Creating a Portlet Action Class

When developing a local portlet, you can implement one or more action classes for the portlet. If you use an action class, then the following requirements must be met:

• You must specify the class in your portlet deployment descriptor file (portlet.xml).

• The class must implement com.sas.portal.portlet.PortletActionInterface.

• The class can extend DefaultPortletAction or HTMLPortletAction in com.sas.portal.portlet.

The DefaultPortletAction and HTMLPortletAction contain two simple methods for setting and getting an instance of com.sas.portal.portlet.PortletActionInfoInterface, as shown in this example:

public void setInfo(PortletActionInfoInterface pai) {
        _actionInfo = pai;
    }
    public PortletActionInfoInterface getInfo() {
        return _actionInfo;
    }

The primary method, called service(), runs before the portlet is displayed and every time the portlet is redisplayed. For example, it runs after a user interacts with the portlet or with a different portlet on the same page.

The service() method is provided with the HttpServletRequest, HttpServletResponse, and PortletContext objects. From the PortletContext object, you can obtain the HttpSession object, which provides access to the most important servlet objects.

Your service() method must return a string representing a valid URL for the portlet. Typically, the URL is the name of the portlet's JSP page. If your initializer places the display-page property of the portlet.xml into the PortletContext, then you can obtain the URL as in this example:

String url = (String) context.getAttribute("display-page");

If user interaction with your portlet requires a different URL string, then you can return that URL instead.

The service() method can handle any kind of exception subclass that is thrown by code within your action. If your portlet action needs to throw an exception, then you can use the portlet error handler. For more information, see Error Handling.