For a time picker you can use a JSpinner and set a JSpinner.DateEditor that only shows the time value.
JSpinner timeSpinner = new JSpinner( new SpinnerDateModel() );
JSpinner.DateEditor timeEditor = new JSpinner.DateEditor(timeSpinner, "HH:mm:ss");
timeSpinner.setEditor(timeEditor);
timeSpinner.setValue(new Date()); // will only show the current time