The dsp:droplet
tag lets you invoke a servlet bean from a JSP page. It encapsulates programming logic in a server-side JavaBean and makes that logic accessible to the JSP page that calls it. Tag output is held by its parameters, which can be referenced by nested tags.
Attributes
Servletbeaninstance:name(Required)
The name
attribute is set to the Nucleus path and servlet bean you want to invoke.
MapVariableholdingServletBeanParameters:var
The var
attribute provides a name to a Map variable that holds a servlet bean’s parameters and parameter values. The var
attribute enables EL access to the servlet’s parameters. When you use var
, you can set the scope
attribute to determine the context—such as page
or request
—the variable exists in.
The name given to the var
attribute is usually a shorthand version of the servlet bean name, such as ForEach
might use fe
.
TagVariable:id
The id
attribute names a scripting variable that scriptlets and expressions can access at runtime.
VariableScope:scope
The scope
attribute determines where the Map variable identified by the var
attribute is stored and what resources can access it. Options include: page
and request
. Omitting this attribute causes the default, page
, to be used.
Examples
<dsp:droplet var="fe" name="/atg/dynamo/droplet/ForEach">
<dsp:param bean="/samples/Student_01.subjects" name="array"/>
<dsp:oparam name="outputStart">
<p>The student is registered for these courses:
</dsp:oparam>
<dsp:oparam name="output">
<li><c:out value="${fe.element}"/>
</dsp:oparam>
</dsp:droplet>
In this example, the dsp:droplet
tag calls the ForEach
servlet bean and creates a Map variable called fe
that saves each parameter and parameter value used on this page. The ForEach
servlet bean iterates through each item in the Student_01.subjects
array and, beneath the message text The student is registered for these courses
,the c:out
JSTL tag uses EL to displays each item.