org.glassfish.hk2.utilities.ServiceLocatorUtilities Maven / Gradle / Ivy
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package org.glassfish.hk2.utilities;
import java.io.IOException;
import java.io.PrintStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.inject.Singleton;
import org.glassfish.hk2.api.ActiveDescriptor;
import org.glassfish.hk2.api.Context;
import org.glassfish.hk2.api.Descriptor;
import org.glassfish.hk2.api.DescriptorVisibility;
import org.glassfish.hk2.api.DynamicConfiguration;
import org.glassfish.hk2.api.DynamicConfigurationService;
import org.glassfish.hk2.api.Factory;
import org.glassfish.hk2.api.FactoryDescriptors;
import org.glassfish.hk2.api.Filter;
import org.glassfish.hk2.api.HK2Loader;
import org.glassfish.hk2.api.Immediate;
import org.glassfish.hk2.api.IndexedFilter;
import org.glassfish.hk2.api.MultiException;
import org.glassfish.hk2.api.PerThread;
import org.glassfish.hk2.api.Populator;
import org.glassfish.hk2.api.ServiceHandle;
import org.glassfish.hk2.api.ServiceLocator;
import org.glassfish.hk2.api.ServiceLocatorFactory;
import org.glassfish.hk2.api.TypeLiteral;
import org.glassfish.hk2.api.messaging.TopicDistributionService;
import org.glassfish.hk2.internal.DefaultTopicDistributionService;
import org.glassfish.hk2.internal.ImmediateHelper;
import org.glassfish.hk2.internal.PerThreadContext;
/**
* This is a set of useful utilities for working with {@link ServiceLocator}.
*
* @author jwells
*/
public abstract class ServiceLocatorUtilities {
private final static String DEFAULT_LOCATOR_NAME = "default";
/**
* This method will add the ability to use the {@link PerThread} scope to
* the given locator. If the locator already has a {@link Context} implementation
* that handles the {@link PerThread} scope this method does nothing.
*
* @param locator The non-null locator to enable the PerThread scope on
* @throws MultiException if there were errors when committing the service
*/
public static void enablePerThreadScope(ServiceLocator locator) {
Context perThreadContext = locator.getService((new TypeLiteral>() {}).getType());
if (perThreadContext != null) return;
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
final DescriptorImpl descriptor = BuilderHelper.link(PerThreadContext.class).
to(Context.class).
in(Singleton.class.getName()).
visibility(DescriptorVisibility.LOCAL).
build();
ClassLoader loader = ServiceLocatorUtilities.class.getClassLoader();
final ClassLoader binderClassLoader = loader == null ? ClassLoader.getSystemClassLoader() : loader;
descriptor.setLoader(new HK2Loader() {
@Override
public Class loadClass(String className) throws MultiException {
try {
return binderClassLoader.loadClass(className);
} catch (ClassNotFoundException e) {
throw new MultiException(e);
}
}
});
config.bind(descriptor, false);
config.commit();
}
/**
* This method will add the ability to use the {@link Immediate} scope to
* the given locator. If the locator already has a {@link Context} implementation
* that handles the {@link Immediate} scope this method does nothing.
*
* This implementation of {@link Immediate} scope will use a separate thread for
* instantiating services. Any failures from {@link Immediate} scoped services
* will be given to the current set of {@link ImmediateErrorHandler} implementations
*
* @param locator The non-null locator to enable the Immediate scope on
* @throws MultiException if there were errors when committing the service
*/
public static void enableImmediateScope(ServiceLocator locator) {
List> immediateContexts = locator.getAllServiceHandles((new TypeLiteral>() {}).getType());
for (ServiceHandle immediateContext : immediateContexts) {
ActiveDescriptor contextDescriptor = immediateContext.getActiveDescriptor();
if (contextDescriptor.getLocatorId() == locator.getLocatorId()) return;
}
addClasses(locator, ImmediateContext.class, ImmediateHelper.class);
}
/**
* This method will bind all of the binders given together in a
* single config transaction.
*
* @param locator The non-null locator to use for the configuration action
* @param binders The non-null list of binders to be added to the locator
* @throws MultiException if any error was encountered while binding services
*/
public static void bind(ServiceLocator locator, Binder... binders) {
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
for (Binder binder : binders) {
binder.bind(config);
}
config.commit();
}
/**
* This method will create or find a ServiceLocator with the given name and
* bind all of the binders given together in a single config transaction.
