[jboss-user] [EJB3] - EJB java.lang.NoClassDefFoundError: javax/persistence/EntityManager

marco squarcini [https://community.jboss.org/people/squarcio] created the discussion "EJB java.lang.NoClassDefFoundError: javax/persistence/EntityManager" To view the discussion, visit: https://community.jboss.org/message/826760#826760 -------------------------------------------------------------- Hello to all, I'm new to javaEE and JBoss AS and i'm trying to learn developing EJB applications but i have a problem i don't know how to solve. I use NetBeans 7.3 and JBoss AS 7.1.1. I have been created an EJB 3.1 module with an entity bean and a session bean with remote interface that performs the database operations using the entity bean. After i have been created a java application to access the EJB module: 1. inside the library of the project i put the jboss-client.jar and the EJB module.jar files 2. i have been created a config package with the jboss-ejb-client.properties file 3. i lookup the bean with the method : public static ControllerPrenotazioniRemote lookupRemoteControllerPrenotazioni() throws NamingException {         final Hashtable jndiProperties = new Hashtable();         jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");         final Context context = new InitialContext(jndiProperties);         final String appName = "";         final String moduleName = "EJBModule1";         final String distinctName = "";         final String beanName = ControllerPrenotazioni.class.getSimpleName();         final String viewClassName = ControllerPrenotazioniRemote.class.getName();         System.out.println("Looking EJB via JNDI ");         System.out.println("ejb:" + appName + "/" + moduleName + "/" + distinctName + "/" + beanName + "!" + viewClassName);         return (ControllerPrenotazioniRemote) context.lookup("ejb:/EJBModule1/ControllerPrenotazioni!"                 + ControllerPrenotazioniRemote.class.getName() + "?stateful");     } I deploy the EJB module less problems,but when i try to run the java application i see thi error in the output tab of NetBeans: Exception in thread "main" java.lang.NoClassDefFoundError: javax/persistence/EntityManager     at controllers.ControllerPrenotazioni.trovaPrenotazione(ControllerPrenotazioni.java:133)     at principale.Main.main(Main.java:22) Caused by: java.lang.ClassNotFoundException: javax.persistence.EntityManager     at java.net.URLClassLoader$1.run(URLClassLoader.java:366)     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)     at java.security.AccessController.doPrivileged(Native Method)     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)     at java.lang.ClassLoader.loadClass(ClassLoader.java:424)     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)     at java.lang.ClassLoader.loadClass(ClassLoader.java:357)     ... 2 more Java Result: 1 I do not know where I'm wrong!Someone can help me to solve this problem? Thank you to all in advance.... -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/826760#826760] Start a new discussion in EJB3 at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]