Strange Error

[subhashchandra medhiassam]

Hi all,
I am trying to execute a program to insert values into a table named Contact present in mysql. This same program was working about a two weeks back. I did not touch it for the last two weeks. Now when i run it i am getteing the following message:

 Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.0rc1
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Environment <clinit>
INFO: using CGLIB reflection optimizer
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration configure
INFO: configuring from resource: /hibernate.cfg.xml
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: Configuration resource: /hibernate.cfg.xml
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration addResource
INFO: Mapping resource: contact.hbm.xml
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.HbmBinder bindRootPersistentClassCommonValues
INFO: Mapping class: roseindia.tutorial.hibernate.Contact -> CONTACT
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration doConfigure
INFO: Configured SessionFactory: null
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration secondPassCompile
INFO: processing extends queue
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration secondPassCompile
INFO: processing collection mappings
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration secondPassCompile
INFO: processing association property references
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.Configuration secondPassCompile
INFO: processing foreign key constraints
Sep 26, 2008 10:21:49 AM org.hibernate.dialect.Dialect <init>
INFO: Using dialect: org.hibernate.dialect.MySQLDialect
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Maximum outer join fetch depth: 2
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default batch fetch size: 1
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Generate SQL with comments: disabled
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL updates by primary key: disabled
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory
INFO: Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
Sep 26, 2008 10:21:49 AM org.hibernate.hql.ast.ASTQueryTranslatorFactory <init>
INFO: Using ASTQueryTranslatorFactory
Sep 26, 2008 10:21:49 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query language substitutions: {}
Sep 26, 2008 10:21:49 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Using Hibernate built-in connection pool (not for production use!)
Sep 26, 2008 10:21:49 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Hibernate connection pool size: 15
Sep 26, 2008 10:21:49 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: autocommit mode: false
Sep 26, 2008 10:21:49 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost/hibernatetutorial
Sep 26, 2008 10:21:49 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: connection properties: {user=root, password=****}
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch size: 15
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch updates for versioned data: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Scrollable result sets: enabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC3 getGeneratedKeys(): enabled
Sep 26, 2008 10:21:50 AM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory
INFO: Using default transaction strategy (direct JDBC transactions)
Sep 26, 2008 10:21:50 AM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup
INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic flush during beforeCompletion(): disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic session close at end of transaction: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory createCacheProvider
INFO: Cache provider: org.hibernate.cache.EhCacheProvider
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Second-level cache: enabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Optimize cache for minimal puts: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Structured second-level cache entries: enabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query cache: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Echoing all SQL to stdout
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Statistics: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Deleted entity synthetic identifier rollback: disabled
Sep 26, 2008 10:21:50 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default entity-mode: pojo
Sep 26, 2008 10:21:50 AM org.hibernate.impl.SessionFactoryImpl <init>
INFO: building session factory
Sep 26, 2008 10:21:50 AM net.sf.ehcache.config.Configurator configure
WARNING: No configuration found. Configuring ehcache from ehcache-failsafe.xml found in the classpath: jar:file:/C:/EclipseWorkspace/hibernateexample-insert-delete-update/lib/ehcache-1.1.jar!/ehcache-failsafe.xml
Exception in thread "main" java.lang.NullPointerException
at roseindia.tutorial.hibernate.InsertExample.main(InsertExample.java:41)
   

The table Contact which is in MYSQL looks like the following:

Column Type
---------------------------
ID int
FIRSTNAME varchar
LASTNAME varchar
EMAIL varchar


My .hbm.xml file looks like the following:

 <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 
<hibernate-mapping>
  <class name="roseindia.tutorial.hibernate.Contact" table="CONTACT">
   <id name="id" type="long" column="ID" >
   <generator class="assigned"/>
  </id>
 
  <property name="firstName">
     <column name="FIRSTNAME" />
  </property>
  <property name="lastName">
    <column name="LASTNAME"/>
  </property>
  <property name="email">
    <column name="EMAIL"/>
  </property>
 </class>
 
 
</hibernate-mapping>   

The class Contact looks like the following:

  package roseindia.tutorial.hibernate;
 
public class Contact {
private String firstName;
private String lastName;
private String email;
private long id;
 
/**
 * @return Email
 */
public String getEmail() {
return email;
}
 
/**
 * @return First Name
 */
public String getFirstName() {
return firstName;
}
 
/** 
 * @return Last name
 */
public String getLastName() {
return lastName;
}
 
/**
 * @param string Sets the Email
 */
public void setEmail(String string) {
email = string;
}
 
/**
 * @param string Sets the First Name
 */
public void setFirstName(String string) {
firstName = string;
}
 
/**
 * @param string sets the Last Name
 */
public void setLastName(String string) {
lastName = string;
}
 
/**
 * @return ID Returns ID
 */
public long getId() {
return id;
}
 
/**
 * @param l Sets the ID
 */
public void setId(long l) {
id = l;
}
 
}
  

And the class InsertExample.java in which i do the data insertion looks like the following:

 
package roseindia.tutorial.hibernate;
 
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
 

public class InsertExample {
public static void main(String[] args) {
    Session session = null;
 
try{
// This step will read hibernate.cfg.xml and prepare hibernate for use
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
session =sessionFactory.openSession();
Transaction tx = session.beginTransaction();
//Create new instance of Contact and set values in it by reading them from form object
 
System.out.println("Inserting Record");
Contact contact = new Contact();
contact.setId(6);
contact.setFirstName("Subhash");
contact.setLastName("Medhi");
contact.setEmail("[e-mail]");
session.save(contact);
tx.commit();
System.out.println("Done");

}catch(Exception e){
System.out.println(e.getMessage());
}finally{
// Actual contact insertion will happen at this step
session.flush();
session.close();
 
}

}
}
   

What could be the reason for this output?

Kindly help.

Thanks,
Subhash

[Paul Sturrock]

Exception in thread "main" java.lang.NullPointerException
at roseindia.tutorial.hibernate.InsertExample.main(InsertExample.java:41)

What happens on line 41 of InsertExample?

[subhashchandra medhiassam]

That line corresponds to "session.flush();". Anyway, the problem is solved now. Thanks, for your response, Paul.

[Paul Sturrock]

So what was your error? Did the session fail to be created in the first place? Or the SessionFactory configuration fail?

Its a good idea to enclose the session.close() code in a null check to avoid this condition.