Cari utenti,
nella mia web abb Java utilizzo JPA. Il progetto è creato in Eclipse e l'applicazione server è TomEE. Ho creato la connessione nel file tomee.xml in modo corretto (nel log dell'avvio del server vedo la connessione regolarmente). Ho creato il file persistence.xml; tuttavia, se aggiungo la riga seguente al mio codice nel bean che deve gestire le operazioni di CRUD, il server nemmeno si avvia e mostra un messaggio di errore. Sono due giorni che non riesco a risolvere, chi sarà l'eroe capace di farlo? Grazie infinite a tutti!

Riga che genera l'errore:
codice:
@PersistenceContext(unitName="myPersistence")
Persistence.xml:
codice:
<persistencexmlns="http://java.sun.com/xml/ns/persistence"version="1.0">

<persistence-unitname="myPersistence">


<jta-data-source>connessioneCorsoWeb</jta-data-source>
<properties>
<propertyname="openejb.jpa.auto-scan"value="true"/>
<!-- <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)" /> -->
</properties>
</persistence-unit>
</persistence>
Messaggio di errore:
codice:
GRAVE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso_web]]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:192)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:941)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1421)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1411)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso_web]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
    ... 6 more
Caused by: java.lang.NoSuchMethodError: javax.persistence.PersistenceContext.synchronization()Ljavax/persistence/SynchronizationType;
    at org.apache.openejb.config.PersistenceContextAnnFactory$DirectPersistenceContext.synchronization(PersistenceContextAnnFactory.java:118)
    at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.buildPersistenceContext(AnnotationDeployer.java:4666)
    at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.buildAnnotatedRefs(AnnotationDeployer.java:4039)
    at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.deploy(AnnotationDeployer.java:2961)
    at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.deploy(AnnotationDeployer.java:2000)
    at org.apache.openejb.config.AnnotationDeployer.deploy(AnnotationDeployer.java:384)
    at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:420)
    at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:1037)
    at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1281)
    at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1125)
    at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:133)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5154)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more


Sep 06, 2018 9:28:19 AM sun.reflect.NativeMethodAccessorImpl invoke
GRAVE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:192)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:941)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:681)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:353)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:493)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1421)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1411)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:949)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more


Sep 06, 2018 9:28:19 AM sun.reflect.NativeMethodAccessorImpl invoke
GRAVE: The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
(...)