Jump the hurdles of Struts development

Tips for solving common difficulties in Struts

By Michael Coen and Amarnath Nanduri, JavaWorld.com, 04/18/03

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<?xml version="1.0" encoding="ISO-8859-1" ?>
<!-- Struts Config XML - Sample Struts App -->
<!-- ===================================== -->
<!-- AutoGenerated from : c:\dev\javaworld\app\sample.vsd -->
<!-- AutoGenerated on   : 02-18-2003 23:05:47 -->
<!-- AutoGenerated by   : Struts GUI v2.11   (c)2002 Alien-Factory -->
<!--                    : See 'http://www.alien-factory.co.uk' for details -->
<!-- GET YOUR STICKY FINGERS OFF! i.e. Do not edit. -->
<!DOCTYPE struts-config PUBLIC
      "-//Apache Software Foundation//DTD Struts Configuration 1.0//EN"
      "http://jakarta.apache.org/struts/dtds/struts-config_1_0.dtd">
<struts-config>
  <!-- ====================== Form Bean Definitions =================== -->
  <form-beans>
  </form-beans>
  <!-- ================= Global Forward Definitions =================== -->
  <global-forwards>
  </global-forwards>
  <!-- ======================= Action Definitions ===================== -->
  <action-mappings>
    <action  path="/Login"
             type="com.agilquest.onboard.presentation.actions.LoginAction">
      <description>Authenticates and authorizes a user.</description>
    </action>
  </action-mappings>
  
</struts-config>

To make your user interface flow diagrams more complete, we recommend an additional step when using StrutsGUI. Within your StrutsGUI Visio document, you can easily link each JSP (JavaServer Pages) page to its actual screen shot in the application. Not only does creating this artifact aid in documenting the application, but more importantly, it becomes an excellent tool for training new developers about the user interface design.

Another tool that helps manage Struts applications is the Struts Console created by James Holmes. In essence, it provides facilities that enable you to get to the same endpoint as StrutsGUI, but differs in approach and strengths. Both tools perform well, and either will enhance a Struts-based enterprise application's maintenance.

Now, where did I put that form?

ActionForm session management can be tricky. What should the ActionForm's life be? Should it be in request scope or session scope? One solution to this problem puts the ActionForm in session for the life of the functionality it is supposed to represent.

In such a case, how do you maintain these ActionForm objects generically? Who assumes the responsibility of cleaning up these ActionForm objects once they are no longer needed? A typical scenario is when a user traverses from one functionality to another through a menu. In that case, the old ActionForm objects should be removed from the session and new ActionForm objects created. A centralized Action class, called MenuAction, which deals only with the menu traversal, should be present. This Action class deletes the redundant ActionForm objects from the session. It then forwards the user to the new page where new ActionForm objects are created.

Given this, how do we show the different menu items to the user based on her role or permissions? This menu should also be internationalized, and it can change based on the user permissions; that is, if the permissions change, the menu must change accordingly. One such approach persists the user's permissions. When she logs in, a MenuFactory creates menus from these permissions. For additional safety, the MenuAction class can then authorize the user before permitting her to proceed to the selected functionality.