java - org.hibernate.ObjectNotFoundException: No row with the given identifier exists, but it DOES

Question

I've got a hibernate problem that I can't fix.

The setup: Java EE, web app, Hibernate 3.2, Tomcat 6, Struts 2.

Basically, I persist an object with my server logic (a struts action), then try and pull that data out for the next page and display it.

I check the database after I save the object, and sure enough, I can see the row there with all the data.

But when I try and retrieve it I get this:

org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [msc.model.Picture#73]

To make things even muddier, when I restart Tomcat and try and access the same object, I don't get the error - Hibernate finds the row just fine.

Hibernate will also be able to see the row if I do some other operations - maybe add a row here and there to the database, not even on the same table.

From all this I suspect a Hibernate bug, but I'm a Hibernate newbie so I am probably wrong. Please help! I've googled and googled to no avail.

Here is my Hibernate config:

<?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.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/msc</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">-------</property>
        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">80</property>
        <property name="current_session_context_class">thread</property>
        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>
        <mapping resource="msc/model/Picture.hbm.xml"/>
        <mapping resource="msc/model/Comment.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

Here are my two mapping files:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="msc.model.Picture" table="PICTURE">
    <id column="PICTURE_ID" name="id">
      <generator class="native"/>
    </id>
    <property name="story"/>
    <property name="email"/>
    <property name="category"/>
    <property name="state"/>
    <property name="ratings"/>
    <property name="views"/>
    <property name="timestamp"/>
    <property name="title"/>
    <property lazy="true" name="image" type="blob">
      <column name="IMAGE"/>
    </property>
    <property lazy="true" name="refinedImage" type="blob">
      <column name="REFINEDIMAGE"/>
    </property>
    <property lazy="true" name="thumbnail" type="blob">
      <column name="THUMBNAIL"/>
    </property>
    <bag cascade="save-update" lazy="true" name="comments" table="COMMENT">
      <key column="PICTURE"/>
      <one-to-many class="msc.model.Comment"/>
    </bag>
  </class>
</hibernate-mapping>

and

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="msc.model.User" table="USER">
    <id column="USER_ID" name="id">
      <generator class="native"/>
    </id>
    <property name="username"/>
    <property name="email"/>
    <bag cascade="save-update" lazy="true" name="pictures" table="PICTURE">
      <key column="USER"/>
      <one-to-many class="msc.model.Picture"/>
    </bag>
    <bag cascade="save-update" lazy="true" name="comments" table="COMMENT">
      <key column="USER"/>
      <one-to-many class="msc.model.Comment"/>
    </bag>
  </class>
</hibernate-mapping>

Please let me know if you need more info, I'm happy to oblige.

(note: this is not a duplicate of this question, the scenario is not the same "No row with the given identifier exists" although it DOES exist)

EDIT: as requested, posting Java code:

Code to save object

Session hib_ses = HibernateUtil.getSessionFactory().getCurrentSession();

hib_ses.beginTransaction();

hib_ses.save(user);

hib_ses.getTransaction().commit(); 

Code to display data (an image in this case)

public class ImageAction extends ActionSupport implements ServletResponseAware, SessionAware {

    private HttpServletResponse response;
    Map session;
    private Long id;
    private int thumbnail;
    private InputStream inputStream;

    @Override
    public String execute() throws Exception {
        response.setContentType("image/jpeg");
        Session hib_session = HibernateUtil.getSessionFactory().getCurrentSession();
        hib_session.beginTransaction();

        //what is the ID now?
        Picture pic = (Picture) hib_session.load(Picture.class, getId());

        if (thumbnail == 1) {
            inputStream = (ByteArrayInputStream) pic.getThumbnail().getBinaryStream();
        } else {
            inputStream = (ByteArrayInputStream) pic.getRefinedImage().getBinaryStream();
        }

        hib_session.close();
        return SUCCESS;
    }

Answer 1

This happens because you have inserted something which is meant to be a foreign key but do not reference anything. Check out you database whether that key exist or not(even though it is in database in other tables).