Strange java.lang.NoClassDefFoundError

jjari · **Joined:** Mon Dec 29, 2003 10:45 am **Posts:** 12

It looks like a hard road getting Hibernate work, but I'm getting closer. Stdout below clearly tells me that Hibernate engine is up and running, but I still get an NoClassDefFoundError with no classname or anything to point me in the right direction. Exception is thrown at MenuItems' row Session session = HibernateUtil.currentSession();. After that the program enters HibernateUtils static-block but the first row throws the exception. This is a long post, I know, but I am stuck:)

thanks,
Jari

HibernateUtil:

Code:

public class HibernateUtil {
    private static final SessionFactory sessionFactory;

    static {
        try {
            sessionFactory = new Configuration().configure(HibernateUtil.
            class.getClassLoader().getResource("hibernate.cfg.xml")).buildSessionFactory();
        } catch (HibernateException ex) {
            throw new RuntimeException("Exception building SessionFactory: " + ex.getMessage(), ex);
        }
    }

    public static final ThreadLocal session = new ThreadLocal();

    public static Session currentSession() throws HibernateException {
        Session s = (Session) session.get();
        // Open a new Session, if this Thread has none yet
        if (s == null) {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }

    public static void closeSession() throws HibernateException {
        Session s = (Session) session.get();
        session.set(null);
        if (s != null)
            s.close();
    }
}

MenuItems:

Code:

public class MenuItems {

    private SessionFactory sessions;

    public Materialclass[] getMaterialclasses() throws Exception {
        try {
            // the row below causes the exception          
            Session session = HibernateUtil.currentSession();
            Materialclass[] classes;
            Transaction tx= session.beginTransaction();

            List list = session.find("from Materialclass matClass order by matClass.definition");
            tx.commit();
            System.out.println("lista: " + list.size());
            classes = (Materialclass[]) list.toArray();
            return classes;
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
            ex.printStackTrace();
            return null;
        } finally {
            try {
               HibernateUtil.closeSession();
            } catch (HibernateException e) {
                System.out.println(e.getMessage());
            }
        }
    }
}

Exception:

Code:

2003-12-31 13:11:05 StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
java.lang.NoClassDefFoundError
   at emove2.hibernate.MenuItems.getMaterialclasses(MenuItems.java:34)
   at emove2.struts.action.MenuAction.initReceiverMenu(MenuAction.java:29)
   at emove2.struts.action.MenuAction.execute(MenuAction.java:18)
   at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
   at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
   at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
   at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:284)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:204)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
   at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:564)
   at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:245)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:199)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
   at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:594)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
   at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:564)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:195)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
   at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:164)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
   at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:564)
   at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:156)
   at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
   at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:564)
   at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:972)
   at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:211)
   at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:805)
   at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:696)
   at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:605)
   at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:677)
   at java.lang.Thread.run(Unknown Source)

Stdout:

Code:

