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java.lang.Object; cannot be cast to shoppingbasket.Product

I am trying to retrieve a list of products with they're associated offers. After iterating through the result of the query I want to be able to use the getters/setters from the products class but I know it's not working because the query is not returning an instance of Product.
function to grab the products:
public List<Product> getProducts() {
factory = (new Configuration()).configure().buildSessionFactory();
Session session = factory.getCurrentSession();
session.beginTransaction();
List<Product> products = new ArrayList<Product>();
Query query = session.createQuery("from Product p INNER JOIN p.offers");
//The castList is declared and explained at the bottom of listing
List<Product> list = query.list();
Iterator<Product> iter = list.iterator();
while (iter.hasNext()) {
Product product = iter.next();
System.out.println(product);
}
}
Hibernate mapping for Offer:
<hibernate-mapping>
<class name="shoppingbasket.Offer" table="offers">
<id name="offerID" type="integer" access="field">
<column name="OfferID" />
<generator class="assigned" />
</id>
<property name="offerDescription" type="java.lang.String" access="field">
<column name="OfferDescription" length="60" not-null="true"/>
</property>
<property name="shortDescription" type="java.lang.String" access="field">
<column name="ShortDescription" length="10" not-null="false"/>
</property>
<property name="TFTPOTGroup" type="java.lang.Integer" access="field">
<column name="TFTPOTGroup" length="4" not-null="false" default="null"/>
</property>
<property name="discountPercentage" type="java.lang.Double" access="field">
<column name="DiscountPercentage" not-null="false" default="null"/>
</property>
</class>
Hibernate mapping for Product:
<hibernate-mapping>
<class name="shoppingbasket.Product" table="products">
<id name="productID" type="integer" access="field">
<column name="ProductID" />
<generator class="assigned" />
</id>
<property name="offerID" type="java.lang.Integer" access="field">
<column name="OfferID" />
</property>
<property name="productName" type="java.lang.String" access="field">
<column name="ProductName" length="40" not-null="true"/>
</property>
<property name="unitPrice" type="java.math.BigDecimal" access="field">
<column name="UnitPrice"/>
</property>
<one-to-one name="offers" class="shoppingbasket.Offer" />
</class>
Product class:
public class Product implements java.io.Serializable {
private Integer productID;
private Integer offerID;
private String productName;
private BigDecimal unitPrice;
private Offer offer;
public Integer getProductID() {
return productID;
}
public void setProductID(Integer productID) {
this.productID = productID;
}
public Integer getOfferID() {
return this.offerID;
}
public void setOfferID(Integer offerID) {
this.offerID = offerID;
}
public Offer getOffers() {
return offer;
}
public void setOffers(Offer offer) {
this.offer = offer;
}
//more getters/setters
}
Offer class:
public class Offer
{
private Integer offerID;
private String offerDescription;
private String shortDescription;
private Integer TFTPOTGroup;
private Double discountPercentage;
public Integer getOfferID() {
return offerID;
}
public void setOfferID(Integer offerID) {
this.offerID = offerID;
}
//more getters/setters
}
Any help would be hugely appreciated

#Potential Unnecessary Projections Data:
Since you're not specifying SELECT clause in the query and putting explicit joins, hibernate will return 2 objects per row (Product, Offers), wherein Product object might already be populated with the Offer data due to underlying mapping associations.
Try adding select clause to the query and see if it casts correctly
Add SELECT p FROM ... to the query

Hibrernate: Attribute "type" must be declared for element type "column"

