The Java™ implementation of the toolkit is based on an abstract main class called DSETagSupport. This class extends TagSupport in the standard JSP libraries to work correctly with typed data and their element states in runtime. For example, if an input field must be read only, the browser renders it as read only even though it is not declare read only in the JSP. DSETagSupport uses JSPContextServices to get the information about the model required to set up the JSP PageContext.
The four abstract classes (DSETagSupport and the link, list, and table subgroups) have the set methods needed to initialize the JSP objects from the attributes of each tag declared in the JSP. All of the custom JSP tags have a doStartTag() method to implement the corresponding HTML tag, and the tag classes that need to close the HTML tag have a doEndTag() method. The classes that need to implement an action have do methods.