hibernate throws nullpointerexception

[oll3i]

Thank you for the last post :) now another problem

when i flush the session hibernate throws nullpointerexception

my code looks as follows

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
 
public class FirstExample {
  public static void main(String[] args) {
    Session session = null;
 
    try{
      // W tym kroku odczytamy plik hibernate.cfg.xml i przygotujemy Hibernate do użycia     
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        session = sessionFactory.openSession();
 
        //Stworzenie nowego obiektu Contact i ustawienie jego atrybutów
         System.out.println("Inserting Record");
        Contact contact = new Contact();
        contact.setId(3);
        contact.setFirstName("Jan");
        contact.setLastName("Kowalski");
        contact.setEmail("[e-mail]");
        //zapisanie zmian dokonanych od ostatniego zapisu
        session.save(contact);
        System.out.println("Done");
    }catch(Exception e){
      System.out.println(e.getMessage());
    }finally{
      // wymuszenie wysłania "oczekujących" operacji do bazy danych
      session.flush();
      // zamknięcie sesji
      session.close();
      }
  }
}
 

[oll3i]

my hibernate.cfg.xml file

<?xml version='1.0' encoding='utf-8'?>
        <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibeornate/Hibernate Configuration DTD//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
        <hibernate-configuration>
    <session-factory>
              <property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property>
              <property name="hibernate.connection.url">jdbc:hsqldb:hsql://localhost:1701</property>
              <property name="hibernate.connection.username">sa</property>
              <property name="hibernate.connection.password"></property>
              <property name="hibernate.connection.pool_size">1</property>
              <property name="show_sql">true</property>
              <property name="dialect">org.hibernate.dialect.HSQLDialect</property>
              <property name="hibernate.hbm2ddl.auto">update</property>
              <!-- Mapping files -->
              <mapping resource="Contact.hbm.xml"/>
    </session-factory>
        </hibernate-configuration>
 

[oll3i]

i changed my hibernate.cfg.xml to

<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 
<hibernate-configuration>
    <session-factory>
              <property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property>
              <property name="hibernate.connection.url">jdbc:hsqldb:hsql://localhost:1701</property>
              <property name="hibernate.connection.username">sa</property>
              <property name="hibernate.connection.password"></property>
              <property name="hibernate.connection.pool_size">1</property>
              <property name="show_sql">true</property>
              <property name="dialect">org.hibernate.dialect.HSQLDialect</property>
              <property name="hibernate.hbm2ddl.auto">update</property>
              <!-- Mapping files -->
              <mapping resource="Contact.hbm.xml"/>
    </session-factory>
        </hibernate-configuration>
 

[JosAH]

Isn't there a stacktrace and line number available somewhere?

kind regards,

Jos

[oll3i]

i added to my code

 } catch (Throwable e) {
        System.err.println("Error in creating SessionFactory object." 
            + e.getMessage());
        throw new ExceptionInInitializerError(e);
    }
 

and now i get

Error in creating SessionFactory object.org/dom4j/DocumentException
Exception in thread "main" java.lang.NullPointerException
at FirstExample.main(FirstExample.java:30)

[JosAH]

i added to my code

 } catch (Throwable e) {
        System.err.println("Error in creating SessionFactory object." 
            + e.getMessage());
        throw new ExceptionInInitializerError(e);
    }
 

and now i get

Error in creating SessionFactory object.org/dom4j/DocumentException
Exception in thread "main" java.lang.NullPointerException
at FirstExample.main(FirstExample.java:30)

According to your code in your OP that should be 'session.close()' which I don't
believe. Please include the line(s) indicated by the line number in the exception.
You can't leave us guessing like that.

kind regards,

Jos

[oll3i]

sorry

the code is

package project1;
 
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
 
 
 
public class FirstExample {
  public static void main(String[] args) {
    Session session = null;
 
    try{
      // W tym kroku odczytamy plik hibernate.cfg.xml i przygotujemy Hibernate do użycia     
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        session = sessionFactory.openSession();
 
        //Stworzenie nowego obiektu Contact i ustawienie jego atrybutów
         System.out.println("Inserting Record");
        Contact contact = new Contact();
        contact.setId(3);
        contact.setFirstName("Jan");
        contact.setLastName("Kowalski");
        contact.setEmail("[e-mail]");
        //zapisanie zmian dokonanych od ostatniego zapisu
        session.save(contact);
        System.out.println("Done");
    } catch (Throwable e) {
        System.err.println("Error in creating SessionFactory object." 
            + e.getMessage());
        throw new ExceptionInInitializerError(e);
    }finally{
      // wymuszenie wysłania "oczekujących" operacji do bazy danych
      session.flush();
      // zamknięcie sesji
      session.close();
      }
  }
}
 

and the error is


Error in creating SessionFactory object.org/dom4j/DocumentException
Exception in thread "main" java.lang.NullPointerException
at project1.FirstExample.main(FirstExample.java:34)

so it is session.flush when i comment it, it is session.close that causes the error

maybe there is something wrong with my hibernate.cfg.xml file
seems like a sessionfactory is not created at all