I am trying to save to two tables in SQL server using Hibernate:
ORDER and ORDER_ITEM
I get an error:
Attribute "type" must be declared for element type "column".
Initial SessionFactory creation failed.org.hibernate.InvalidMappingException: Unable to read XML.
This produces a NullPointerException
If I understand correctly, this means that when I try to save to the order_item table, the getter for the foreign key is empty, but how would I set it if is designed to 'Autoincrement', I thought that hibernate would handle this in it's transaction.
Below are my POJO's and Hibernate mappings. I have omitted the getters and setters from this copy/paste, but they are present in my actual code
I am also successful in saving just to the ORDER table if I remove the set
Order.java:
public class Order {
public Order(){
super();
}
private int orderId;
private Set<LineItem> items;
private String strPhone;
private String strEmail;
private String strFirstName;
private String strLastName;
private String strParentFirstName;
private String strParentLastName;
private String strOrganizationName;
private String strOrganizationType;
private String strComment;
}
order.hbm.xml:
<hibernate-mapping>
<class name="dbobjects.Order" table="orders">
<id name="orderId" type="integer" column="order_id">
<generator class="increment"/>
</id>
<property name="strPhone" type="string" column="phone_number"/>
<property name="strFirstName" type="string" column="first_name"/>
<property name="strLastName" type="string" column="last_name"/>
<property name="strParentFirstName" type="string" column="parent_first_name"/>
<property name="strParentLastName" type="string" column="parent_last_name"/>
<property name="strOrganizationName" type="string" column="organization_name"/>
<property name="strOrganizationType" type="string" column="organization_type"/>
<property name="strComment" type="string" column="comments"/>
<set name="items" table="order_item" fetch="select" cascade="all">
<key>
<column name="orderId" type="java.lang.Integer"/>
</key>
<one-to-many class="dbobjects.LineItem"/>
</set>
</class>
LineItem.java:
public class LineItem {
public LineItem(){
super();
}
private int orderItemId;//this will be the primary key
private int orderId;//this is the foreign key to the order
private String age;
private String gender;
private String type;
private String itemSize;
private int itemQuantity;
}
lineItem.hbm.xml:
<id column="order_item_id" name="orderItemId" type="integer">
<generator class="increment"/>
</id>
<property column="age" name="age" type="string"/>
<property column="gender" name="gender" type="string"/>
<property column="quantity" name="itemQuantity" type="integer"/>
<property column="size" name="itemSize" type="string"/>
<property column="clothing_type" name="clothingType" type="string"/>
<many-to-one name="orderId" class="dbobjects.Order" fetch="select" column="order_id" type="java.lang.Integer"/>
This is where the error is thrown when I Instanciate the session:
**session = HibernateUtil.getSessionFactory().openSession();**←
try{
session.beginTransaction();
session.save(order);
session.getTransaction().commit();
So the question is: How do I handle this situation with 'autoincrement' primary key that is not accessible to another table as a foreign key

So, There were a few problems:
In order to submit a 'child' to the database, I needed to show who is the parent.
This means that my LineItem Class needed a
Order order;
property instead of a simple
private String orderID;
this was accomplished after the Order object was ready to be submitted to the DB but before the actual call:
for (LineItem item : order.getItems()) {
item.setOrder(order);
}
I also changed my DTD's from !DOCTYPE hibernate-configuration SYSTEM classpath://org/hibernate/hibernate-mapping-3.0.dtd"
to
!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"

Just add "type" attribute like this :
<column name="orderId" type="java.lang.Integer"/>

Try to replace :
<many-to-one name="orderId" column="order_id" class="dbobjects.Order" cascade="all">
<column name="orderId" type="java.lang.Integer"/>
</many-to-one>
by
<many-to-one name="orderId" column="order_id" class="dbobjects.Order" cascade="all"/>

How to map a parent to a child with Hibernate?

