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package org.glassfish.hk2.internal;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.ServiceConfigurationError;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.glassfish.hk2.api.ServiceLocator;
import org.glassfish.hk2.api.ServiceLocatorFactory;
import org.glassfish.hk2.api.ServiceLocatorListener;
import org.glassfish.hk2.extension.ServiceLocatorGenerator;
import org.glassfish.hk2.osgiresourcelocator.ServiceLoader;
/**
* The implementation of the {@link ServiceLocatorFactory} that looks
* in the OSGi service registry or the META-INF/services for the implementation
* to use. Failing those things, it uses the standard default locator
* generator, which is found in auto-depends, which is the 99.9% case
*
* @author jwells
*/
public class ServiceLocatorFactoryImpl extends ServiceLocatorFactory {
private static final Object sLock = new Object();
private static int name_count = 0;
private static final String GENERATED_NAME_PREFIX = "__HK2_Generated_";
private final ServiceLocatorGenerator defaultGenerator;
private final Object lock = new Object();
private final HashMap<String, ServiceLocator> serviceLocators = new HashMap<String, ServiceLocator>();
private final HashSet<ServiceLocatorListener> listeners = new HashSet<ServiceLocatorListener>();
private static Logger logger = Logger.getLogger(ServiceLocatorFactoryImpl.class.getPackage().getName());
/**
* This will create a new set of name to locator mappings
*/
public ServiceLocatorFactoryImpl() {
defaultGenerator = AccessController.doPrivileged(new PrivilegedAction<ServiceLocatorGenerator>() {
@Override
public ServiceLocatorGenerator run() {
try {
return getGenerator();
}
catch (Throwable th) {
Logger.getLogger(ServiceLocatorFactoryImpl.class.getName()).warning("Error finding implementation of hk2: " + th.getMessage());
// th.printStackTrace();
// Thread.dumpStack();
return null;
}
}
});
}
private static Iterable<? extends ServiceLocatorGenerator> getOSGiSafeGenerators() {
try {
return ServiceLoader.lookupProviderInstances(ServiceLocatorGenerator.class);
}
catch (Throwable th) {
// The bundle providing ServiceLoader need not be on the classpath
return null;
}
}
private static ServiceLocatorGenerator getGenerator() {
Iterable<? extends ServiceLocatorGenerator> generators = getOSGiSafeGenerators();
if (generators != null) {
// non-null indicates we are in OSGi environment
// So, we will return whatever we find. If we don't find anything here, then we assume it is a
// configuration error and return null.
// Since org.glassfish.hk2.osgiresourcelocator.ServiceLoader never throws ServiceConfigurationError,
// there is no need to catch it and try next item in the iterator.
final Iterator<? extends ServiceLocatorGenerator> iterator = generators.iterator();
return iterator.hasNext() ? iterator.next() : null;
}
// We are in non-OSGi environment, let's use JDK ServiceLoader instead.
// Make sure we use our current loader to locate the service as opposed to some arbitrary TCL
final ClassLoader classLoader = ServiceLocatorFactoryImpl.class.getClassLoader();
Iterator<ServiceLocatorGenerator> providers = java.util.ServiceLoader.load(ServiceLocatorGenerator.class,
classLoader).iterator();
while (providers.hasNext()) {
try {
return providers.next();
} catch (ServiceConfigurationError sce) {
// This can happen. See the exception javadoc for more details.
logger.logp(Level.FINE, "ServiceLocatorFactoryImpl", "getGenerator",
"Exception while looking up service locator generator", sce);
// We will try the next one
}
}
logger.warning("Cannot find a default implementation of the HK2 ServiceLocatorGenerator");
return null;
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.ServiceLocatorFactory#create(java.lang.String, org.glassfish.hk2.api.Module)
*/
@Override
public ServiceLocator create(String name) {
return create(name, null, null, CreatePolicy.RETURN);
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.ServiceLocatorFactory#find(java.lang.String)
*/
@Override
public ServiceLocator find(String name) {
synchronized (lock) {
return serviceLocators.get(name);
}
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.ServiceLocatorFactory#destroy(java.lang.String)
*/
@Override
public void destroy(String name) {
ServiceLocator killMe = null;
synchronized (lock) {
killMe = serviceLocators.remove(name);
if (killMe != null) {
for (ServiceLocatorListener listener : listeners) {
try {
listener.listenerDestroyed(killMe);
}
catch (Throwable th) {
logger.log(Level.FINE, "Exception thrown from listenerDestroyed method of " + listener, th);
}
}
}
}
if (killMe != null) {
killMe.shutdown();
}
}
public void destroy(ServiceLocator locator) {
if (locator == null) return;
locator.shutdown();
destroy(locator.getName()); // Removes it from our DB
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.ServiceLocatorFactory#create(java.lang.String, org.glassfish.hk2.api.Module, org.glassfish.hk2.api.ServiceLocator)
*/
@Override
public ServiceLocator create(String name,
ServiceLocator parent) {
return create(name, parent, null, CreatePolicy.RETURN);
}
private static String getGeneratedName() {
synchronized (sLock) {
return GENERATED_NAME_PREFIX + name_count++;
}
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.ServiceLocatorFactory#create(java.lang.String, org.glassfish.hk2.api.ServiceLocator, org.glassfish.hk2.extension.ServiceLocatorGenerator)
*/
@Override
public ServiceLocator create(String name, ServiceLocator parent,
ServiceLocatorGenerator generator) {
return create(name, parent, generator, CreatePolicy.RETURN);
}
@Override
public ServiceLocator create(String name, ServiceLocator parent,
ServiceLocatorGenerator generator, CreatePolicy policy) {
synchronized (lock) {
ServiceLocator retVal;
if (name == null) {
name = getGeneratedName();
return internalCreate(name, parent, generator);
}
retVal = serviceLocators.get(name);
if (retVal != null) {
if (policy == null || CreatePolicy.RETURN.equals(policy)) {
return retVal;
}
if (policy.equals(CreatePolicy.DESTROY)) {
destroy(retVal);
}
else {
throw new IllegalStateException(
"A ServiceLocator named " + name + " already exists");
}
}
retVal = internalCreate(name, parent, generator);
serviceLocators.put(name, retVal);
for (ServiceLocatorListener listener : listeners) {
try {
listener.listenerAdded(retVal);
}
catch (Throwable th) {
logger.log(Level.FINE, "Exception thrown from listenerAdded method of " + listener, th);
}
}
return retVal;
}
}
private ServiceLocator internalCreate(String name, ServiceLocator parent, ServiceLocatorGenerator generator) {
if (generator == null) {
if (defaultGenerator == null) {
throw new IllegalStateException("No generator was provided and there is no default generator registered");
}
generator = defaultGenerator;
}
return generator.create(name, parent);
}
@Override
public void addListener(ServiceLocatorListener listener) {
if (listener == null) throw new IllegalArgumentException();
synchronized (lock) {
if (listeners.contains(listener)) return;
try {
HashSet<ServiceLocator> currentLocators = new HashSet<ServiceLocator>(serviceLocators.values());
listener.initialize(Collections.unmodifiableSet(currentLocators));
}
catch (Throwable th) {
// Not added to the set of listeners
logger.log(Level.FINE, "Exception thrown from init method of " + listener, th);
return;
}
listeners.add(listener);
}
}
@Override
public void removeListener(ServiceLocatorListener listener) {
if (listener == null) throw new IllegalArgumentException();
synchronized (lock) {
listeners.remove(listener);
}
}
}