empty - Evaluate the nested body content of this tag if the requested variable is either null or an empty string.

This tag evaluates its nested body content only if the specified value is either absent (i.e. null), an empty string (i.e. a java.lang.String with a length of zero), or an empty java.util.Collection or java.util.Map (tested by the .isEmpty() method on the respective interface).

JSTL: The equivalent JSTL tag is <c:if> using the empty operator. For example,
<c:if test="${empty sessionScope.myBean.myProperty}"> do something </c:if>

Since: Struts 1.1

Attribute Name Description
name

The variable to be compared is the JSP bean specified by this attribute, if property is not specified, or the value of the specified property of this bean, if property is specified.

[RT Expr]
property

The variable to be compared is the property (of the bean specified by the name attribute) specified by this attribute. The property reference can be simple, nested, and/or indexed.

[RT Expr]
scope

The bean scope within which to search for the bean named by the name property, or "any scope" if not specified.

[RT Expr]