I have the following classes
class Condition{
public Long id;
public Long ParentConditionId;
public Int order;
}
class NotCondition extends Condition {
public Condition childCondition;
}
class BooleanCondition extends Condition {
public Collection<Condition> children;
}
class StringCondition extends Condition {
public String value;
}
These classes are represented by a condition table with the following columns
Id bigint
Type varchar
ConditionOrder int
StringValue varchar
ParentConditionId bigint
How do I map the NotCondition to its child using hibernate mapping so that the childs ParentConditionId column contains the id of the NotCondition?
My mapping file is
<hibernate-mapping>
<class name="conditions.Condition" table="Condition">
<id column="Id" name="id" access="field">
<generator class="increment"/>
</id>
<discriminator type="string" column="Type"/>
<property name="order" column="ConditionOrder" access="field"/>
<property name="parentConditionId" column="ParentConditionId" access="field"/>
<subclass name="conditions.NotCondition" discriminator-value="NOT">
<!-- What to put here? -->
</subclass>
<subclass name="conditions.BooleanCondition" discriminator-value="BOOLEAN">
<list name="children" access="field" cascade="all" lazy="false">
<key><column name="ParentConditionId"></column></key>
<list-index column="ConditionOrder"/>
<one-to-many class="conditions.Condition"/>
</list>
</subclass>
<subclass name="conditions.StringCondition" discriminator-value="STRING" >
<property name="value" column="StringValue" access="field"/>
</subclass>
</class>
</hibernate-mapping>

explore these :
#Inheritance(strategy=InheritanceType.JOINED)
I suggest you to use annotations..
Below link contains both Annatation and xml configurations..
link here

First, in class Condition, I would replace:
public Long ParentConditionId;
with:
public Condition parentCondition;
I would map is like so:
<many-to-one name="parentCondition" class="conditions.Condition" column="ParentConditionId" />
then, I would map childCondition (in subclass NotCondition) as:
<one-to-one name="childCondition" class="conditions.Condition" property-ref="parentCondition" />

Hibernate parent/child association. Update parent make child lost all associated objects

I have following classes.
public class Employee {
private int id;
private String firstName;
private String lastName;
private Address address;
private Employer employer;
}
public class Employer {
private int id;
private String name;
private Set<Employee> employees;
}
public class Address {
private int id;
}
public class Project{
private int id;
}
<hibernate-mapping>
<class name="me.hibernate.basic.xml.Employee" table="EMPLOYEE">
<id name="id" type="int" column="id">
<generator class="native" />
</id>
<property name="firstName" column="first_name" type="string" />
<property name="lastName" column="last_name" type="string" />
<many-to-one name="address" column="address" unique="true" class="me.hibernate.basic.xml.Address"/>
<set name="projects" cascade="save-update, delete-orphan" sort="natural">
<key column="employee_proj_id" />
<one-to-many class="me.hibernate.basic.xml.Project" />
</set>
<many-to-one name="employer" column="employer" class="me.hibernate.basic.xml.Employer"/>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="me.hibernate.basic.xml.Employer" table="EMPLOYER">
<id name="id" type="int" column="id">
<generator class="native" />
</id>
<property name="name" column="name" type="string" />
<set name="employees" cascade="save-update, delete-orphan" table="EMPLOYEE">
<key column="employer"/>
<one-to-many class="me.hibernate.basic.xml.Employee" />
</set>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="me.hibernate.basic.xml.Address" table="ADDRESS">
<meta attribute="class-description"> This class contains the address detail. </meta>
<id name="id" type="int" column="id">
<generator class="native" />
</id>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="me.hibernate.basic.xml.Project" table="PROJECT">
<meta attribute="class-description"> This class contains the project detail. </meta>
<id name="id" type="int" column="id">
<generator class="native" />
</id>
</class>
</hibernate-mapping>
In my application I create few Employees and assign an address to them. And add some projects. Then I create an employer and add all the employees to employer. Once I add employees and update the employer, all the employees lose their addresses and projects. How can I do this with keeping lazy loading feature. I don't need to set lazy="false".
Employee emp1 = ME.addEmployee("Zara", "Ali");
Employee emp2 = ME.addEmployee("Daisy", "Das");
Address addr1 = ME.addAddress(35, "xxxxxx Street", "XXXXX", "XY7 0ZZ");
Address addr2 = ME.addAddress(42, "xxxxxx Street", "XXXXX", "XY7 7ZZ");
ME.setAddress(emp1.getId(), addr1);
ME.setAddress(emp2.getId(), addr2);
Set<Project> proj = new HashSet<Project>();
proj.add(new Project("NOVA"));
proj.add(new Project("GTA Simplify"));
proj.add(new Project("Jazz"));
ME.addProjects(emp.getId(), proj);
ME.addProjects(emp.getId(), proj);
All working up to this point.
Set<Employee> emps = new HashSet<Employee>();
emps.add(emp1); emps.add(emp2);
//Add existing employees to employer - Many-to-one bidirectional
Employer employer = ME.addEmployer("XYZ");
ME.addEmployees(employer.getId(), emps);
public Integer addEmployees(Integer employerID, Set<Employee> employees) {
Session session = factory.openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
Employer employer = (Employer) session.get(Employer.class,employerID);
employer.getEmployees().clear();
employer.getEmployees().addAll(employees);
session.update(employer);
tx.commit();
} catch (HibernateException e) {
if (tx != null)
tx.rollback();
e.printStackTrace();
} finally {
session.close();
}
return employerID;
}
Once I added employees, all the foreign key references are lost in the PROJECT.employee_proj_id and EMPLOYEE.address.
Hibernate log:
->Hibernate: update EMPLOYEE set first_name=?, last_name=?, basic=?, address=?, employer=? where id=?
->Hibernate: update EMPLOYEE set first_name=?, last_name=?, basic=?, address=?, employer=? where id=?
->Hibernate: update PROJECT set employee_proj_id=null where employee_proj_id=?
->Hibernate: update PROJECT set employee_proj_id=null where employee_proj_id=?
->Hibernate: update EMPLOYEE set employer=? where id=? ->Hibernate: update EMPLOYEE set employer=? where id=?

