Question

I’m trying to learn Spring+Hibernate and I started using Lazy loading with Hibernate. To achieve this I need to utilize OpenSessionInViewFilter.

I think the configuration is allright, but I’m pasting it below.

When I try to lazily load some @OneToMany collection I got:

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: lessonScheduler.model.User.applicationses, no session or session was closed

But in log of Hibernate it seems to be all right. The session is opened and the first level is loaded without problems (ends at time 16:43:33,122).

But when I try to lazily load the referenced object I got the Exception mentioned above.

From the log I can see there is a new open session, but then it crashed. I have no idea why…

INFO: 16:43:32,439 DEBUG OpenSessionInViewFilter:239 – Using SessionFactory 'sessionFactory1' for OpenSessionInViewFilter
INFO: 16:43:32,439 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'sessionFactory1'
INFO: 16:43:32,439 DEBUG OpenSessionInViewFilter:181 – Opening single Hibernate Session in OpenSessionInViewFilter
INFO: 16:43:32,439 DEBUG SessionFactoryUtils:316 – Opening Hibernate Session
INFO: 16:43:32,439 DEBUG SessionImpl:220 – opened session at timestamp: 13215446124
INFO: 16:43:32,470 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'userController'
INFO: 16:43:32,548 DEBUG AbstractBatcher:366 – about to open PreparedStatement (open PreparedStatements: 0, globally: 0)
INFO: 16:43:32,548 DEBUG ConnectionManager:421 – opening JDBC connection
INFO: 16:43:32,548 DEBUG DriverManagerDataSource:162 – Creating new JDBC DriverManager Connection to [jdbc:mysql://webdev.felk.cvut.cz:3306/koukavoj]
INFO: 16:43:32,845 DEBUG SQL:401 – select this_.id as id3_0_, this_.firstName as firstName3_0_, this_.lastName as lastName3_0_, this_.login as login3_0_, this_.mail as mail3_0_, this_.password as password3_0_, this_.tel as tel3_0_ from koukavoj.user this_ where this_.id=? limit ?
INFO: Hibernate: select this_.id as id3_0_, this_.firstName as firstName3_0_, this_.lastName as lastName3_0_, this_.login as login3_0_, this_.mail as mail3_0_, this_.password as password3_0_, this_.tel as tel3_0_ from koukavoj.user this_ where this_.id=? limit ?
INFO: 16:43:32,987 DEBUG AbstractBatcher:382 – about to open ResultSet (open ResultSets: 0, globally: 0)
INFO: 16:43:33,002 DEBUG Loader:1173 – result row: EntityKey[lessonScheduler.model.User#1]
INFO: 16:43:33,025 DEBUG AbstractBatcher:389 – about to close ResultSet (open ResultSets: 1, globally: 1)
INFO: 16:43:33,025 DEBUG AbstractBatcher:374 – about to close PreparedStatement (open PreparedStatements: 1, globally: 1)
INFO: 16:43:33,040 DEBUG TwoPhaseLoad:107 – resolving associations for [lessonScheduler.model.User#1]
INFO: 16:43:33,078 DEBUG TwoPhaseLoad:206 – done materializing entity [lessonScheduler.model.User#1]
INFO: 16:43:33,079 DEBUG StatefulPersistenceContext:790 – initializing non-lazy collections
INFO: 16:43:33,080 DEBUG ConnectionManager:302 – transaction completed on session with on_close connection release mode; be sure to close the session to release JDBC resources!
INFO: 16:43:33,115 DEBUG OpenSessionInViewFilter:207 – Closing single Hibernate Session in OpenSessionInViewFilter
INFO: 16:43:33,116 DEBUG SessionFactoryUtils:789 – Closing Hibernate Session
INFO: 16:43:33,117 DEBUG ConnectionManager:441 – releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
INFO: 16:43:33,122 DEBUG ConnectionManager:302 – transaction completed on session with on_close connection release mode; be sure to close the session to release JDBC resources!
INFO: 16:44:42,721 DEBUG OpenSessionInViewFilter:239 – Using SessionFactory 'sessionFactory1' for OpenSessionInViewFilter
INFO: 16:44:42,722 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'sessionFactory1'
INFO: 16:44:42,723 DEBUG OpenSessionInViewFilter:181 – Opening single Hibernate Session in OpenSessionInViewFilter
INFO: 16:44:42,723 DEBUG SessionFactoryUtils:316 – Opening Hibernate Session
INFO: 16:44:42,724 DEBUG SessionImpl:220 – opened session at timestamp: 13215446827
INFO: 16:44:42,735 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'userController'
INFO: 16:44:42,737 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'userController'
INFO: 16:44:42,738 DEBUG DefaultListableBeanFactory:242 – Returning cached instance of singleton bean 'userController'
INFO: 16:44:42,744 ERROR LazyInitializationException:19 – failed to lazily initialize a collection of role: lessonScheduler.model.User.applicationses, no session or session was closed
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: lessonScheduler.model.User.applicationses, no session or session was closed

Web.xml looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <context-param>
        <param-name>javax.faces.DEFAULT_SUFFIX</param-name>
        <param-value>.xhtml</param-value>
    </context-param>
    <listener>
        <listener-class>com.sun.faces.config.ConfigureListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

  <filter>
    <filter-name>hibernateFilter</filter-name>
    <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
    <init-param>
      <param-name>sessionFactoryBeanName</param-name>
      <param-value>sessionFactory1</param-value>
    </init-param>
    <init-param>
      <param-name>singleSession</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>

    <filter-mapping>
        <filter-name>hibernateFilter</filter-name>
        <url-pattern>*.xhtml</url-pattern>
    </filter-mapping>

    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.xhtml</url-pattern>
    </servlet-mapping>
    <welcome-file-list>
        <welcome-file>index.xhtml</welcome-file>
    </welcome-file-list>
</web-app>

Please, if somebody see something strange in the log or config, I will appreciate any help.

Thanks in advance

Answer 1

The entity was loaded at 16:43:32

INFO: 16:43:32,845 DEBUG SQL:401 – select this_.id as id3_0_, this_.firstName as firstName3_0_, this_.lastName as lastName3_0_, this_.login as login3_0_, this_.mail as mail3_0_, this_.password as password3_0_, this_.tel as tel3_0_ from koukavoj.user this_ where this_.id=? limit ?

The session in which it was loaded was closed at 16:43:33:

INFO: 16:43:33,115 DEBUG OpenSessionInViewFilter:207 – Closing single Hibernate Session {...}

Another session was opened at 16:44:42:

INFO: 16:44:42,723 DEBUG SessionFactoryUtils:316 – Opening Hibernate Session

It was during this second Hibernate session that you have the lazy initialization exception. This makes sense, since the Hibernate session attached to the object you loaded was closed when the first Hibernate session was committed back at 16:43:33.

INFO: 16:44:42,744 ERROR LazyInitializationException:19 – failed to lazily initialize a collection of role: lessonScheduler.model.User.applicationses, no session or session was closed

Since I can’t see your code, I’m going to have to guess that you held on to the object’s reference after it was committed, either in a field on a controller in session or application scope, or possibly in the HTTP session.

You should either preload the data you need when you initially load it from the database (by calling the lazy getter when the object is initially loaded, before that first session is closed) OR you should store only the KEY in the field/HTTP session, and reload the object in the subsequent request so the object still has a live Hibernate session associated with it when you call the lazy getter.