*
* @param name The non-null name of the locator to use for the configuration action
* @param binders The non-null list of binders to be added to the locator
* @return The service locator that was either found or created
* @throws MultiException if any error was encountered while binding services
*/
public static ServiceLocator bind(String name, Binder... binders) {
ServiceLocatorFactory factory = ServiceLocatorFactory.getInstance();
ServiceLocator locator = factory.create(name);
bind(locator, binders);
return locator;
}
/**
* This method will create or find a ServiceLocator with the name "default" and
* bind all of the binders given together in a single config transaction.
*
* @param binders The non-null list of binders to be added to the locator
* @return The service locator that was either found or created
* @throws MultiException if any error was encountered while binding services
*/
public static ServiceLocator bind(Binder... binders) {
return bind(DEFAULT_LOCATOR_NAME, binders);
}
/**
* This method adds one existing object to the given service locator. The caller
* of this will not get a chance to customize the descriptor that goes into the
* locator, and hence must rely completely on the analysis of the system to determine
* the set of contracts and metadata associated with the descriptor. The same algorithm
* is used in this method as in the {@link BuilderHelper#createConstantDescriptor(Object)}
* method.
*
* @param locator The non-null locator to add this descriptor to
* @param constant The non-null constant to add to the service locator
* @return The descriptor that was added to the service locator
*/
public static ActiveDescriptor addOneConstant(ServiceLocator locator, Object constant) {
if (locator == null || constant == null) throw new IllegalArgumentException();
return addOneDescriptor(locator, BuilderHelper.createConstantDescriptor(constant), false);
}
/**
* This method adds one existing object to the given service locator. The caller
* of this will not get a chance to customize the descriptor that goes into the
* locator, and hence must rely completely on the analysis of the system to determine
* the set of contracts and metadata associated with the descriptor. The same algorithm
* is used in this method as in the {@link BuilderHelper#createConstantDescriptor(Object)}
* method.
*
* @param locator The non-null locator to add this descriptor to
* @param constant The non-null constant to add to the service locator
* @param name The name this descriptor should take (may be null)
* @param contracts The full set of contracts this descriptor should take. If this
* field is the empty set then the contracts will be automatically discovered
* @return The descriptor that was added to the service locator
*/
public static ActiveDescriptor addOneConstant(ServiceLocator locator, Object constant, String name, Type... contracts) {
if (locator == null || constant == null) throw new IllegalArgumentException();
return addOneDescriptor(locator, BuilderHelper.createConstantDescriptor(constant, name, contracts), false);
}
/**
* It is very often the case that one wishes to add a single descriptor to
* a service locator. This method adds that one descriptor. If the descriptor
* is an {@link ActiveDescriptor} and is reified, it will be added as an
* {@link ActiveDescriptor}. Otherwise it will be bound as a {@link Descriptor}.
* A deep copy will be made of the descriptor passed in
*
* @param locator The non-null locator to add this descriptor to
* @param descriptor The non-null descriptor to add to this locator
* @return The descriptor that was added to the system
* @throws MultiException On a commit failure
*/
public static ActiveDescriptor addOneDescriptor(ServiceLocator locator, Descriptor descriptor) {
return addOneDescriptor(locator, descriptor, true);
}
/**
* It is very often the case that one wishes to add a single descriptor to
* a service locator. This method adds that one descriptor. If the descriptor
* is an {@link ActiveDescriptor} and is reified, it will be added as an
* {@link ActiveDescriptor}. Otherwise it will be bound as a {@link Descriptor}.