I see that you are clearing the employees before you add more employees, which is the root cause of everything. I'm not sure what you are doing when adding addresses, Project, employer etc., You need not clear the employees. If you have cascadetype.all set on the employees then saving the employer will update the newly added employees.
employer.getEmployees().clear();//remove this line.
employer.getEmployees().addAll(employees);

hibernate change the column name in a select

I have a table (node) with 3 data
- id(pk)
- question
- result
and 2 foreign key (many-to-one)
- LEFT_ID
- RIGHT_ID
here my hbm
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.beans.Nodes" table="node">
<id name="id" type="int" access="field">
<column name="id" />
<generator class="assigned" />
</id>
<property name="question" type="java.lang.String">
<column name="question" />
</property>
<property name="result" type="java.lang.String">
<column name="result" />
</property>
<many-to-one column="LEFT_ID" name="left" class="com.beans.Nodes" insert="false" update="false"></many-to-one>
<many-to-one column="RIGHT_ID" name="right" class="com.beans.Nodes" insert="false" update="false"></many-to-one>
</class>
</hibernate-mapping>
and my bean with getter/setter on LEFT/RIGHT_ID
#Entity
#Table (name = "node")
public class Nodes
{
#Id
#GeneratedValue (strategy = GenerationType.IDENTITY)
#Column(name="id")
private int id;
#Column (name = "question")
private String question;
#Column ( name = "result")
private String result;
private Nodes LEFT_ID;
private Nodes RIGHT_ID;
public Nodes getLeftNodes()
{
return LEFT_ID;
}
public void setLeftNodes(Nodes LEFT_ID)
{
this.LEFT_ID=LEFT_ID;
}
public Nodes getRightNodes()
{
return RIGHT_ID;
}
public void setRifhtNodes(Nodes right)
{
this.RIGHT_ID=right;
}
}
But when i deploy my project, i have this error
**Query: ReadAllQuery(referenceClass=Nodes sql="SELECT id, question, result, LEFT_ID_id, RIGHT_ID_id FROM node")**
When hibernate is a select, he change the name of the column. LEFT_ID becomes LEFT_ID_id and inevitably he finds nothing !
Why hibernate change the name of the LEFT_ID column ?
thanks