ProcessAction annotation

The JSR 286 interface introduces concept of ProcessAction annotation that you can use for marking a method that can be used for handling particular action. I built a simple portlet to demonstrate how you can use @ProcessAction annotation, you can download the sample portlet from here

This is how my ProcessActionAnnotationPortlet.java looks like

package com.webspherenotes.portlet.jsr286;

import java.io.IOException;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.GenericPortlet;
import javax.portlet.PortletException;
import javax.portlet.ProcessAction;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

public class ProcessActionAnnotationPortlet extends GenericPortlet{

  protected void doView(RenderRequest request, RenderResponse response)
      throws PortletException, IOException {
    System.out.println("Entering ProcessActionAnnotationPortlet.doView()");
    response.setContentType("text/html");
    
    getPortletContext().getRequestDispatcher("/index.jsp").include(request, response);
    System.out.println("Exiting ProcessActionAnnotationPortlet.doView()");
  }

  @ProcessAction(name="action1")
  public void handleAction1(ActionRequest request, ActionResponse response)throws PortletException,IOException{
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction1()");
    System.out.println("Value of ACTION_NAME " + request.getParameter(ActionRequest.ACTION_NAME));
    response.setRenderParameter("action", "action1");
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction1()");
  }

  @ProcessAction(name="action2")
  public void handleAction2(ActionRequest request, ActionResponse response)throws PortletException,IOException{
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction2()");
    System.out.println("Value of ACTION_NAME " + request.getParameter(ActionRequest.ACTION_NAME));
    response.setRenderParameter("action", "action2");
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction2()");
  }

  @ProcessAction(name="action3")
  public void handleAction3(ActionRequest request, ActionResponse response)throws PortletException,IOException{
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction3()");
    System.out.println("Value of ACTION_NAME " + request.getParameter(ActionRequest.ACTION_NAME));
    response.setRenderParameter("action", "action3");
    System.out.println("Entering ProcessActionAnnotationPortlet.handleAction3()");
  }

}

As you can see i have three methods that are marked with @ProcessAction annotation, the handleAction1, is marked with @ProcessAction(name="action1"), which means that whenever there is processAction call with value of javax.portlet.action parameter equal to action1, it will call handleAction1 method.

The Annotations are implemented using GenericPortlet For a received action the processAction method in the GenericPortlet class tries to dispatch to methods annotated with the tag @ProcessAction(name=<action name>), where the action name must be set on the ActionURL as value of the parameter javax.portlet.action (or via the constant ActionRequest.ACTION_NAME), and following signature:

          void <methodname> (ActionRequest, ActionResponse) throws
                                PortletException, java.io.IOException;

A portlet that wants to leverage this action dispatching needs to set the parameter ActionRequest.ACTION_NAME on the action URL.


This is how my JSP looks like

<%@page language="java" contentType="text/html; %>
<%@taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet"%> 
<portlet:defineObjects />
Current Action - <%=renderRequest.getParameter("action") %> <br/>
<portlet:actionURL var="action1Url">
 <portlet:param name="javax.portlet.action" value="action1" />
</portlet:actionURL>
<a href='<%=action1Url %>' >Action1 URl</a><br/>

<portlet:actionURL var="action2Url">
 <portlet:param name="javax.portlet.action" value="action2" />
</portlet:actionURL>
<a href='<%=action2Url %>' >Action2 URl</a><br/>

<portlet:actionURL var="action3Url">
 <portlet:param name="javax.portlet.action" value="action3" />
</portlet:actionURL>
<a href='<%=action3Url %>' >Action3 URl</a><br/>