marshalling/unmarshalling

In few words, "marshalling" refers to the process of converting the data or the objects inbto a byte-stream, and "unmarshalling" is the reverse process of converting the byte-stream beack to their original data or object. The conversion is achieved through "serialization".

The purpose of the "marshalling/unmarshalling" process is to transfer data between the RMI system.

Source: http://www.jguru.com/faq/view.jsp?EID=560072

What we will define in Struts-config.xml file.

The main control file in the Struts framework is the struts-config.xml XML file, where action mappings are specified. This file's structure is described by the struts-config DTD file, which is defined at http://jakarta.apache.org/struts/. A copy of the DTD can be found on the /docs/dtds subdirectory of the framework's installation root directory. The top-level element is struts-config. Basically, it consists of the following elements:

data-sources—A set of data-source elements, describing parameters needed to instantiate JDBC 2.0 Standard Extension DataSource objects

form-beans—A set of form-bean elements that describe the form beans that this application uses

global-forwards—A set of forward elements describing general available forward URIs

action-mappings—A set of action elements describing a request-to-action mapping

Types of Struts Taglib

Following are the six Struts libraries:

• Bean Tags
• HTML Tags
• Logic Tags
• Nested Tags
• Template Tags
• Tiles Tags

Struts: Parameter and Name rules

Here is some lowdown you can refer to:
(1)
it compares request.getParameter("drpState") to "AZ"

(2)
it compares licensesData.toString() to "AZ"

(3)
it compares licensesData.getDrpState().toString() to "AZ"

In your case, , it is same as (2), it compares licensesData.toString() to "AZ".
Pick one syntax you think right for you and you are good to go :)

courtesy: actonwang (guru) link: http://www.experts-exchange.com/Programming/Languages/Java/J2EE/JSP/Q_21622460.html