public class MyPreferenceStore extends PreferenceStore {
	
	private Preferences preferences;
	
	public MyPreferenceStore() {
		super();
		this.preferences = InstanceScope.INSTANCE.getNode(FrameworkUtil.getBundle(getClass()).getSymbolicName());
		setDefault(MY_PREFERENCE_1, "Default_1");
		setDefault(MY_PREFERENCE_2, "Default_2");
	}
	
	@Override
	public void load() throws IOException {
		
		StringBuffer propEntries = new StringBuffer();
		propEntries.append(createPropertyEntry(MY_PREFERENCE_1, "Default_1"));
		propEntries.append(createPropertyEntry(MY_PREFERENCE_2, "Default_2"));

		InputStream stream = new ByteArrayInputStream(propEntries.toString().getBytes(StandardCharsets.UTF_8));
		load(stream);
		stream.close();
	}
	
	private String createPropertyEntry(String key, String defaultValue){
		String value = preferences.get(key, defaultValue);
		return key + "=" + value + System.getProperty("line.separator");
	}
	
	@Override
	public void save() throws IOException {
		
		savePreference(MY_PREFERENCE_1);
		savePreference(MY_PREFERENCE_2);
		
		// To set dirty = false;
		load();
		
		try {
			preferences.flush();
		} catch (BackingStoreException e) {
			e.printStackTrace();
		}
		
	}
	
	private void savePreference(String key){
		preferences.put(key, getString(key));
	}
}