DouKaku?

package org.doukaku.ja.preference;

import java.util.prefs.Preferences;
import java.util.prefs.BackingStoreException;

public class HelloPreference {
    private static final String MESSAGE_KEY = "message";
    private static final String DEFAULT_MESSAGE = "Hello, Preference.";

    private String message;
    private Preferences pref;

    public HelloPreference() {
        loadPreference();
    }

    public void loadPreference() {
        setPreference(Preferences.userNodeForPackage(this.getClass()));
        setMessage(pref.get(MESSAGE_KEY, DEFAULT_MESSAGE));
    }

    public void setMessage(String message) { this.message = message; }
    public String getMessage() { return this.message; }
    public void setPreference(Preferences pref) { this.pref = pref; }
    public Preferences getPreference() { return this.pref; }

    public void showMessage() {
        System.out.println(getMessage());
    }
    public void storePreference() throws BackingStoreException {
        Preferences pref = getPreference();
        pref.put(MESSAGE_KEY, getMessage());
        pref.flush();
    }

    public static void main(String[] args) {
        try {
            HelloPreference    hello = new HelloPreference();
            if (args.length > 0) {
                hello.setMessage(args[0]);
            }
            hello.showMessage();
            hello.storePreference();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}