Borrowed From:
http://www.baigzeeshan.com/2011/05/how-to-execute-javascript-in-java-in.html
import javax.faces.context.FacesContext;
import org.apache.myfaces.trinidad.render.ExtendedRenderKitService;
import org.apache.myfaces.trinidad.util.Service;FacesContext fctx = FacesContext.getCurrentInstance();
ExtendedRenderKitService erks =
Service.getRenderKitService(fctx, ExtendedRenderKitService.class);
String myJavaScriptCode = “alert( “+”Hello World”+”);”;
erks.addScript(fctx, myJavaScriptCode );