11:03,453  INFO Environment:432 - Hibernate 2.1.1
11:03,468  INFO Environment:461 - hibernate.properties not found
11:03,468  INFO Environment:481 - using CGLIB reflection optimizer
11:03,484  INFO Configuration:858 - configuring from url: file:/E:/Apache/Tomcat50/work/Catalina/localhost/emove2/WEB-INF/classes/hibernate.cfg.xml
11:03,609 DEBUG DTDEntityResolver:20 - trying to locate http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd in classpath under net/sf/hibernate/
11:03,812 DEBUG DTDEntityResolver:29 - found http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd in classpath
11:03,890 DEBUG Configuration:801 - connection.datasource=java:comp/env/jdbc/emove2DS
11:03,906 DEBUG Configuration:801 - show_sql=false
11:03,906 DEBUG Configuration:801 - use_outer_join=true
11:03,906 DEBUG Configuration:801 - transaction.factory_class=net.sf.hibernate.transaction.JTATransactionFactory
11:03,906 DEBUG Configuration:801 - dialect=net.sf.hibernate.dialect.Oracle9Dialect
11:03,906 DEBUG Configuration:952 - null<-org.dom4j.tree.DefaultAttribute@1759d12 [Attribute: name resource value "hibernate.hbm.xml"]
11:03,906  INFO Configuration:300 - Mapping resource: hibernate.hbm.xml
11:03,921 DEBUG DTDEntityResolver:20 - trying to locate http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd in classpath under net/sf/hibernate/
11:03,921 DEBUG DTDEntityResolver:29 - found http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd in classpath
11:04,093  INFO Binder:225 - Mapping class: emove2.hibernate.model.Materialclass -> EMOVE_CODE_MATERIALCLASS
11:04,234 DEBUG Binder:449 - Mapped property: uid -> uid, type: integer
11:04,281 DEBUG Binder:449 - Mapped property: codeGroup -> codeGroup, type: string
11:04,281 DEBUG Binder:449 - Mapped property: definition -> definition, type: string
11:04,281 DEBUG Binder:449 - Mapped property: materialclass -> materialclass, type: big_decimal
11:04,281  INFO Configuration:998 - Configured SessionFactory: null
11:04,281 DEBUG Configuration:999 - properties: { lots of properties...}
11:04,546  INFO Configuration:584 - processing one-to-many association mappings
11:04,546  INFO Configuration:593 - processing one-to-one association property references
11:04,546  INFO Configuration:618 - processing foreign key constraints
11:04,593  INFO Dialect:82 - Using dialect: net.sf.hibernate.dialect.Oracle9Dialect
11:04,593  INFO SettingsFactory:62 - Use outer join fetching: true
11:04,625  INFO NamingHelper:26 - JNDI InitialContext properties:{}
11:04,656  INFO DatasourceConnectionProvider:51 - Using datasource: java:comp/env/jdbc/emove2DS
11:04,671  INFO TransactionFactoryFactory:31 - Transaction strategy: net.sf.hibernate.transaction.JTATransactionFactory
11:04,671  INFO NamingHelper:26 - JNDI InitialContext properties:{}
11:04,687  INFO TransactionManagerLookupFactory:33 - No TransactionManagerLookup configured (in JTA environment, use of process level read-write cache is not recommended)
11:04,687  INFO TransactionManagerLookupFactory:33 - No TransactionManagerLookup configured (in JTA environment, use of process level read-write cache is not recommended)
AbandonedObjectPool is used (org.apache.commons.dbcp.AbandonedObjectPool@694f12)
   LogAbandoned: false
   RemoveAbandoned: true
   RemoveAbandonedTimeout: 30
11:05,312  INFO SettingsFactory:89 - Use scrollable result sets: true
11:05,312  INFO SettingsFactory:90 - JDBC 2 max batch size: 15
11:05,312  INFO SettingsFactory:99 - Query language substitutions: {}
11:05,312  INFO SettingsFactory:110 - cache provider: net.sf.ehcache.hibernate.Provider

michael · **Posted:** Wed Dec 31, 2003 7:49 am

I think you are still missing required hibernate jars. Please check the readme file in the lib directory and check if you have all required jars in the classpath. This is hard to tell without info which class is not found.

jjari · **Joined:** Mon Dec 29, 2003 10:45 am **Posts:** 12

gloeglm wrote:

I think you are still missing required hibernate jars. Please check the readme file in the lib directory and check if you have all required jars in the classpath.

They are all there in the war-file, all that say required, standalone or not.

gloeglm wrote:

This is hard to tell without info which class is not found.

Believe me, I know...

Jari

emmanuel · **Posted:** Wed Dec 31, 2003 8:30 am

Try to move you static block into a plain non static method (use the singleton pattern with lazy initialization). There is probably a classloader problem.

Code:

public static MyClass getInstance() {
  if (_instance == null) {
    _instance = new MyClass();
  }
  return _instance;
}

public MyClass() {
  //init Hibernate
}
}

jjari · **Joined:** Mon Dec 29, 2003 10:45 am **Posts:** 12

Thanks, that helped, I was missing (optional?) ehcache.jar. Now I have some new exceptions but I'll try to figure them out by myself first.

Happy New Year,
Jari

baliukas · **Posted:** Wed Dec 31, 2003 9:14 am

The class name can be "HibernateUtil".

If this code fails:

static {
try {
sessionFactory = new Configuration().configure(HibernateUtil.
class.getClassLoader().getResource("hibernate.cfg.xml")).buildSessionFactory();
} catch (HibernateException ex) {
throw new RuntimeException("Exception building SessionFactory: " + ex.getMessage(), ex);
}
}

it will produce "ExceptionInInitializerError" caused by "RuntimeException" caused by "HibernateException".
It can be thrown only once, next time JVM will not try to call <clinit>, it will mark class as dead and will thow CNF.
It must be better to configure hibernate in Servlet.init(), it will help to find problems faster, Servlet.destroy() can be used to close pool too.