You use jsp:setProperty to give values to properties of beans that have been referenced earlier. You can do this in two contexts. First, you can use jsp:setProperty after, but outside of, a jsp:useBean element, as below:
<jsp:useBean id="myName" ... />
...
<jsp:setProperty name="myName" property="myProperty" ... />
In this case, the jsp:setProperty is executed regardless of whether a new bean was instantiated or an existing bean was found.
A second context in which jsp:setProperty can appear is inside the body of a jsp:useBean element, as below:
<jsp:useBean id="myName" ... >
...
<jsp:setProperty name="myName"
property="someProperty" ... />
</jsp:useBean>
Here, the jsp:setProperty is executed only if a new object was instantiated, not if an existing one was found.
