Hibernate session is closed using Entity manager

I am developing a part of a software which has two modules(mail and web-service).But I have some confusion in my code which I think that I am doing in wrong way/ in bad way / in difficult ways. Could somebody help me to overcome these? Th problem is hibernate is closing the session.

Here is my pom structure

 -- root
    -- mail
    -- web-service

Point to be noted that my spring bootstrapping,appContext.xml,persistence context are all managed my web-service module and I am using mail module as dependency jar in my web-service module.

My,appContext.xml is like this,

<context:component-scan base-package="com.it.ese.orbitws,com.it.ese.orbitmail" />

<context:annotation-config />
<tx:annotation-driven />


<!-- enables interpretation of the @PersistenceUnit/@PersistenceContext annotations providing convenient
 access to EntityManagerFactory/EntityManager --&g开发者_运维知识库t;
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>


 <bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
    <property name="url" value="jdbc:sqlserver://localhost:1433;database=ORBIT_RC" />
    <property name="username" value="sa" />
    <property name="password" value="sa" />
</bean>

<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
            <property name="databasePlatform" value="org.hibernate.dialect.SQLServerDialect" />
            <property name="showSql" value="true" />
        </bean>
    </property>
    <property name="dataSource" ref="dataSource" />
</bean>


 <bean id="transactionManager"
    class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory"
              ref="entityManagerFactory" />
        <qualifier value="tx"/>
  </bean>

I wanted to make mail module as independent as possible. Also the mail configuration comes from database table:

table : "custom":(smtp,global_sender)

So I made my own JavaMailSenderImpl where I override the getHost method like this.I have made this as spring @Component . My confusions are in comments inside the code.

package com.it.ese.mail
@Component 
public class OrbitJavaMailSenderImpl extends JavaMailSenderImpl{


 private EntityManager entityManager;
 private String smtp=null;

 private OrbitJavaMailSenderImpl() {
 }

 // I have used  PersistenceContextType.EXTENDED because without this,it says
 // Hibernate Session is closed.But using EXTENDED is a bad thing?or it's ok?  

 @PersistenceContext (type= PersistenceContextType.EXTENDED)
 public void setEntityManager(EntityManager entityManager) {
     this.entityManager = entityManager;
 }

 //There is no Bean for CUStom TABLE so far in persistence.xml.Should I do that too?

 @Transactional(readOnly=true)
 public String getSMTPAddress() {
    String host="mail.esolutionss-europe.com";
    try{
        host= this.entityManager.createNativeQuery("SELECT smtp FROM CUSTOM")
                .getSingleResult().toString();
    }catch(Exception e){
        System.out.println("error getting host:"+e.toString());

    }

    return host;
}

}

In the web service module I have a service NotificationService where I am injecting spring mail service.

package com.it.ese.ws.service 
public class NotificationService implements INotificationService {

private EntityManager entityManager;
private String sender=null;

final static Logger logger = Logger.getLogger(NotificationService.class);

@PersistenceContext (type= PersistenceContextType.EXTENDED)
public void setEntityManager(EntityManager entityManager) {
    this.entityManager = entityManager;
}


//Also here if I don't use EXTENTED persistence context,it gives me error as hibernate session is closed.

@Transactional(readOnly=true)
public String getGlobalSender() {
    String sender="a1@xxx.com";
    try{
        sender= entityManager.createNativeQuery("SELECT Global_email FROM CUSTOM")
                .getSingleResult().toString();
    }catch(Exception e){

    }
    return sender;
} /*other methods*/ }

Why my EntityManager is getting closed? Is this Container managed ? what caused the closed sesesion?

Don't use PersistenceContextType.EXTENDED (unless you know very well what you are doing). See here for a detailed explanation.

I found my solution. I made a mistake. what I did is I had a method like

public String getX(){
   return getY()
}

and from getX I call getY which has @Transactional where I actually using Entity Manager. The problem was I did not use @Transactional so it was saying session is closed. Now I did like,

@Transactional 
public String getX(){  //getX() is just a wrapper for some reason :)
  return getY(); 
} 

Now its all smooth. But was it the valid reason or anything else?