A single line input field that lets the user select a number or an object value from an ordered sequence. Spinners typically provide a pair of tiny arrow buttons for stepping through the elements of the sequence. The keyboard up/down arrow keys also cycle through the elements. The user may also be allowed to type a (legal) value directly into the spinner. Although combo boxes provide similar functionality, spinners are sometimes preferred because they don't require a drop down list that can obscure important data.

A JSpinner's sequence value is defined by its SpinnerModel. The model can be specified as a constructor argument and changed with the model property. SpinnerModel classes for some common types are provided: SpinnerListModel, SpinnerNumberModel, and SpinnerDateModel.

A JSpinner has a single child component that's responsible for displaying and potentially changing the current element or value of the model, which is called the editor. The editor is created by the JSpinner's constructor and can be changed with the editor property. The JSpinner's editor stays in sync with the model by listening for ChangeEvents. If the user has changed the value displayed by the editor it is possible for the model's value to differ from that of the editor. To make sure the model has the same value as the editor use the commitEdit method, eg:

  try {
      spinner.commitEdit();
  }
  catch (ParseException pe) {
      // Edited value is invalid, spinner.getValue() will return
      // the last valid value, you could revert the spinner to show that:
      JComponent editor = spinner.getEditor();
      if (editor instanceof DefaultEditor) {
          ((DefaultEditor)editor).getTextField().setValue(spinner.getValue());
      }
      // reset the value to some known value:
      spinner.setValue(fallbackValue);
      // or treat the last valid value as the current, in which
      // case you don't need to do anything.
  }
  return spinner.getValue();

For information and examples of using spinner see How to Use Spinners, a section in The Java Tutorial.