Listening for Changes to Preference Values in a Preference Node
import java.util.prefs.PreferenceChangeEvent; import java.util.prefs.PreferenceChangeListener; import java.util.prefs.Preferences; public class Main { public static void main(String[] argv) throws Exception { Preferences prefs = Preferences.userNodeForPackage(String.class); prefs.addPreferenceChangeListener(new PreferenceChangeListener() { public void preferenceChange(PreferenceChangeEvent evt) { Preferences node = evt.getNode(); String key = evt.getKey(); String newValue = evt.getNewValue(); } }); prefs.put("key", "a string"); prefs.put("key", "a new string"); prefs.remove("key"); } }