*
* @param locator The non-null locator to add this descriptor to
* @param descriptor The non-null descriptor to add to this locator
* @param requiresDeepCopy If true a deep copy will be made of the
* key. If false then the Descriptor will be used as is, and it
* is the responsibility of the caller to ensure that the fields
* of the Descriptor never change (with the exception of any
* writeable fields, such as ranking)
* @return The descriptor that was added to the system
* @throws MultiException On a commit failure
*/
@SuppressWarnings("unchecked")
public static ActiveDescriptor addOneDescriptor(ServiceLocator locator, Descriptor descriptor,
boolean requiresDeepCopy) {
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
ActiveDescriptor retVal;
if (descriptor instanceof ActiveDescriptor) {
ActiveDescriptor active = (ActiveDescriptor) descriptor;
if (active.isReified()) {
retVal = config.addActiveDescriptor(active, requiresDeepCopy);
}
else {
retVal = config.bind(descriptor, requiresDeepCopy);
}
}
else {
retVal = config.bind(descriptor, requiresDeepCopy);
}
config.commit();
return retVal;
}
/**
* Adds the given factory descriptors to the service locator
*
* @param locator The locator to add the factories to. May not be null
* @param factories The list of factory descriptors to add to the system. May not be null
* @return a list of the FactoryDescriptor descriptors that were added to the service locator
* @throws MultiException On a commit failure
*/
public static List addFactoryDescriptors(ServiceLocator locator, FactoryDescriptors...factories) {
return addFactoryDescriptors(locator, true, factories);
}
/**
* Adds the given factory descriptors to the service locator
*
* @param locator The locator to add the factories to. May not be null
* @param requiresDeepCopy This is false ONLY if every one of the factories given to this method can be used without a copy
* @param factories The list of factory descriptors to add to the system. May not be null
* @return A list of the FactoryDescriptor descriptors that were added to the service locator
* @throws MultiException On a commit failure
*/
public static List addFactoryDescriptors(ServiceLocator locator, boolean requiresDeepCopy, FactoryDescriptors... factories) {
if (factories == null || locator == null) throw new IllegalArgumentException();
List retVal = new ArrayList(factories.length);
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
for (FactoryDescriptors factory : factories) {
FactoryDescriptors addMe = config.bind(factory, requiresDeepCopy);
retVal.add(addMe);
}
config.commit();
return retVal;
}
/**
* It is very often the case that one wishes to add classes that hk2
* will automatically analyze for contracts and qualifiers to
* a service locator. This method adds those classes.
*
* If the class to add implements {@link Factory} then two descriptors
* will be added, one for the {@link Factory} class itself, and one for
* the {@link Factory#provide()} method of the factory. In the output
* list the descriptor for the {@link Factory} will be added first, followed
* by the descriptor for the {@link Factory#provide()} method
*
* @param locator The non-null locator to add this descriptor to
* @param toAdd The classes to add to the locator. If a class in this list implements
* {@link Factory} then two descriptors will be added for that class
* @return The list of descriptors added to the system. Will not return null but
* may return an empty list
* @throws MultiException On a commit failure
*/
@SuppressWarnings("unchecked")
public static List> addClasses(ServiceLocator locator, Class... toAdd) {
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
LinkedList> retVal = new LinkedList>();
for (Class addMe : toAdd) {
if (Factory.class.isAssignableFrom(addMe)) {
FactoryDescriptors fds = config.addActiveFactoryDescriptor((Class>) addMe);
retVal.add((ActiveDescriptor) fds.getFactoryAsAService());
retVal.add((ActiveDescriptor) fds.getFactoryAsAFactory());
}
else {
ActiveDescriptor ad = config.addActiveDescriptor(addMe);
retVal.add(ad);
}
}
config.commit();
return retVal;
}
/* package */ static String getBestContract(Descriptor d) {
String impl = d.getImplementation();
Set contracts = d.getAdvertisedContracts();
if (contracts.contains(impl)) return impl;
for (String candidate : contracts) {
return candidate;
}
return impl;
}
/**
* Finds a descriptor in the given service locator. If the descriptor has the serviceId and
* locatorId set then it will first attempt to use those values to get the exact descriptor
* described by the input descriptor. Failing that (or if the input descriptor does not have
* those values set) then it will use the equals algorithm of {@DescriptorImpl} to determine
* the equality of the descriptor.
