Developing a Portlet with Multiple Actions

So far we have developed a portlet that has two different views, the default view and an edit view. Adding more views is easy and all you have to do to link to them is to use the jspPage parameter when creating the URL. But we only have one action. How do we add another action, for example for sending an email to the user?

You can have as many actions as you want in a portlet, each of them will need to be implemented as a method that receives two parameters, an ActionRequest and an ActionResponse. The name of the method can be whatever you want since you will be referring to it when creating the URL.

Let's rewrite the example from the previous section to use custom names for the methods of the action to set the greeting and add a second action.

public class MyGreetingPortlet extends MVCPortlet {

    public void setGreeting(
            ActionRequest actionRequest, ActionResponse actionResponse)
        throws IOException, PortletException {

        PortletPreferences prefs = actionRequest.getPreferences();

        String greeting = actionRequest.getParameter("greeting");

        if (greeting != null) {
            try {
                prefs.setValue("greeting", greeting);
                prefs.store();
                        SessionMessages.add(actionRequest, "success");
            }
            catch(Exception e) {
                SessionErrors.add(actionRequest, "error");
            }
        }
    }

    public void sendEmail(
            ActionRequest actionRequest, ActionResponse actionResponse)
        throws IOException, PortletException {

        // Add code here to send an email
    }
}

Note how we no longer need to invoke the processAction method of the super class, because we are not overriding it.

This change of name also requires a simple change in the URL, to specify the name of the method that should be invoked to execute the action. In the edit.jsp edit the actionURL so that it looks like this:

<portlet:actionURL var="editGreetingURL" name="setGreeting">
    <portlet:param name="jspPage" value="/edit.jsp" />
</portlet:actionURL>

That's it, now you know all the basics of portlets and are ready to use your Java knowledge to build portlets that get integrated in Liferay. The next section explains an extension provided by Liferay to the portlet specification to provide pretty URLs to your portlets that you can use if desired.