How to handle a Java Servlet error

[Steve]

I am VERY new to all of this so I ask that you please bear with me.  I am using the Grid and have the editable.mode set to "popup".  I have changed the backend Java Servlet to have an SQL error on purpose to figure out how to do error handling.

In the client javascript for Kendo Grid I have the following which I basically cut and pasted from an example.

schema: {

                errors: "error",

                error : function(e) {
                    alert(e.errors);
                },

I have no idea what I need to do in the servlet in order to send an appropriate error to the client code such that it will be caught.  I tried this but it isn't working:
response.sendError(422, "error: " + exception.getMessage());

[Petur Subev]

Hello Steve,

Is the alert that you put in the error handler displayed, is the event triggered? If it is triggered the only thing left to do is to prevent the rebinding of the Grid by preventing the next dataBinding event:

$("#gridName").data("kendoGrid").one("dataBinding", function(e){
      e.preventDefault();
})

Inside the event argument of the error event handler of the dataSource you should have access to the raw response from the server -> e.xhr. 

http://docs.telerik.com/kendo-ui/api/javascript/data/datasource#events-error

Kind Regards,
Petur Subev
Telerik