*
* @param locator The non-null locator in which to find the descriptor
* @param descriptor The non-null descriptor to search for
* @return The descriptor as found in the locator, or null if no such descriptor could be found
*/
@SuppressWarnings("unchecked")
public static ActiveDescriptor findOneDescriptor(ServiceLocator locator, Descriptor descriptor) {
if (locator == null || descriptor == null) throw new IllegalArgumentException();
if (descriptor.getServiceId() != null && descriptor.getLocatorId() != null) {
ActiveDescriptor retVal = (ActiveDescriptor) locator.getBestDescriptor(
BuilderHelper.createSpecificDescriptorFilter(descriptor));
if (retVal != null) return retVal;
// Fall back to DescriptorImpl.equals
}
final DescriptorImpl di;
if (descriptor instanceof DescriptorImpl) {
di = (DescriptorImpl) descriptor;
}
else {
di = new DescriptorImpl(descriptor);
}
final String contract = getBestContract(descriptor);
final String name = descriptor.getName();
ActiveDescriptor retVal = (ActiveDescriptor) locator.getBestDescriptor(new IndexedFilter() {
@Override
public boolean matches(Descriptor d) {
return di.equals(d);
}
@Override
public String getAdvertisedContract() {
return contract;
}
@Override
public String getName() {
return name;
}
});
return retVal;
}
/**
* This method will attempt to remove descriptors matching the passed in descriptor from
* the given locator. If the descriptor has its locatorId and serviceId values set then
* only a descriptor matching those exact locatorId and serviceId will be removed. Otherwise
* any descriptor that returns true from the {@link DescriptorImpl#equals(Object)} method
* will be removed from the locator. Note that if more than one descriptor matches they
* will all be removed. Hence more than one descriptor may be removed by this method.
*
* @param locator The non-null locator to remove the descriptor from
* @param descriptor The non-null descriptor to remove from the locator
*/
public static void removeOneDescriptor(ServiceLocator locator, Descriptor descriptor) {
removeOneDescriptor(locator, descriptor, false);
}
/**
* This method will attempt to remove descriptors matching the passed in descriptor from
* the given locator. If the descriptor has its locatorId and serviceId values set then
* only a descriptor matching those exact locatorId and serviceId will be removed. Otherwise
* any descriptor that returns true from the {@link DescriptorImpl#equals(Object)} method
* will be removed from the locator. Note that if more than one descriptor matches they
* will all be removed. Hence more than one descriptor may be removed by this method.
*
* @param locator The non-null locator to remove the descriptor from
* @param descriptor The non-null descriptor to remove from the locator
* @param includeAliasDescriptors If set to true all {@link AliasDescriptor}s that point
* to any descriptors found by filter will also be removed
*/
public static void removeOneDescriptor(ServiceLocator locator, Descriptor descriptor, boolean includeAliasDescriptors) {
if (locator == null || descriptor == null) throw new IllegalArgumentException();
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
if (descriptor.getLocatorId() != null && descriptor.getServiceId() != null) {
Filter destructionFilter = BuilderHelper.createSpecificDescriptorFilter(descriptor);
config.addUnbindFilter(destructionFilter);
if (includeAliasDescriptors == true) {
List> goingToDie = locator.getDescriptors(destructionFilter);
if (!goingToDie.isEmpty()) {
AliasFilter af = new AliasFilter(goingToDie);
config.addUnbindFilter(af);
}
}
config.commit();
return;
}
// Must use second algorithm, which is not as precise, but which still mainly works
final DescriptorImpl di;
if (descriptor instanceof DescriptorImpl) {
di = (DescriptorImpl) descriptor;
}
else {
di = new DescriptorImpl(descriptor);
}
Filter destructionFilter = new Filter() {
@Override
public boolean matches(Descriptor d) {
return di.equals(d);
}
};
config.addUnbindFilter(destructionFilter);
if (includeAliasDescriptors == true) {
List> goingToDie = locator.getDescriptors(destructionFilter);
if (!goingToDie.isEmpty()) {
AliasFilter af = new AliasFilter(goingToDie);
config.addUnbindFilter(af);
}
}
config.commit();
}
/**
* Removes all the descriptors from the given locator that match the
* given filter
*
* @param locator The non-null locator to remove the descriptors from
* @param filter The non-null filter which will determine what descriptors to remove
*/
public static void removeFilter(ServiceLocator locator, Filter filter) {
removeFilter(locator, filter, false);
}
/**
* Removes all the descriptors from the given locator that match the
* given filter
*
* @param locator The non-null locator to remove the descriptors from
* @param filter The non-null filter which will determine what descriptors to remove
* @param includeAliasDescriptors If set to true all {@link AliasDescriptor}s that point
* to any descriptors found by filter will also be removed
*/
public static void removeFilter(ServiceLocator locator, Filter filter, boolean includeAliasDescriptors) {
if (locator == null || filter == null) throw new IllegalArgumentException();
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
DynamicConfiguration config = dcs.createDynamicConfiguration();
config.addUnbindFilter(filter);
if (includeAliasDescriptors == true) {
List> goingToDie = locator.getDescriptors(filter);
if (!goingToDie.isEmpty()) {
AliasFilter af = new AliasFilter(goingToDie);
config.addUnbindFilter(af);
}
}
config.commit();
}
/**
* Returns the best service matching the passed in fully qualified
* class name of the service
*
* @param locator The locator to find the service in
* @param className The fully qualified class name of the service
* @return The found service, or null if there is no service with this class name
*/
@SuppressWarnings("unchecked")
public static T getService(ServiceLocator locator, String className) {
if (locator == null || className == null) throw new IllegalArgumentException();
ActiveDescriptor ad = (ActiveDescriptor) locator.getBestDescriptor(BuilderHelper.createContractFilter(className));
if (ad == null) return null;
return locator.getServiceHandle(ad).getService();
}
/**
* Returns the service in this service locator given the current descriptor.
