActiveX only available on Windows/X86?
Sun's JavaBeans Bridge for ActiveX is platform specific due to the platform specific nature of ActiveX. Currently, ActiveX is essentially a Window/X86 platform specific component architecture.
If Microsoft delivers ActiveX libraries and ActiveX applications on other platforms, Sun will evaluate customer demand and respond accordingly.
Ques 20. Who is developing the JavaBeans Migration Assistant to ActiveX?
IBM and Taligent, its object oriented technology subsidiary, with support from JavaSoft, are developing a set of conversion conventions, a porting guide and tool that will allow developers to easily convert their Windows ActiveX components into JavaBeans.
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