Learn Java for Web Development

CHAPTER 2: Building Web Applications Using Servlets and JSP 93

Step 5: Accessing the Model from the View

In the previous step, the controller forwards to the view home.jsp using the RequestDispatcher.

Listing 2-30 illustrates a fragment of home.jsp, which includes leftColumn.jsp. The leftColumn.jsp
file uses the model Category to display categories on the left menu of the home page.

Listing 2-30. Including leftColumn.jsp in home.jsp

1.
2.

   Line 6: The <jsp:include> tag is used to include leftColumn.jsp. This is done

because the left-side bar of the application (the menu) is common to all screens

in the application, but instead of writing the left-side bar in all screens, we write

it in one JSP page and include it wherever required as a means to reusability.

(In the next few chapters on web frameworks, we will see more advanced

techniques for reusing JSPs.)

Listing 2-31 illustrates the code fragment related to categories in leftColumn.jsp where the Category
is accessed.

Listing 2-31. Accessing the Category Model in leftColumn.jsp

1.

   Line 4: In this line, the category list is obtained from the ServletContext.

We had saved the category list in the ServletContext obtained from the

database in step 2.

   Line 6 to 10: The category details are displayed in the markup, such as the

category description that you see on the home page.