code: @Deprecated
      public FormValidation doFieldCheck(@QueryParameter(fixEmpty=true) String value,
                                         @QueryParameter(fixEmpty=true) String type,
                                         @QueryParameter(fixEmpty=true) String errorText,
                                         @QueryParameter(fixEmpty=true) String warningText) {
          if (value == null) {
              if (errorText != null)
                  return FormValidation.error(errorText);
              if (warningText != null)
                  return FormValidation.warning(warningText);
              return FormValidation.error("No error or warning text was set for fieldCheck().");
          }
  
          if (type != null) {
              try {
                  if (type.equalsIgnoreCase("number")) {
                      NumberFormat.getInstance().parse(value);
                  } else if (type.equalsIgnoreCase("number-positive")) {
                      if (NumberFormat.getInstance().parse(value).floatValue() <= 0)
                          return FormValidation.error(Messages.Hudson_NotAPositiveNumber());
                  } else if (type.equalsIgnoreCase("number-negative")) {
                      if (NumberFormat.getInstance().parse(value).floatValue() >= 0)
                          return FormValidation.error(Messages.Hudson_NotANegativeNumber());
                  }
              } catch (ParseException e) {
                  return FormValidation.error(Messages.Hudson_NotANumber());
              }
          }
  
          return FormValidation.ok();
      }
docs: Checks if the value for a field is set; if not an error or warning text is displayed.
  If the parameter "value" is not set then the parameter "errorText" is displayed
  as an error text. If the parameter "errorText" is not set, then the parameter "warningText"
  is displayed as a warning text.
  <p>
  If the text is set and the parameter "type" is set, it will validate that the value is of the
  correct type. Supported types are "number, "number-positive" and "number-negative".
  
  @deprecated as of 1.324
  Either use client-side validation (e.g. class="required number")
  or define your own check method, instead of relying on this generic one.