Alguém entende esse método?

protected Map validate()
    {
        Map result = null;
        String strPage = getLastPage();
        MaintainServiceRequisitionController controller = new MaintainServiceRequisitionController();
        if (strPage.equalsIgnoreCase("reqMaintain.jsp") || strPage.equalsIgnoreCase("reqMaintainPJ.jsp"))
        {
            if (strPage.indexOf("PJ") > 0)
                putInSession("requisitionType", "J");
            else
                putInSession("requisitionType", "F");
            String lastUser = (String)getSessionData("lastUser");
            String lastPerson = (String)getSessionData("lastPerson");
            boolean isRefresh = "reqMaintain.jsp".equals(getActualPage()) || "reqMaintainPJ.jsp".equals(getActualPage());
            result = controller.validateHeader(getAttributeMap(), lastUser, lastPerson, isRefresh);
            ServiceType servType = getServiceType(controller);
            if(servType != null){
                putInSession("serviceType", servType);
                getAttributeMap().put("serviceType", servType);
            }
        }
        if (strPage.equalsIgnoreCase("reqMaintain2.jsp") || strPage.equalsIgnoreCase("reqMaintainPJ2.jsp"))
        {
            ServiceType servType = getServiceType(controller);
            putInSession("serviceType", servType);
            getAttributeMap().put("serviceType", servType);
            boolean isRefresh = "reqMaintain2.jsp".equals(getActualPage());
            result = controller.validateInformation(getAttributeMap(), servType, isRefresh);
        }
        return result;
    }