sendRedirect in custom action class - liferay

Question

I am overriding one of the actions of the calendar portlet . I want to do some functionality then redirect to another JSP after that. I tried using the sendRedirect function as follows:
1.
String redirect = ParamUtil.getString(actionRequest , "redirect");
actionResponse.sendRedirect(redirect);
2.
actionResponse.sendRedirect ("/calendar/view") ;
3.
ThemeDisplay themeDisplay = (ThemeDisplay) actionRequest.getAttribute(WebKeys.THEME_DISPLAY);
PortletURL url = PortletURLFactoryUtil.create(PortalUtil.getHttpServletRequest(actionRequest), "8", themeDisplay.getPlid(),
PortletRequest.RENDER_PHASE);
url.setParameter("struts_action", "/calendar/view");
actionResponse.sendRedirect (url.toString()) ;
However, none of the methods cause the jsp to redirect to another one.
I am doing so in the processAction function and I am extending the BaseStrutsPortletAction.
Any suggestions how to solve it?
This is my overridden file :
public class TestAction extends BaseStrutsPortletAction {
public void processAction(StrutsPortletAction originalStrutsPortletAction, PortletConfig portletConfig,
ActionRequest actionRequest, ActionResponse actionResponse) throws Exception {
String cmdConstants = ParamUtil.getString(actionRequest, Constants.CMD);
if (cmdConstants.equals(Constants.APPROVE)) {
//some function
actionResponse.setRenderParameter("test", "test");
originalStrutsPortletAction.processAction(portletConfig, actionRequest, actionResponse);
}
}
public String render(StrutsPortletAction originalStrutsPortletAction, PortletConfig portletConfig, RenderRequest renderRequest,
RenderResponse renderResponse) throws Exception {
String cmdConstants = ParamUtil.getString(renderRequest, Constants.CMD);
if (cmdConstants.equals(Constants.APPROVE)) {
if (renderRequest.getParameter("test").equals("test")) {
return "/portlet/calendar/view.jsp";
}
}
return originalStrutsPortletAction.render(null, portletConfig, renderRequest, renderResponse);
}
}