Why do you use jsp:useBean?

Question

Hi,
I have one "simple" question :) : When or why do you are using <jsp:useBean>,<jsp:getProperty> and <jsp:setProperty>?
For practice, I am creating a form, sends the data to a servlet and the servlet "packs" the parameter into a Bean and put this Bean into a request- or SessionScope. After that, my resultpage could access the property name of the bean with (for instance) sessionScope.Bean.name.
I wanted to use the 3 tags above first, but after I realised the way I describes above I didn't have to use these three jsp tags. Therefore I wonder when you are using these tags.
Thnx
Alex

Answer 1

hi
The component model for JSP technology is based on JavaBeans component architecture. JavaBeans components are nothing but Java objects which follow a well-defined design/naming pattern: the bean encapsulates its properties by declaring them private and provides public accessor (getter/setter) methods for reading and modifying their values.
Before you can access a bean within a JSP page, it is necessary to identify the bean and obtain a reference to it. The <jsp:useBean> tag tries to obtain a reference to an existing instance using the specified id and scope, as the bean may have been previously created and placed into the session or application scope from within a different JSP page. The bean is newly instantiated using the Java class name specified through the class attribute only if a reference was not obtained from the specified scope. Consider the tag:
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