Question

Within my ajax call if an error is received I have an alert :

    $.ajax({
        url: "myUrl",       
        type: 'POST',
        dataType : "text",
        data : ({
            json : myJson
        }),
        success : function(data) {
                 alert('success');
    },
    error : function() {
                alert ('error');
    } 

From within java is it possible to send back to invoke the error callback in jquery if an exception is thrown. So something like :

    try {
        PrintWriter out = resourceResponse.getWriter();
        out.println("success");
        out.close();
    } catch (Exception e) {
        PrintWriter out = resourceResponse.getWriter();
        out.println("error");
        out.close();
    }

i.e instead of printing “error” on the response, invoke the ‘error’ callback within the jQuery code.

Answer 1

You have to set a http status code of something other than 200 to invoke the error callback in jQuery Ajax. You can set a error staus of 500 (which is for Internal Server Error) like

catch (Exception e) {
    resourceResponse.setProperty(resourceResponse.HTTP_STATUS_CODE, "500"); 
    PrintWriter out = resourceResponse.getWriter();
    out.println("error");
    out.close();
}

in your catch block.