*
* @param locator The non-null locator in which to get the service associated with
* this descriptor
* @param descriptor The non-null descriptor to find the corresponding service for
* @return The service object
*/
@SuppressWarnings("unchecked")
public static T getService(ServiceLocator locator, Descriptor descriptor) {
if (locator == null || descriptor == null) throw new IllegalArgumentException();
Long locatorId = descriptor.getLocatorId();
if (locatorId != null &&
(locatorId.longValue() == locator.getLocatorId()) &&
(descriptor instanceof ActiveDescriptor)) {
return locator.getServiceHandle((ActiveDescriptor) descriptor).getService();
}
ActiveDescriptor found = findOneDescriptor(locator, descriptor);
if (found == null) return null;
return locator.getServiceHandle(found).getService();
}
/**
* This method returns a {@link DynamicConfiguration} for use with adding
* and removing services to the given {@link ServiceLocator}.
*
* @param locator A non-null locator to get a DynamicConfiguration for
* @return A non-null DynamicConfiguration object that can be used to add
* or remove services to the passed in locator
* @throws IllegalStateException If there was an error retrieving the
* {@link DynamicConfigurationService} for this locator
*/
public static DynamicConfiguration createDynamicConfiguration(ServiceLocator locator)
throws IllegalStateException {
if (locator == null) throw new IllegalArgumentException();
DynamicConfigurationService dcs = locator.getService(DynamicConfigurationService.class);
if (dcs == null) throw new IllegalStateException();
return dcs.createDynamicConfiguration();
}
/**
* This method will first attempt to find a service corresponding to the type and qualifiers
* passed in to the method, and if one is found simply returns it. If no service is found
* in the locator this method will call {@link ServiceLocator#createAndInitialize(Class)} on
* the class (ignoring the qualifiers) in order to create an instance of the service.
*
* @param locator The service locator to search for the service with
* @param type The non-null type of object to either find or create
* @param qualifiers The set of qualifiers that should be associated with the service
* @return An instance of type as either found in the locator or automatically created,
* injected and post-constructed. Note that the return value CAN be null IF the service
* was found in the service locator and the context in which the service is in allows for
* null services.
* @throws MultiException On a failure from any of the underlying operations
*/
public static T findOrCreateService(ServiceLocator locator, Class type, Annotation... qualifiers) throws MultiException {
if (locator == null || type == null) throw new IllegalArgumentException();
ServiceHandle retVal = locator.getServiceHandle(type, qualifiers);
if (retVal == null) {
return locator.createAndInitialize(type);
}
return retVal.getService();
}
/**
* Gets one value from a metadata field from the given descriptor
*
* @param d The non-null descriptor from which to get the first value in the given field
* @param field The non-null field to get the first value of
* @return The first value in the given field, or null if no such field exists in the descriptor
*/
public static String getOneMetadataField(Descriptor d, String field) {
Map> metadata = d.getMetadata();
List values = metadata.get(field);
if (values == null || values.isEmpty()) return null;
return values.get(0);
}
/**
* Gets one value from a metadata field from the given service handle
*
* @param h The non-null service handle from which to get the first value in the given field
* @param field The non-null field to get the first value of
* @return The first value in the given field, or null if no such field exists in the descriptor
*/
public static String getOneMetadataField(ServiceHandle h, String field) {
return getOneMetadataField(h.getActiveDescriptor(), field);
}
/**
* This method is often the first line of a stand-alone client that wishes to use HK2.
