类调用自己的静态方法必须把该方法设置为public

否则调用不了

        ParaChecker.isOK(bindingResult);

public class ParaChecker {

    static BaseResult paraCheck(BindingResult bindingResult) {
        if (bindingResult.hasErrors()) {
            Map<String, Object> map = new HashMap<>();
            List<FieldError> fieldErrors = bindingResult.getFieldErrors();
            for (FieldError fieldError :
                    fieldErrors) {
                map.put(fieldError.getField(), fieldError.getDefaultMessage());
            }
            return ResultUtil.error(303, "参数异常").add("errorFields", map);
        }
        return null;
    }

    public static BaseResult isOK(BindingResult bindingResult) {
        BaseResult baseResult = paraCheck(bindingResult);
        if (baseResult != null) {
            return baseResult;
        } else {
            return null;
        }
    }
}