how to call an activity from the java, java script. | Pega Interview Questions

<Script>s
Function A ()
{
var urlPath = "./PRServlet" ;
var url = urlPath + "?pyActivity=GHC-HPlan-CS-Work.ABC&CSR=" + CSR;
window.open(urlPath,"_self");
}
</script>
 Or  you can use osafeURL to call an activity
Using  java :
      sHashStringMap activityKeys = new HashStringMap();
    activityKeys.putString("pxObjClass", "Rule-Obj-Activity");
    activityKeys.putString("pyClassName", workclass);
    activityKeys.putString("pyActivityName", "HistoryAndAttachments" );
    tools.doActivity(activityKeys , workpage, tools.getParameterPage() );