@Override public boolean configure(StaplerRequest req, JSONObject json) throws FormException { Jenkins j = Jenkins.get(); try { // for compatibility reasons, this value is stored in Jenkins String num = json.getString("numExecutors"); if (!num.matches("\\d+")) { throw new FormException(Messages.Hudson_Computer_IncorrectNumberOfExecutors(),"numExecutors"); } j.setNumExecutors(json.getInt("numExecutors")); if (req.hasParameter("master.mode")) j.setMode(Mode.valueOf(req.getParameter("master.mode"))); else j.setMode(Mode.NORMAL); j.setLabelString(json.optString("labelString", "")); return true; } catch (IOException e) { throw new FormException(e,"numExecutors"); } } }