JavaBean Objects and "useBean" Action Elements

JSP Tutorials - Herong's Tutorial Examples

∟JavaBean Objects and "useBean" Action Elements

This chapter provides tutorial notes and example codes on using JavaBean in JSP pages. Topics include what is a JavaBean; 'useBean', 'setProperty' and 'getProperty' action elements; using JavaBean objects in scripting elements; refreshing loaded JavaBean classes; Tomcat compilation error when import JavaBean classes declared in unnamed packages.

What Is a JavaBean

"jsp:useBean" Action Elements

"jsp:useBean" Requires Fully Qualified Class Name

Servlet Class Converted from UseBean.jspx

Setting and Getting JavaBean's Properties

Using JavaBean Objects in Scripting Elements

Using Java Objects as JavaBeans

getProperty() Error on Tomcat 7

Refreshing Loaded JavaBean Classes

Importing Unnamed Package Class Error

Using JavaBean without Import Element Error

Creating JavaBean Classes in Named Packages

"NoClassDefFoundError" Exception

Conclusions:

"page import" directive elements can be used to import JavaBean classes into JSP pages.
JavaBean classes must be declared in named packages in order to be imported.
"useBean" action elements can be used to initiate JavaBean objects into JSP pages.
"setProperty" action elements can be used to set new values to JavaBean properties.
"getProperty" action elements can be used to print out values from JavaBean properties.
JavaBean objects can be used in scripting elements.
Refreshing loaded JavaBean classes in Tomcat server can be done by the "Reload" function on the Tomcat admin UI.
JavaBean classes should be declared in named packages, when creating them.
There is no way to import JavaBean classes declared in unnamed packages into JSP pages on Tomcat server.