Java in a Nutshell, 5th Edition

JavaBeans Conventions

JavaBeans is a framework for defining reusable modular software components. The JavaBeans specification includes the following definition of a bean: “a reusable software component that can be manipulated visually in a builder tool.” As you can see, this is a rather loose definition; beans can take a variety of forms. The most common use of beans is for graphical user interface components, such as components of the java.awt and javax.swing packages, which are documented in Java Foundation Classes in a Nutshell and Java Swing, both from O’Reilly. Although all beans can be manipulated visually, this does not mean every bean has its own visual representation. For example, the javax.sql.RowSet class (documented in O’Reilly’s Java Enterprise in a Nutshell) is a JavaBeans component that represents the data resulting from a database query. There are no limits on the simplicity or complexity of a JavaBeans component. The simplest beans are typically basic graphical interface components, such as a java.awt.Button object. But even complex systems, such as an embeddable spreadsheet application, can function as individual beans.

The JavaBeans component model consists of the java.beans, the java.beans.beancontext packages, and a number of important naming and API conventions to which conforming beans and bean-manipulation tools must adhere. These conventions are not part of the JavaBeans API itself but are in many ways more important to bean developers than the API itself. ...