Hi,
I am using Struts 2 + spring-hibernate + MySQL 5.x to develop an web-application. Using hibernate 3 + annotation for mapping the files.
Hibernate version: 3.2.4SP1
Mapping documents:
ApplicationContext.xml:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<!-- Hibernate SessionFactory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="configurationClass">
<value>org.hibernate.cfg.AnnotationConfiguration</value>
</property>
<property name="configLocation">
<value>WEB-INF/classes/hibernate.cfg.xml</value>
</property>
</bean>
<!-- Transaction manager for a single Hibernate SessionFactory (alternative to JTA) -->
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory"><ref local="sessionFactory"/></property>
</bean>
<!-- ==BUSINESS OBJECT DEFINITIONS == -->
<bean id="adminDao" lazy-init="true"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager"><ref local="transactionManager"/></property>
<property name="target">
<bean class="x.y.dao.AdminDaoImpl">
<property name="sessionFactory"><ref local="sessionFactory"/></property>
</bean>
</property>
<property name="transactionAttributes">
<props>
<prop key="add*">PROPAGATION_REQUIRED</prop>
<prop key="delete*">PROPAGATION_REQUIRED</prop>
<prop key="get*">PROPAGATION_REQUIRED</prop>
<prop key="update*">PROPAGATION_REQUIRED</prop>
<prop key="*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>
</beans>
hibernate.cfg.xml:
Code:
<!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="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">my_db</property>
<property name="connection.username">my_user</property>
<property name="connection.password">my_pass</property>
<property name="dbcp.maxActive">4</property>
<property name="dbcp.maxIdle">2</property>
<property name="dbcp.maxWait">60000</property>
<property name="dbcp.whenExhaustedAction">0</property>
<property name="dbcp.ps.maxActive">30</property>
<property name="dbcp.ps.maxIdle">15</property>
<property name="dbcp.ps.maxWait">60000</property>
<property name="dbcp.ps.whenExhaustedAction">0</property>
<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">20</property>
<property name="hibernate.c3p0.timeout">300</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>
<property name="use_outer_join">true</property>
<property name="show_sql">true</property>
<property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<mapping class="x.y.db.AnsvPersonalObj"/>
<mapping class="x.y.db.Objekt"/>
</session-factory>
</hibernate-configuration>
I have a entity class like this:
AnsvPersonalObj.java
Code:
@Entity
@Table(name = "ansv_personal_obj")
public class AnsvPersonalObj implements Serializable {
@Id
@Column(name = "id", nullable = false)
private long id;
@JoinColumn(name = "objekt_id", referencedColumnName = "prim")
@ManyToOne
private Objekt objekt;
... ...
}
And i need to save a list of elements of this class in one transaction. So in my AdminDaoImpl class I wrote:
AdminDaoImpl.java:
Code:
public void addAnsvPersonalObj(List apObjList) {
Hibernate Template ht = this.getHibernateTemple();
for (int i = 0; i < apObjList.size(); i++) {
ht.save(apObjList.get(i));
}
}
While saveing more than one element at a time, I'm getting the following error:
Code:
javax.servlet.ServletException: a different object with the same identifier value was already associated with the session: [x.y.db.AnsvPersonalObj#0]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [x.y.db.AnsvPersonalObj#0]
The problem I have traced so far is, when one object is saved, it's id is still set to '0'. From the doc, after saving the object, the 'id' should be the set with the saved id from the database. As a result of this bug (!!!), when it tries to save the next object, the id clashes with the previous one (both of them has '0' in id, one saved object and other unsaved). By-the-way, according to the annotation doc, the unsaved-value is automatically set to '0', and Hibernate will know that this object is a new one from id '0'.
At this point, i want to add, I'm using MySQL 5.x, InnoDB and auto-increment for id generation.
The id generation works fine when only one object is saved. It is saved with a incremented value in the database, but the returned value still remains '0', so does the id of the saved object.
Can anyone please help me?
~ Arif
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