private ServiceReference createReference(List<ServiceReference> references, String symbolicName) {
ServiceReference ref = Mockito.mock(ServiceReference.class);
Mockito.when(ref.getProperty("org.springframework.context.service.name"))
.thenReturn(symbolicName);
references.add(ref);
return ref;
}
@Override
@SuppressWarnings("unchecked")
public <T> T createProxy(
BundleContext bundleContext, ServiceReference reference, ClassLoader classLoader) {
Bundle exportingBundle = reference.getBundle();
if (exportingBundle == null) {
throw new IllegalArgumentException(
String.format("Service [%s] has been unregistered", reference));
}
InvocationHandler handler = new OsgiInvocationHandler(bundleContext, reference);
String[] classNames = (String[]) reference.getProperty(Constants.OBJECTCLASS);
List<Class<?>> classes = new ArrayList<Class<?>>(classNames.length);
for (String className : classNames) {
try {
Class<?> clazz = classLoader.loadClass(className);
if (clazz.isInterface()) {
classes.add(clazz);
}
} catch (ClassNotFoundException e) {
throw new IllegalArgumentException(
String.format(
"Unable to find class [%s] with classloader [%s]", className, classLoader));
}
}
classes.add(OsgiProxy.class);
classes.add(ServiceReference.class);
return (T)
Proxy.newProxyInstance(classLoader, classes.toArray(new Class<?>[classes.size()]), handler);
}
@Override
public int compare(ServiceReference<T> serviceReference1, ServiceReference<T> serviceReference2) {
if (serviceReference1 == null) {
if (serviceReference2 == null) {
return 0;
} else {
return 1;
}
} else if (serviceReference2 == null) {
return -1;
}
Object propertyValue1 = serviceReference1.getProperty(_propertyKey);
Object propertyValue2 = serviceReference2.getProperty(_propertyKey);
if (propertyValue1 == null) {
if (propertyValue2 == null) {
return 0;
} else {
return 1;
}
} else if (propertyValue2 == null) {
return -1;
}
if (!(propertyValue2 instanceof Comparable)) {
return serviceReference2.compareTo(serviceReference1);
}
Comparable<Object> propertyValueComparable2 = (Comparable<Object>) propertyValue2;
return propertyValueComparable2.compareTo(propertyValue1);
}
@Test
public void testOwnerCannotSeeServiceClass() throws Exception {
final Bundle bundleA = installBundle(getBundleArchiveA());
final Bundle bundleB = installBundle(getBundleArchiveB());
try {
bundleA.start();
bundleB.start();
BundleContext contextA = bundleA.getBundleContext();
BundleContext contextB = bundleB.getBundleContext();
final CountDownLatch latch = new CountDownLatch(1);
ServiceListener listener =
new ServiceListener() {
public void serviceChanged(ServiceEvent event) {
latch.countDown();
}
};
contextB.addServiceListener(listener);
Object service = bundleB.loadClass(B.class.getName()).newInstance();
ServiceRegistration reg = contextA.registerService(B.class.getName(), service, null);
ServiceReference ref = reg.getReference();
assertTrue(ref.isAssignableTo(bundleA, B.class.getName()));
assertTrue(ref.isAssignableTo(bundleB, B.class.getName()));
if (latch.await(5, TimeUnit.SECONDS) == false) throw new TimeoutException();
} finally {
bundleA.uninstall();
bundleB.uninstall();
}
}
private void createNotifier(String deviceId) {
ServiceReference[] serviceListeners = null;
ServiceReference serviceReference = null;
Filter filter = null;
String eventListenerFilter =
"(" + Constants.OBJECTCLASS + "=" + UPnPEventListener.class.getName() + ")";
properties = new Properties();
properties.put(UPnPDevice.ID, deviceId);
