OpenEntityManagerInViewFilter Problems

Question

I have scoured this site among others for answers in getting OpenEntityManagerInViewFilter to work. I have a standard User object that references a roles object with a many to many relationship as a set. When I am try to edit my user from the controller I get the dreaded lazy init exception. For the most part it seems that this should be very trivial to implement by simply adding this to your web.xml:

<filter>
    <filter-name>oemInViewFilter</filter-name>
    <filter-class>
        org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter
    </filter-class>
</filter>

<filter-mapping>
    <filter-name>oemInViewFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

Now to things I have tried without success (these are various suggestions from around the web)

1. Move the above declaration to very top of the web.xml
2. Slap @Transactional around my controller method and/or whole class
3. Obviously switching fetch type to eager works, but defeats my intentions here
4. Playing with where I have my entityManagerFacorty defined
5. Verified that OpenEntityManager is present in the lazy init exception, thus its being fired off

About the only thing that I have read that makes sense to me as why this isn't working is that I am loading two different sessions because of how my persistence layer is set up and the filter is grabbing the wrong one.

Heres the method in my controller where I find a user from the database and causes the lazy init exception because it didn't retrieve roles from the user object.

@RequestMapping(value = "/edit/{id}", method = RequestMethod.GET)
   public String edit(@PathVariable final Integer id, final ModelMap modelMap)
   {
      final User user = userDao.find(id); ******This causes the lazy init exception

      if (user != null)
      {
         modelMap.addAttribute("userInstance", user);
         modelMap.addAttribute("validRoles",  new HashSet<Role>(roleDao.findAll()));
         return "/user/edit";
      }
      return "redirect:/user/list";
   }

Here is my relevant setup:

Web.xml:

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         id="WebApp_ID" version="2.5">

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/board-servlet.xml  *****This file references the file with entityManager declared*****
            /WEB-INF/board-security.xml
        </param-value>
    </context-param>

    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>board</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>board</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.css</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.js</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.jpg</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.png</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.gif</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.ico</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

    <filter>
        <filter-name>oemInViewFilter</filter-name>
        <filter-class>
            org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter
        </filter-class>
    </filter>

    <filter-mapping>
        <filter-name>oemInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <filter>
        <filter-name>sitemesh</filter-name>
        <filter-class>
            com.opensymphony.module.sitemesh.filter.PageFilter
        </filter-class>
    </filter>

    <filter-mapping>
        <filter-name>sitemesh</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

board-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">

  ****This is what pulls in my entityManager  
 <import resource="classpath:persistence-spring-beans.xml"/> 

    <mvc:annotation-driven/>

    <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="100000"/>
    </bean>

    <bean id="messageSource"
          class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basename" value="classpath:message"/>
        <property name="defaultEncoding" value="UTF-8"/>
    </bean>

</beans>

persistence-spring-beans.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">

    <context:annotation-config/>
    <context:component-scan base-package="com.something" use-default-filters="true"/>
    <aop:aspectj-autoproxy proxy-target-class="true"/>

    <tx:annotation-driven transaction-manager="transactionManager"/>

    <bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
        <property name="persistenceUnitName" value="prodPersistenceUnit"/>
        <property name="dataSource" ref="c3p0PostgresDataSource"/>
        <property name="packagesToScan" value="com.something.persistence.dto"/>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
        </property>
    </bean>

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

    <bean id="c3p0PostgresDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="org.postgresql.Driver"/>
        <property name="jdbcUrl" value="jdbc:postgresql://localhost:5432/yellow_hammer"/>
        <property name="user" value="yellow"/>
        <property name="password" value="hammer"/>
        <property name="initialPoolSize" value="3"/>
        <property name="minPoolSize" value="3"/>
        <property name="maxPoolSize" value="50"/>
        <property name="idleConnectionTestPeriod" value="200"/>
        <property name="acquireIncrement" value="1"/>
        <property name="maxStatements" value="0"/>
        <!-- 0 means: statement caching is turned off.  -->
        <property name="numHelperThreads" value="3"/>
        <!-- 3 is default -->
    </bean>
</beans>

Let me know if this isn't enough relevant information.

EDIT UserDao - this extends a GenericDao, I'll post this just below.

@Dao
public class UserDao extends GenericDao<User>
{
   public User findByUsernameAndPassword(final String username, final String password)
   {
      final Query query = entityManager.createQuery("from User user " + "where user.username = :user " + "and user.password = :pass ")
         .setParameter("user", username)
         .setParameter("pass", password);

      return uniqueResult(query);
   }

   public List<User> findByRole(final Role roleIn)
   {
      if (roleIn == null)
      {
         return null;
      }

      final Query query = entityManager.createQuery("select user from User user, Role role where role = :roleParam ").
         setParameter("roleParam", roleIn);

      return query.getResultList();
   }
}

GenericDao

public class GenericDao<T extends BaseDto>
{
   protected Class<T> entityClass;

   @PersistenceContext
   protected EntityManager entityManager;

   public GenericDao()
   {
      final ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();
      this.entityClass = (Class<T>) genericSuperclass.getActualTypeArguments()[0];
   }

   public T find(final Integer id)
   {
      return entityManager.find(entityClass, id);
   }

   public List<T> findAll()
   {
      final Query query = entityManager.createQuery("from " + entityClass.getSimpleName());
      return query.getResultList();
   }

   public T save(final T t)
   {
      if (t != null)
      {
         return t.getId() != null && t.getVersion() != null ? update(t) : create(t);
      }

      return null;
   }

   private T create(final T t)
   {
      entityManager.persist(t);
      return t;
   }

   private T update(final T t)
   {
      return entityManager.merge(t);
   }

   public void delete(T t)
   {
      t = entityManager.merge(t);
      entityManager.remove(t);
   }

   protected T uniqueResult(final Query query)
   {
      final List results = query.getResultList();
      if (results.isEmpty())
      {
         return null;
      }
      else if (results.size() == 1)
      {
         return entityClass.cast(results.get(0));
      }

      // TODO send notification, multiple results found
      return null;
   }
}

Answer 1

But now!!

Let me make a guess: the name of your application is: board?

Correct? then go on and read the remaining answer!

Yes you have two entity manager, and even two identical application contexts (one app context and one web context) -- So you have every bean twice!

What happened is: you have only one (relevant) spring configuration file: 'board-servlet.xml' ('persistence-spring-beans.xml' is included in that file so at least it is one big logical file)

And you create a context from this file twice in the 'web.xml':

first:

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/board-servlet.xml  *****This file references the file with entityManager declared*****
        /WEB-INF/board-security.xml
    </param-value>
</context-param>
...
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

ContextLoaderListener load the application context specified by the files in 'contextConfigLocation' parameter.

second:

<servlet>
    <servlet-name>board</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

Dispatcher Servlet create the web application context, which xml file is:

• named by the init-param 'contextConfigLocation'
• or, if there is no such paramter, it looks for an file named '/WEB-INF/-servlet.xml'

(For more details have a look at the Java Doc of FrameworkServlet)

In your case there is no explicitly named file, so it reads the 'board-servlet.xml' again.

What you need to do is separate them:

• remove the <import resource="classpath:persistence-spring-beans.xml"/> from board-servlet.xml
• change the contextConfigLocation in web.xml that it refers to classpath:persistence-spring-beans.xml and /WEB-INF/board-security.xml direcly
• (not 100% necessary) separate the 'context:component-scan' so that a component scan in board-servlet.xml scan only for @Controller and the component scan in persistence-spring-beans.xml scan for the others (@Service, @Component, @Repository and @Dao)
• last step: please tell me that it works now