Java Bean

What is the criteria for a java program to qualify as a java bean ?

JavaBeans are not programs, but software components that you write to build programs bottom up.
From Java Bean FAQ at Sun...
...typical unifying features that distinguish a Bean are:

Introspection: enables a builder tool to analyze how a Bean works

Customization: enables a developer to use an app builder tool to customize the appearance and behavior of a Bean

Events: enables Beans to communicate and connect together

Properties: enable developers to customize and program with Beans

Persistence: enables developers to customize Beans in an app builder, and then retrieve those Beans, with customized features intact, for future

Moving this discussion to Java in General( intermediate) forum..

Thank You...1 Doubt , i just read somewehere that Beans can be manually manipulated by text tools through programatic interfaces. Could u give an example ?

In short, the answer is yes, that's possible, but without any sense of what kind of tool, it's difficult to offer a concrete example.
Cindy mentioned the Beanbox, which Sun offered for a long time as a proof-of-concept for manipulating JavaBeans in a graphic environment. And that's basically the idea behind JavaBeans in the first place: to make it possible for front-end application designers to build interfaces and change behavior through keyboard and mouse instead of writing program code.
Virtually any IDE incorporate this behavior as a matter of course: Forte for Java, VisualAge, JBuilder, Symantec Cafe, and I am sure a ton of others. But JavaBeans is very much a fundamental need to drive IDEs and CASE tools for Java; the concept is nothing groundbreaking at all.
[ January 02, 2003: Message edited by: Michael Ernest ]

A tool that can manipulate JavaBeans is called a BeanBox. Basically it is like a "GUI painter". Because all of the components that can be manipulated by it follow standard conventions, the tool "knows" how to work the components, even though it does not know what the component it actually might run into.
How to write a JavaBean.