* It creates a ServiceLocator with the given name (or a randomly generated name if
* null is passed in) and then populates that service locator with services found in
* the META-INF/hk2-locator/default files that can be found with the classloader that
* loaded HK2 (usually the system classloader).
*
* @param name The name of the service locator to create. If there is already a service
* locator of this name this method will use that one to populate. If this is null
* a randomly assigned name will be given to the service locator, and it will not be
* tracked by the system. If this is NOT null then this service locator can be found
* with {@link ServiceLocatorFactory#find(String)}.
* @return A service locator that has been populated with services
* @throws MultiException If there was a failure when populating or creating the ServiceLocator
*/
public static ServiceLocator createAndPopulateServiceLocator(String name) throws MultiException {
ServiceLocator retVal = ServiceLocatorFactory.getInstance().create(name);
DynamicConfigurationService dcs = retVal.getService(DynamicConfigurationService.class);
Populator populator = dcs.getPopulator();
try {
populator.populate();
}
catch (IOException e) {
throw new MultiException(e);
}
return retVal;
}
/**
* This method is often the first line of a stand-alone client that wishes to use HK2.
* It creates a ServiceLocator with a randomly generated name and then populates that
* service locator with services found in the META-INF/hk2-locator/default files that
* can be found with the classloader that loaded HK2 (usually the system classloader).
*
* @return A service locator that has been populated with services
* @throws MultiException If there was a failure when populating or creating the ServiceLocator
*/
public static ServiceLocator createAndPopulateServiceLocator() {
return createAndPopulateServiceLocator(null);
}
private static class AliasFilter implements Filter {
private final Set values = new HashSet();
private AliasFilter(List> bases) {
for (ActiveDescriptor base : bases) {
String val = base.getLocatorId() + "." + base.getServiceId();
values.add(val);
}
}
@Override
public boolean matches(Descriptor d) {
List mAliasVals = d.getMetadata().get(AliasDescriptor.ALIAS_METADATA_MARKER);
if (mAliasVals == null || mAliasVals.isEmpty()) return false;
String aliasVal = mAliasVals.get(0);
return values.contains(aliasVal);
}
}
/**
* This method will cause lookup operations to throw exceptions when
* exceptions are encountered in underlying operations such as
* classloading. This method is idempotent. This method works
* by adding {@link RethrowErrorService} to the service registry
*
* Do not use this methods in secure applications where callers to lookup
* should not be given the information that they do NOT have access
* to a service
*
* @param locator The service locator to enable lookup exceptions on. May not be null
*/
public static void enableLookupExceptions(ServiceLocator locator) {
if (locator == null) throw new IllegalArgumentException();
if (locator.getService(RethrowErrorService.class) != null) return;
addClasses(locator, RethrowErrorService.class);
}
/**
* This method will enable the default topic distribution service.
*
* The default distribution service distributes messages on the
* same thread as the caller of {@link org.glassfish.hk2.api.messaging.Topic#publish(Object)}
* and (TBD security policy). Objects to be distributed to will be
* held with SoftReferences, and hence if they go out of scope they
* will not be distributed to. Only services created AFTER the topic
* distribution service is enabled will be distributed to.
*
* This method is idempotent, so that if there is already a
* TopicDistributionService with the default name is available this method
* will do nothing
*
* @param locator The service locator to enable topic distribution on. May not be null
*/
public static void enableTopicDistribution(ServiceLocator locator) {
if (locator == null) throw new IllegalArgumentException();
if (locator.getService(TopicDistributionService.class, TopicDistributionService.HK2_DEFAULT_TOPIC_DISTRIBUTOR) != null) {
// Will not add it a second time
return;
}
addClasses(locator, DefaultTopicDistributionService.class);
}
/**
* Dumps all descriptors in this ServiceLocator to stderr
*
* @param locator The non-null locator to dump to stderr
*/
public static void dumpAllDescriptors(ServiceLocator locator) {
dumpAllDescriptors(locator, System.err);
}
/**
* Dumps all descriptors in this ServiceLocator to the given PrintStream
*
* @param locator The non-null locator to dump
* @param output The non-null PrintStream to print the descriptors to
*/
public static void dumpAllDescriptors(ServiceLocator locator, PrintStream output) {
if (locator == null || output == null) throw new IllegalArgumentException();
List> all = locator.getDescriptors(BuilderHelper.allFilter());
for (ActiveDescriptor d : all) {
output.println(d.toString());
}
}
}