jpa/subsystem/src/main/java/org/jboss/as/jpa/processor/PersistenceRefProcessor.java
private List<BindingConfiguration> getPersistenceContextRefs(DeploymentUnit deploymentUnit, DeploymentDescriptorEnvironment environment, ClassLoader classLoader, DeploymentReflectionIndex deploymentReflectionIndex, ResourceInjectionTarget resourceInjectionTarget) throws
        DeploymentUnitProcessingException {

        List<BindingConfiguration> bindingConfigurations = new ArrayList<BindingConfiguration>();
        final RemoteEnvironment remoteEnvironment = environment.getEnvironment();
        if (remoteEnvironment == null) {
            return bindingConfigurations;
        }

        if (remoteEnvironment instanceof Environment) {
            PersistenceContextReferencesMetaData persistenceUnitRefs = ((Environment) remoteEnvironment).getPersistenceContextRefs();

            if (persistenceUnitRefs != null) {
                for (PersistenceContextReferenceMetaData puRef : persistenceUnitRefs) {
                    String name = puRef.getName();
                    String persistenceUnitName = puRef.getPersistenceUnitName();
                    String lookup = puRef.getLookupName();

                    if (!isEmpty(lookup) && !isEmpty(persistenceUnitName)) {
                        throw JpaLogger.ROOT_LOGGER.cannotSpecifyBoth("<lookup-name>", lookup, "persistence-unit-name", persistenceUnitName, "<persistence-context-ref/>", resourceInjectionTarget);
                    }
                    if (!name.startsWith("java:")) {
                        name = environment.getDefaultContext() + name;
                    }

                    // our injection (source) comes from the local (ENC) lookup, no matter what.
                    LookupInjectionSource injectionSource = new LookupInjectionSource(name);
                    //add any injection targets
                    processInjectionTargets(resourceInjectionTarget, injectionSource, classLoader, deploymentReflectionIndex, puRef, EntityManager.class);

                    BindingConfiguration bindingConfiguration = null;
                    if (!isEmpty(lookup)) {
                        bindingConfiguration = new BindingConfiguration(name, new LookupInjectionSource(lookup));
                    } else {
                        PropertiesMetaData properties = puRef.getProperties();
                        Map<String, String> map = new HashMap<>();
                        if (properties != null) {
                            for (PropertyMetaData prop : properties) {
                                map.put(prop.getKey(), prop.getValue());
                            }
                        }
                        PersistenceContextType type = (puRef.getPersistenceContextType() == null || puRef.getPersistenceContextType() == PersistenceContextTypeDescription.TRANSACTION) ? PersistenceContextType.TRANSACTION : PersistenceContextType.EXTENDED ;
                        SynchronizationType synchronizationType =
                                (puRef.getPersistenceContextSynchronization() == null || PersistenceContextSynchronizationType.Synchronized.equals(puRef.getPersistenceContextSynchronization()))?
                                        SynchronizationType.SYNCHRONIZED: SynchronizationType.UNSYNCHRONIZED;
                        InjectionSource pcBindingSource = this.getPersistenceContextBindingSource(deploymentUnit, persistenceUnitName, type, synchronizationType, map);
                        bindingConfiguration = new BindingConfiguration(name, pcBindingSource);
                    }
                    bindingConfigurations.add(bindingConfiguration);
                }
            }
        }
        return bindingConfigurations;
    }
private List<BindingConfiguration> getPersistenceContextRefs(DeploymentUnit deploymentUnit, DeploymentDescriptorEnvironment environment, ClassLoader classLoader, DeploymentReflectionIndex deploymentReflectionIndex, ResourceInjectionTarget resourceInjectionTarget) throws
        DeploymentUnitProcessingException {

        List<BindingConfiguration> bindingConfigurations = new ArrayList<BindingConfiguration>();
        final RemoteEnvironment remoteEnvironment = environment.getEnvironment();
        if (remoteEnvironment == null) {
            return bindingConfigurations;
        }

        if (remoteEnvironment instanceof Environment) {
            PersistenceContextReferencesMetaData persistenceUnitRefs = ((Environment) remoteEnvironment).getPersistenceContextRefs();

            if (persistenceUnitRefs != null) {
                for (PersistenceContextReferenceMetaData puRef : persistenceUnitRefs) {
                    String name = puRef.getName();
                    String persistenceUnitName = puRef.getPersistenceUnitName();
                    String lookup = puRef.getLookupName();

                    if (!isEmpty(lookup) && !isEmpty(persistenceUnitName)) {
                        throw JpaLogger.ROOT_LOGGER.cannotSpecifyBoth("<lookup-name>", lookup, "persistence-unit-name", persistenceUnitName, "<persistence-context-ref/>", resourceInjectionTarget);
                    }
                    if (!name.startsWith("java:")) {
                        name = environment.getDefaultContext() + name;
                    }

                    // our injection (source) comes from the local (ENC) lookup, no matter what.
                    LookupInjectionSource injectionSource = new LookupInjectionSource(name);
                    //add any injection targets
                    processInjectionTargets(resourceInjectionTarget, injectionSource, classLoader, deploymentReflectionIndex, puRef, EntityManager.class);

                    BindingConfiguration bindingConfiguration = null;
                    if (!isEmpty(lookup)) {
                        bindingConfiguration = new BindingConfiguration(name, new LookupInjectionSource(lookup));
                    } else {
                        PropertiesMetaData properties = puRef.getProperties();
                        Map<String, String> map = new HashMap<>();
                        if (properties != null) {
                            for (PropertyMetaData prop : properties) {
                                map.put(prop.getKey(), prop.getValue());
                            }
                        }
                        PersistenceContextType type = (puRef.getPersistenceContextType() == null || puRef.getPersistenceContextType() == PersistenceContextTypeDescription.TRANSACTION) ? PersistenceContextType.TRANSACTION : PersistenceContextType.EXTENDED ;
                        SynchronizationType synchronizationType =
                                (puRef.getPersistenceContextSynchronization() == null || PersistenceContextSynchronizationType.Synchronized.equals(puRef.getPersistenceContextSynchronization()))?
                                        SynchronizationType.SYNCHRONIZED: SynchronizationType.UNSYNCHRONIZED;
                        InjectionSource pcBindingSource = this.getPersistenceContextBindingSource(deploymentUnit, persistenceUnitName, type, synchronizationType, map);
                        bindingConfiguration = new BindingConfiguration(name, pcBindingSource);
                    }
                    bindingConfigurations.add(bindingConfiguration);
                }
            }
        }
        return bindingConfigurations;
    }
Resolves persistence-unit-ref

@param environment               The environment to resolve the elements for
@param classLoader               The deployment class loader
@param deploymentReflectionIndex The reflection index
@return The bindings for the environment entries