ViewHelpers are JavaBeans following the Command pattern.
They provide a no-args constructor, a perform() method that initializes its properties, and getter methods to retrieve them.
ViewHelpers are used by JSP developers to perform presentation logic, retrieve data or call business services.
By providing a clear interface to the JSP developers, they simplify the development process.
By hiding the complexities of database retrieval or business service calls and putting them inside testable Java classes, they increase the quality of the software.
By offering an additional level of indirection, they eliminate the coupling between the business-tier and the Views represented by the JSP.
Take a look at the
examples and taglib documentation
to learn more.