NullPointerException in session.flush()

[vinoth subramaniam]

Hi all, i am getting the NullPointerException in my application. Please Help me to solve this.

Here is the hibernate.cfg.xml

  
 
<?xml version='1.0' encoding='utf-8'?>
<!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">
com.microsoft.jdbc.sqlserver.SQLServerDriver
</property>
<property name="hibernate.connection.url">
jdbc:microsoft:sqlserver://localhost:1433;databseName=JT01_LAMDA;selectMethod=cursor
</property>
<property name="hibernate.connection.username">
sa
</property>
<property name="hibernate.connection.password">
Password123
</property>
<property name="dialect">
org.hibernate.dialect.SQLServerDialect
</property>
<property name="show_sql">true</property>
<property name="transaction.factory_class">
org.hibernate.transaction.JDBCTransactionFactory
</property>
<property name="hibernate.cache.provider_class">
org.hibernate.cache.HashtableCacheProvider
</property>
<property name="hibernate.hbm2ddl.auto">update</property>
 
<mapping resource="hibernate\event\Event.hbm.xml" />
 
</session-factory>
 
</hibernate-configuration>
 
  

---------------------------------------------------------------

Here is the contact.hbm.xml

<?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="com.tcs.lamda.POC.hibernate.Contact.java" 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>

--------------------------------------------------------------------

Here is the java file inserting the record to the databse

 
 
1    package com.tcs.lamda.POC.hibernate;
 
2    import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
 
// this is the example to insert the data in to the contact table
 
public class FirstExample {
 
public static void main(String[] args) {
Session session = null;
 
try {
// reading hibernate.cfg.xml and prepare hibernate for use
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
session = sessionFactory.openSession();
 
//Creating 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(3);
contact.setFirstName("vinoth");
contact.setLastName("Subramanian");
contact.setEmail("[e-mail]");
session.save(contact);
System.out.println("Done");

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

 
}
}
 
}  

----------------------------------------------------------------------

And i am getting the following error at the line "session.flush();"

Exception in thread "main" java.lang.NullPointerException
at com.tcs.lamda.POC.hibernate.FirstExample.main(FirstExample.java:33)

Please help me to solve this issue. Please ask if you need any further information.

[Don Solomon]

never used this stuff in my life.

i would put "Contact contact=null" before the try block. then "contact=new Contact()" inside the try block. Contact has gone out of scope in your finally.

[Jaikiran Pai]

Probably your session object never got created in the try block. Your catch block is eating the actual exception:

} catch (Exception e) {
System.out.println(e.getMessage());
}

At the very least, i would do a e.printStackTrace() in the catch block to see the actual error.

And also your finally block can be improved to do a null check:

finally {
        if (session != null) {
  // Actual contact insertion will happen at this step
  session.flush();
  session.close();
         }

 
}