properties.put(UPnPService.ID, serviceId);
try {
serviceListeners = context.getServiceReferences(UPnPEventListener.class.getName(), null);
if (serviceListeners != null && serviceListeners.length > 0) {
for (int i = 0; i < serviceListeners.length; i++) {
serviceReference = serviceListeners[i];
filter = (Filter) serviceReference.getProperty(UPnPEventListener.UPNP_FILTER);
if (filter == null) {
eventListeners.add(serviceReference);
} else if (filter.match(properties)) {
addNewListener(serviceReference);
}
}
}
} catch (Exception e) {
}
try {
String filterString = eventListenerFilter;
context.addServiceListener(this, filterString);
} catch (Exception e) {
}
}
@Test
public void testRegBundleIsRefBundle() throws Exception {
Bundle bundle = installBundle(getBundleArchiveA());
try {
bundle.start();
final CountDownLatch latch = new CountDownLatch(1);
ServiceListener listener =
new ServiceListener() {
public void serviceChanged(ServiceEvent event) {
latch.countDown();
}
};
BundleContext context = bundle.getBundleContext();
context.addServiceListener(listener);
Object service = bundle.loadClass(A.class.getName()).newInstance();
ServiceRegistration reg = context.registerService(A.class.getName(), service, null);
ServiceReference ref = reg.getReference();
assertTrue(ref.isAssignableTo(bundle, A.class.getName()));
if (latch.await(5, TimeUnit.SECONDS) == false) throw new TimeoutException();
} finally {
bundle.uninstall();
}
}
private static ServiceReferenceDTO getServiceReferenceDTO(ServiceReference<?> ref) {
if (ref == null) {
return null;
}
Bundle b = ref.getBundle();
if (b == null) {
// service has been unregistered
return null;
}
ServiceReferenceDTO dto = new ServiceReferenceDTO();
dto.bundle = b.getBundleId();
String[] keys = ref.getPropertyKeys();
Map<String, Object> properties = newMap(keys.length);
for (String k : keys) {
Object v = ref.getProperty(k);
if (Constants.SERVICE_ID.equals(k)) {
dto.id = ((Long) v).longValue();
}
properties.put(k, mapValue(v));
}
dto.properties = properties;
Bundle[] using = ref.getUsingBundles();
final int length = (using == null) ? 0 : using.length;
long[] usingBundles = new long[length];
for (int i = 0; i < length; i++) {
usingBundles[i] = using[i].getBundleId();
}
dto.usingBundles = usingBundles;
return dto;
}
@SuppressWarnings({"rawtypes", "unchecked", "unused"})
private void logServiceProperties(final Class<?> klaz, final Object instance) throws Exception {
final BundleContext context = bundleContext();
final ServiceReference[] referenceArray = context.getAllServiceReferences(klaz.getName(), null);
for (final ServiceReference reference : referenceArray) {
final Object service = context.getService(reference);
if (service == instance) {
log.info("instance=" + instance);
final String[] propKeyArray = reference.getPropertyKeys();
for (final String propKey : propKeyArray) {
final Object propValue = reference.getProperty(propKey);
log.info(propKey + "=" + propValue);
}
// final String[] nameArray = (String[]) reference
// .getProperty("objectClass");
// for (final String name : nameArray) {
// log.info("name=" + name);
// }
}
}
}
@Override
public void start(BundleContext context) throws Exception {
LOG.info("Starting Bundle");
// Get our name.
String myName = context.getBundle().getSymbolicName();
// Find reference.
ServiceReference<HelloService> ref = context.getServiceReference(HelloService.class);
if (ref != null) {
try {
// Print service properties.