[JosAH]

Yep, that's it and your finally clause is wrong: if there is no session yet you
can't flush() nor close() it. Make that finally clause:

if (session != null) {
   session.flush(); 
   session.close(); 
}
 

... and print out the entire exception stacktrace in your catch clause:

e.printStackTrace();
 

... and see what happened instead of hiding it.

kind regards,

Jos

[oll3i]

there You go :)


Error in creating SessionFactory object.org/dom4j/DocumentException
Exception in thread "main" java.lang.ExceptionInInitializerError
at project1.FirstExample.main(FirstExample.java:31)
Caused by: java.lang.NoClassDefFoundError: org/dom4j/DocumentException
at project1.FirstExample.main(FirstExample.java:15)
Caused by: java.lang.ClassNotFoundException: org.dom4j.DocumentException
at java.net.URLClassLoader$1.run(URLClassLoader.java: 200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 52)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:320)
... 1 more

[oll3i]

i added more jars and now i get hihi i just can not wait gotta do something

2008-10-17 21:22:18 org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.2.5
2008-10-17 21:22:18 org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
2008-10-17 21:22:19 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: Bytecode provider name : cglib
2008-10-17 21:22:19 org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
2008-10-17 21:22:19 org.hibernate.cfg.Configuration configure
INFO: configuring from resource: /hibernate.cfg.xml
2008-10-17 21:22:19 org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: Configuration resource: /hibernate.cfg.xml
Error in creating SessionFactory object./hibernate.cfg.xml not found
Exception in thread "main" java.lang.ExceptionInInitializerError
at project1.FirstExample.main(FirstExample.java:31)
Caused by: org.hibernate.HibernateException: /hibernate.cfg.xml not found
at org.hibernate.util.ConfigHelper.getResourceAsStrea m(ConfigHelper.java:147)
at org.hibernate.cfg.Configuration.getConfigurationIn putStream(Configuration.java:1405)
at org.hibernate.cfg.Configuration.configure(Configur ation.java:1427)
at org.hibernate.cfg.Configuration.configure(Configur ation.java:1414)
at project1.FirstExample.main(FirstExample.java:15)

[oll3i]

and another one now it sees the files

2008-10-17 21:34:40 org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.2.5
2008-10-17 21:34:41 org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
2008-10-17 21:34:41 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: Bytecode provider name : cglib
2008-10-17 21:34:41 org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
2008-10-17 21:34:41 org.hibernate.cfg.Configuration configure
INFO: configuring from resource: /hibernate.cfg.xml
2008-10-17 21:34:41 org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: Configuration resource: /hibernate.cfg.xml
2008-10-17 21:34:43 org.hibernate.cfg.Configuration addResource
INFO: Reading mappings from resource : Contact.hbm.xml
Error in creating SessionFactory object.org/apache/commons/collections/SequencedHashMap
Exception in thread "main" java.lang.ExceptionInInitializerError
at project1.FirstExample.main(FirstExample.java:31)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/collections/SequencedHashMap
at org.hibernate.mapping.Table.<init>(Table.java:33)
at org.hibernate.cfg.Mappings.addTable(Mappings.java: 165)
at org.hibernate.cfg.HbmBinder.bindRootPersistentClas sCommonValues(HbmBinder.java:290)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinde r.java:273)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.jav a:144)
at org.hibernate.cfg.Configuration.add(Configuration. java:669)
at org.hibernate.cfg.Configuration.addInputStream(Con figuration.java:504)
at org.hibernate.cfg.Configuration.addResource(Config uration.java:566)
at org.hibernate.cfg.Configuration.parseMappingElemen t(Configuration.java:1587)
at org.hibernate.cfg.Configuration.parseSessionFactor y(Configuration.java:1555)
at org.hibernate.cfg.Configuration.doConfigure(Config uration.java:1534)
at org.hibernate.cfg.Configuration.doConfigure(Config uration.java:1508)
at org.hibernate.cfg.Configuration.configure(Configur ation.java:1428)
at org.hibernate.cfg.Configuration.configure(Configur ation.java:1414)
at project1.FirstExample.main(FirstExample.java:15)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.SequencedHashMap
at java.net.URLClassLoader$1.run(URLClassLoader.java: 200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 52)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:320)
... 15 more

[JosAH]

Hold on; no need to make this the longest thread ever; now it can't find the class
SequencedHashMap. You have a classpath problem: include all the jars needed
by your application, if you miss one your exception stacktrace will tell you which
class couldn't be found: include it in your classpath until all is fine.

kind regards,

Jos

[oll3i]

sure :) i like adding those jars

[oll3i]

NOW everything almost works except that it doesn't insert the values into the hsql table

[N002213F]

usually when u are inserting a new record you don't specify the object id, by specifying the id you are telling hibernate to update an existing object.

I see you have enabled the option to see the SQL hibernate generates, what is it generating, is it and INSERT or UPDATE?

[deepakcg]

How are you checking if the insert is happening, through sql only or by retrieving the values in some way? If there is insert statement and still not getting the values in table, worth checking the auto commit feature. Something similar to oracle config mentioned here.