javax.persistence.spi

Class PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver

java.lang.Object

javax.persistence.spi.PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver

All Implemented Interfaces:

PersistenceProviderResolver

Enclosing class:

PersistenceProviderResolverHolder

private static class PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver
extends java.lang.Object
implements PersistenceProviderResolver

Default provider resolver class to use when none is explicitly set. Uses the META-INF/services approach as described in the Java Persistence specification. A getResources() call is made on the current context classloader to find the service provider files on the classpath. Any service files found are then read to obtain the classes that implement the persistence provider interface.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey Key used for cached persistence providers.
private static interface	PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKeyReference The common interface to get a CacheKey implemented by LoaderReference and PersistenceProviderReference.
private class	PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.LoaderReference References to class loaders are weak references, so that they can be garbage collected when nobody else is using them.
private class	PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference References to persistence provider are soft references so that they can be garbage collected when they have no hard references.
private class	PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.ProviderName A ProviderName captures each provider name found in a service file as well as the URL for the service file it was found in.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.logging.Logger	logger
private static java.lang.String	LOGGER_SUBSYSTEM
private static java.util.regex.Pattern	nonCommentPattern
private java.util.HashMap<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey,PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference>	providers Cached list of available providers cached by CacheKey to ensure there is not potential for provider visibility issues.
private static java.lang.ref.ReferenceQueue	referenceQueue Queue for reference objects referring to class loaders or persistence providers.
private static java.lang.String	SERVICE_PROVIDER_FILE

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DefaultPersistenceProviderResolver()

Method Summary

Modifier and Type	Method and Description
private void	addProviderNames(java.net.URL url, java.util.Collection<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.ProviderName> providerNames) For each services file look for uncommented provider names on each line.
void	clearCachedProviders() Clear all cached providers
private static java.lang.ClassLoader	getContextClassLoader() Wraps Thread.currentThread().getContextClassLoader() into a doPrivileged block if security manager is present
java.util.List<PersistenceProvider>	getPersistenceProviders() Returns a list of the PersistenceProvider implementations available in the runtime environment.
private java.util.Collection<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.ProviderName>	getProviderNames(java.lang.ClassLoader loader) Locate all JPA provider services files and collect all of the provider names available.
private void	log(java.util.logging.Level level, java.lang.String message)
private void	processQueue() Remove garbage collected cache keys & providers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

providers

private volatile java.util.HashMap<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.CacheKey,PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.PersistenceProviderReference> providers

Cached list of available providers cached by CacheKey to ensure there is not potential for provider visibility issues.

referenceQueue

private static final java.lang.ref.ReferenceQueue referenceQueue

Queue for reference objects referring to class loaders or persistence providers.

LOGGER_SUBSYSTEM

private static final java.lang.String LOGGER_SUBSYSTEM

See Also:

Constant Field Values

logger

private java.util.logging.Logger logger

SERVICE_PROVIDER_FILE

private static final java.lang.String SERVICE_PROVIDER_FILE

See Also:

Constant Field Values

nonCommentPattern

private static final java.util.regex.Pattern nonCommentPattern

Constructor Detail

DefaultPersistenceProviderResolver

private DefaultPersistenceProviderResolver()

Method Detail

getPersistenceProviders

public java.util.List<PersistenceProvider> getPersistenceProviders()

Description copied from interface: PersistenceProviderResolver

Returns a list of the PersistenceProvider implementations available in the runtime environment.

Specified by:

getPersistenceProviders in interface PersistenceProviderResolver

Returns:

list of the persistence providers available in the environment

processQueue

private void processQueue()

Remove garbage collected cache keys & providers.

getContextClassLoader

private static java.lang.ClassLoader getContextClassLoader()

Wraps Thread.currentThread().getContextClassLoader() into a doPrivileged block if security manager is present

log

private void log(java.util.logging.Level level,
                 java.lang.String message)

getProviderNames

private java.util.Collection<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.ProviderName> getProviderNames(java.lang.ClassLoader loader)

Locate all JPA provider services files and collect all of the provider names available.

addProviderNames

private void addProviderNames(java.net.URL url,
                              java.util.Collection<PersistenceProviderResolverHolder.DefaultPersistenceProviderResolver.ProviderName> providerNames)

For each services file look for uncommented provider names on each line.

clearCachedProviders

public void clearCachedProviders()

Clear all cached providers

Specified by:

clearCachedProviders in interface PersistenceProviderResolver