String props = getServiceProperties(ref);
LOG.info(
"Calling HelloService#sayHello('{}') Published by {}. Props:\n{}",
myName,
ref.getBundle().getSymbolicName(),
props);
// Get the service
HelloService service = context.getService(ref);
if (service != null) {
service.sayHello(myName);
}
} finally {
// Release reference
context.ungetService(ref);
}
}
}
/**
* An apform instance to represent a legacy component discovered in the OSGi registry
*
* @param ipojoInstance
*/
public ApformOSGiInstance(Specification specification, ServiceReference<?> reference) {
super(
new InstanceDeclaration(
VersionedReference.any(generateImplementationName(specification, reference)),
generateInstanceName(specification, reference)));
this.specification = specification;
for (PropertyDefinition property : specification.getDeclaration().getPropertyDefinitions()) {
Object value = reference.getProperty(property.getName());
if (value != null) this.declaration.getProperties().put(property.getName(), value.toString());
}
this.reference = reference;
this.bundle = reference.getBundle();
this.bundleContext =
AccessController.doPrivileged(
new PrivilegedAction<BundleContext>() {
public BundleContext run() {
return bundle.getBundleContext();
}
});
this.service = null;
}
private Collection<CommandName> listCommands() {
Set<CommandName> commands = new HashSet<>();
ServiceReference<?>[] refs;
try {
refs = context.getAllServiceReferences(null, "(osgi.command.scope=*)");
} catch (InvalidSyntaxException e) {
// should never happen
throw new RuntimeException(e);
}
for (ServiceReference<?> ref : refs) {
String scope = (String) ref.getProperty("osgi.command.scope");
Object funcsObj = ref.getProperty("osgi.command.function");
String[] funcs;
if (funcsObj instanceof String[]) funcs = (String[]) funcsObj;
else if (funcsObj instanceof String) funcs = new String[] {(String) funcsObj};
else funcs = new String[0];
for (String func : funcs) {
CommandName command = new CommandName(scope, func);
commands.add(command);
}
}
return commands;
}
/** @param serviceReference */
private void addBatchProcessor(ServiceReference serviceReference) {
SolrSearchBatchResultProcessor processor =
(SolrSearchBatchResultProcessor)
osgiComponentContext.locateService(SEARCH_BATCH_RESULT_PROCESSOR, serviceReference);
Long serviceId = (Long) serviceReference.getProperty(Constants.SERVICE_ID);
batchProcessorsById.put(serviceId, processor);
String[] processorNames =
getSetting(serviceReference.getProperty(REG_BATCH_PROCESSOR_NAMES), new String[0]);
if (processorNames != null) {
for (String processorName : processorNames) {
batchProcessors.put(processorName, processor);
}
}
// bit of a kludge until I can figure out why felix doesn't wire up the default
// processor even though it finds a matching service.
boolean defaultBatchProcessor =
getSetting(
serviceReference.getProperty(
SolrSearchBatchResultProcessor.DEFAULT_BATCH_PROCESSOR_PROP),
false);
if (defaultBatchProcessor) {
defaultSearchBatchProcessor = processor;
}
}
/**
* Should only be called while holding a lock from {@link #lock}
*
* @return
*/
private Snapshot getSnapshot(boolean openingPrices) {
lock.readLock().lock();
try {
Availability availability = getCurrentAvailability();
/* Nothing we can check */
if (availability == Availability.NONE) {
return new Snapshot(availability, null, Collections.<String, Double>emptyMap());
}
/* Pick a random Jedis to call */
Map<ServiceReference<Endpoint>, JedisPool> toUse =
new HashMap<ServiceReference<Endpoint>, JedisPool>(writableMap);
toUse.putAll(readableMap);
ServiceReference<Endpoint> ref = getARandomJedis(toUse);
/* Get the prices */
Map<String, Double> prices = getPrices(toUse.get(ref), openingPrices);
while (prices == null && !toUse.isEmpty()) {
// This Jedis didn't work!
toUse.remove(ref);
ref = getARandomJedis(toUse);
prices = getPrices(toUse.get(ref), openingPrices);
}
/* Return the data */
return (prices == null)
? new Snapshot(Availability.NONE, null, Collections.<String, Double>emptyMap())
: new Snapshot(availability, (String) ref.getProperty(Endpoint.URI), prices);
} finally {
lock.readLock().unlock();
}
}
/** @param serviceReference */
private void removeBatchProcessor(ServiceReference serviceReference) {
Long serviceId = (Long) serviceReference.getProperty(Constants.SERVICE_ID);
SolrSearchResultProcessor processor = processorsById.remove(serviceId);
if (processor != null) {
List<String> toRemove = new ArrayList<String>();
for (Entry<String, SolrSearchResultProcessor> e : processors.entrySet()) {
if (processor.equals(e.getValue())) {
toRemove.add(e.getKey());
}
}
for (String r : toRemove) {
processors.remove(r);
}
// bit of a kludge until I can figure out why felix doesn't wire up the default
// processor even though it finds a matching service.
boolean defaultBatchProcessor =
getSetting(
serviceReference.getProperty(
SolrSearchBatchResultProcessor.DEFAULT_BATCH_PROCESSOR_PROP),
false);
if (defaultBatchProcessor) {
defaultSearchBatchProcessor = null;
}
}
}
public void serviceChanged(ServiceEvent serviceEvent) {
int serviceEventType = serviceEvent.getType();
switch (serviceEventType) {
case ServiceEvent.REGISTERED:
{
ServiceReference serviceReference = serviceEvent.getServiceReference();
Filter filter = (Filter) serviceReference.getProperty(UPnPEventListener.UPNP_FILTER);
if (filter == null) {
addNewListener(serviceReference);
} else if (filter.match(properties)) {
addNewListener(serviceReference);
}
}
;
break;
case ServiceEvent.MODIFIED:
{
}
;
break;
case ServiceEvent.UNREGISTERING:
{
removeListener(serviceEvent.getServiceReference());
}
;
break;
}
}
public int compareTo(Object reference) {
ServiceReference other = (ServiceReference) reference;
Long id = (Long) getProperty(Constants.SERVICE_ID);
Long otherId = (Long) other.getProperty(Constants.SERVICE_ID);
if (id.equals(otherId)) {
return 0; // same service
}
Object rankObj = getProperty(Constants.SERVICE_RANKING);
Object otherRankObj = other.getProperty(Constants.SERVICE_RANKING);
// If no rank, then spec says it defaults to zero.
rankObj = (rankObj == null) ? new Integer(0) : rankObj;
otherRankObj = (otherRankObj == null) ? new Integer(0) : otherRankObj;
// If rank is not Integer, then spec says it defaults to zero.
Integer rank = (rankObj instanceof Integer) ? (Integer) rankObj : new Integer(0);
Integer otherRank =
(otherRankObj instanceof Integer) ? (Integer) otherRankObj : new Integer(0);
// Sort by rank in ascending order.
if (rank.compareTo(otherRank) < 0) {
return -1; // lower rank
} else if (rank.compareTo(otherRank) > 0) {
return 1; // higher rank
}
// If ranks are equal, then sort by service id in descending order.
return (id.compareTo(otherId) < 0) ? 1 : -1;
}
/**
* * Call all plugins contained in a list and * optionally allow modifications. * *
*
* @param targetServiceReference Reference to the target ManagedService(Factory). *
* @param servicePid The service PID corresponding to the current configuration
* @param dictionary The configuration dictionary to process. *
* @param plugins list of references to ConfigurationPlugins. *
* @param allowModification Should modifications to the configuration dictionary be allowed. * *
* @return The modified configuration dictionary.
*/
private ConfigurationDictionary callPlugins(
ServiceReference targetServiceReference,
String servicePid,
ConfigurationDictionary dictionary,
List plugins,
boolean allowModification) {
ConfigurationDictionary currentDictionary = dictionary;
Iterator it = plugins.iterator();
while (it.hasNext()) {
ServiceReference pluginReference = (ServiceReference) it.next();
// Only call the plugin if no cm.target is specified or if it
// matches the pid of the target service
String cmTarget = (String) pluginReference.getProperty(ConfigurationPlugin.CM_TARGET);
if (cmTarget == null || cmTarget.equals(servicePid)) {
ConfigurationPlugin plugin = (ConfigurationPlugin) context.getService(pluginReference);
if (plugin == null) {
continue;
}
ConfigurationDictionary dictionaryCopy = new ConfigurationDictionary(dictionary);
try {
plugin.modifyConfiguration(targetServiceReference, dictionaryCopy);
if (allowModification) {
currentDictionary = dictionaryCopy;
}
} catch (Exception exception) {
LOG.error("[CM] Exception thrown by plugin: " + exception.getMessage());
}
}
}
return currentDictionary;
}
/** Handles service change events. */
public void serviceChanged(ServiceEvent event) {
ServiceReference serviceRef = event.getServiceReference();
// if the event is caused by a bundle being stopped, we don't want to
// know
if (serviceRef.getBundle().getState() == Bundle.STOPPING) {
return;
}
Object service = MUCActivator.bundleContext.getService(serviceRef);
// we don't care if the source service is not a protocol provider
if (!(service instanceof ProtocolProviderService)) {
return;
}
switch (event.getType()) {
case ServiceEvent.REGISTERED:
addQueryToProviderPresenceListeners((ProtocolProviderService) service);
break;
case ServiceEvent.UNREGISTERING:
removeQueryFromProviderPresenceListeners((ProtocolProviderService) service);
break;
}
}
public String getText(Object obj) {
if (obj instanceof ServiceReference) {
ServiceReference r = (ServiceReference) obj;
JanusModule m = (JanusModule) getBundleContext().getService(r);
return m.getName() + " (Provider = " + r.getBundle().getSymbolicName() + ")";
}
return obj.toString();
}
/** Generate the uniques name of the implementation associated with this instance in Apam */
private static ImplementationReference<?> generateImplementationName(
Specification specification, ServiceReference<?> reference) {
String bundle = reference.getBundle().getSymbolicName();
if (bundle == null) bundle = (String) reference.getBundle().getHeaders().get("Bundle-Name");
return new ApformOSGiImplementation.Reference(
specification.getName() + "[provider.bundle=" + bundle + "]");
}
private void removePluginReference(Object serviceId, List pluginsList) {
for (int i = 0; i < pluginsList.size(); ++i) {
ServiceReference serviceReference = (ServiceReference) pluginsList.get(i);
Long currentId = (Long) serviceReference.getProperty(Constants.SERVICE_ID);
if (currentId.equals(serviceId)) {
pluginsList.remove(i);
return;
}
}
}
private void printAppConfigurationDetails(PrintWriter pw) {
Map<String, Realm> configs = getConfigurationDetails();
if (configs.isEmpty()) {
pw.println("No JAAS LoginModule registered");
return;
}
pw.println("<p class=\"statline ui-state-highlight\">${Registered LoginModules}</p>");
pw.println("<table class=\"nicetable\">");
pw.println("<thead><tr>");
pw.println("<th class=\"header\">${Realm}</th>");
pw.println("<th class=\"header\">${Rank}</th>");
pw.println("<th class=\"header\">${Control Flag}</th>");
pw.println("<th class=\"header\">${Type}</th>");
pw.println("<th class=\"header\">${Classname}</th>");
pw.println("</tr></thead>");
for (Realm r : configs.values()) {
String realmName = r.getRealmName();
pw.printf(
"<tr class=\"ui-state-default\"><td>%s</td><td colspan=\"4\"></td></tr>", realmName);
String rowClass = "odd";
for (AppConfigurationHolder ah : r.getConfigs()) {
LoginModuleProvider lp = ah.getProvider();
String type = getType(lp);
pw.printf("<tr class=\"%s ui-state-default\"><td></td><td>%d</td>", rowClass, lp.ranking());
pw.printf("<td>%s</td>", ControlFlag.toString(lp.getControlFlag()));
pw.printf("<td>%s</td>", type);
pw.printf("<td>");
pw.print(lp.getClassName());
if (lp instanceof OsgiLoginModuleProvider) {
ServiceReference sr = ((OsgiLoginModuleProvider) lp).getServiceReference();
Object id = sr.getProperty(Constants.SERVICE_ID);
pw.printf("<a href=\"${pluginRoot}/../services/%s\">(%s)</a>", id, id);
} else if (lp instanceof ConfigLoginModuleProvider) {
Map config = lp.options();
Object id = config.get(Constants.SERVICE_PID);
pw.printf("<a href=\"${pluginRoot}/../configMgr/%s\">(Details)</a>", id);
}
pw.printf("</td>");
pw.println("</tr>");
if (rowClass.equals("odd")) {
rowClass = "even";
} else {
rowClass = "odd";
}
}
}
pw.println("</table>");
}
/**
* Creates a wrapper for the given service reference providing read only access to the reference
* properties.
*/
public ReadOnlyDictionary(final ServiceReference serviceReference) {
Hashtable properties = new Hashtable();
final String[] keys = serviceReference.getPropertyKeys();
if (keys != null) {
for (int j = 0; j < keys.length; j++) {
final String key = keys[j];
properties.put(key, serviceReference.getProperty(key));
}
}
m_delegatee = properties;
}
/** @see UserAdminUtil#fireEvent(int, Role) */
@Override
public void fireEvent(int type, Role role) {
if (null == role) {
throw new IllegalArgumentException("parameter role must not be null");
}
ServiceReference<?> reference = userAdminRegistration.getReference();
final UserAdminEvent uaEvent = new UserAdminEvent(reference, type, role);
//
// send event to all listeners, asynchronously - in a separate thread!!
//
UserAdminListener[] eventListeners = listenerService.getServices(new UserAdminListener[0]);
if (null != eventListeners) {
for (Object listenerObject : eventListeners) {
final UserAdminListener listener = (UserAdminListener) listenerObject;
eventExecutor.execute(
new Runnable() {
@Override
public void run() {
listener.roleChanged(uaEvent);
}
});
}
}
//
// send event to EventAdmin if present
//
EventAdmin eventAdmin = m_eventService.getService();
String name = getEventTypeName(type);
if (null != eventAdmin && name != null) {
Dictionary<String, Object> properties = new Hashtable<String, Object>();
properties.put("event", uaEvent);
properties.put("role", role);
properties.put("role.name", role.getName());
properties.put("role.type", role.getType());
properties.put("service", reference);
properties.put("service.id", reference.getProperty(Constants.SERVICE_ID));
properties.put("service.objectClass", reference.getProperty(Constants.OBJECTCLASS));
properties.put("service.pid", reference.getProperty(Constants.SERVICE_PID));
//
Event event = new Event(PaxUserAdminConstants.EVENT_TOPIC_PREFIX + name, properties);
eventAdmin.postEvent(event);
} else {
String message =
"No event service available or incompatible type - cannot send event of type '"
+ name
+ "' for role '"
+ role.getName()
+ "'";
logMessage(this, LogService.LOG_DEBUG, message);
}
}
@Override
public BeanFactory getBeanFactory(Bundle bundle) {
for (ServiceReference ref : bundle.getRegisteredServices()) {
for (String clazz : ((String[]) ref.getProperty("objectClass"))) {
if (clazz.equals(CONTAINER_KEY)) {
return new BeanFactoryBlueprintImpl(
(BlueprintContainer) bundle.getBundleContext().getService(ref));
}
}
}
return null;
}
/**
* * Insert a ServiceReference in a list sorted on cm.ranking property. * *
*
* @param serviceReference The ServiceReference. *
* @param pluginsList The list.
*/
private void insertPluginReference(
ServiceReference serviceReference, int ranking, List pluginsList) {
int i;
for (i = 0; i < pluginsList.size(); ++i) {
ServiceReference nextReference = (ServiceReference) pluginsList.get(i);
Long serviceId = (Long) nextReference.getProperty(Constants.SERVICE_ID);
Integer rankingOfNextReference = (Integer) pluginRankings.get(serviceId);
if (ranking < rankingOfNextReference.intValue()) {
break;
}
}
pluginsList.set(i, serviceReference);
}
/** @param serviceReference */
private void addProvider(ServiceReference serviceReference) {
SolrSearchPropertyProvider provider =
(SolrSearchPropertyProvider)
osgiComponentContext.locateService(SEARCH_PROPERTY_PROVIDER, serviceReference);
Long serviceId = (Long) serviceReference.getProperty(Constants.SERVICE_ID);
propertyProviderById.put(serviceId, provider);
String[] processorNames =
getSetting(serviceReference.getProperty(REG_PROVIDER_NAMES), new String[0]);
for (String processorName : processorNames) {
propertyProvider.put(processorName, provider);
}
}
<T> T getService(URI bundleURI, Class<T> svcClazz) {
Bundle bundle = get().get(bundleURI);
if (bundle == null) {
synchronized (this) {
bundle = startBundle(bundleURI);
}
}
BundleContext ctx = bundle.getBundleContext();
for (ServiceReference<?> ref : bundle.getRegisteredServices()) {
if (ref.isAssignableTo(bundle, svcClazz.getName())) {
return svcClazz.cast(ctx.getService(ref));
}
}
return null;
}
protected void collectSupportedPublishingEvents(
ServiceReference<Portlet> serviceReference, com.liferay.portal.model.Portlet portletModel) {
Set<QName> publishingEvents = new HashSet<>();
PortletApp portletApp = portletModel.getPortletApp();
List<String> supportedPublishingEvents =
StringPlus.asList(serviceReference.getProperty("javax.portlet.supported-publishing-event"));
for (String supportedPublishingEvent : supportedPublishingEvents) {
String name = supportedPublishingEvent;
String qname = null;
String[] parts = StringUtil.split(supportedPublishingEvent, StringPool.SEMICOLON);
if (parts.length == 2) {
name = parts[0];
qname = parts[1];
}
QName qName = getQName(name, qname, portletApp.getDefaultNamespace());
publishingEvents.add(qName);
}
portletModel.setPublishingEvents(publishingEvents);
}
public static String getString(final ServiceReference<?> ref, final String key) {
final Object value = ref.getProperty(key);
if (value instanceof String) {
return (String) value;
}
return null;
}