Java/Hibernate/Criteria Projection
Criteria: Projection Criteria
/////////////////////////////////////////////////////////////////////////
import java.util.*;
import java.sql.*;
import org.hibernate.*;
import org.hibernate.criterion.*;
public class Main {
public static void main(String[] args) {
HibernateUtil.setup("create table Supplier ( id int, name VARCHAR);");
HibernateUtil.setup("create table Product ( id int, name VARCHAR, description VARCHAR, price double,supplierId int);");
prepareData();
Session session = HibernateUtil.currentSession();
Criteria crit = session.createCriteria(Product.class);
ProjectionList projList = Projections.projectionList();
projList.add(Projections.property("name"));
projList.add(Projections.property("description"));
crit.setProjection(projList);
List results = crit.list();
displayObjectsList(results);
HibernateUtil.checkData("select * from Supplier");
HibernateUtil.checkData("select * from Product");
}
static public void displayObjectsList(List list)
{
Iterator iter = list.iterator();
if (!iter.hasNext())
{
System.out.println("No objects to display.");
return;
}
while (iter.hasNext())
{
System.out.println("New object");
Object[] obj = (Object[]) iter.next();
for (int i=0;i<obj.length;i++)
{
System.out.println(obj[i]);
}
}
}
private static void prepareData(){
Session session = HibernateUtil.currentSession();
Supplier supplier1 = new Supplier();
supplier1.setName("Supplier Name 1");
session.save(supplier1);
Supplier supplier2 = new Supplier();
supplier2.setName("Supplier Name 2");
session.save(supplier2);
Product product1 = new Product("Product 1","Name for Product 1", 2.0);
product1.setSupplier(supplier1);
supplier1.getProducts().add(product1);
session.save(product1);
Product product12 = new Product("Product 2","Name for Product 2", 22.0);
product12.setSupplier(supplier1);
supplier1.getProducts().add(product12);
session.save(product12);
Product product2 = new Product("Product 3", "Name for Product 3", 30.0);
product2.setSupplier(supplier2);
supplier2.getProducts().add(product2);
session.save(product2);
session.flush();
HibernateUtil.closeSession();
}
}
/////////////////////////////////////////////////////////////////////////
public class Product
{
private int id;
private Supplier supplier;
private String name;
private String description;
private double price;
public Product()
{
super();
}
public Product(String name, String description, double price)
{
super();
this.name = name;
this.description = description;
this.price = price;
}
public String getDescription()
{
return description;
}
public void setDescription(String description)
{
this.description = description;
}
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public Supplier getSupplier()
{
return supplier;
}
public void setSupplier(Supplier supplier)
{
this.supplier = supplier;
}
public double getPrice()
{
return price;
}
public void setPrice(double price)
{
this.price = price;
}
}
/////////////////////////////////////////////////////////////////////////
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Supplier">
<id name="id" type="int">
<generator class="increment"/>
</id>
<property name="name" type="string"/>
<bag name="products" inverse="true" cascade="all,delete-orphan">
<key column="supplierId"/>
<one-to-many class="Product"/>
</bag>
</class>
</hibernate-mapping>
/////////////////////////////////////////////////////////////////////////
import java.util.ArrayList;
import java.util.List;
public class Supplier
{
private int id;
private String name;
private List products = new ArrayList();
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public List getProducts()
{
return products;
}
public void setProducts(List products)
{
this.products = products;
}
}
/////////////////////////////////////////////////////////////////////////
Criteria: Row Count Criteria
/////////////////////////////////////////////////////////////////////////
import java.util.*;
import java.sql.*;
import org.hibernate.*;
import org.hibernate.criterion.*;
public class Main {
public static void main(String[] args) {
HibernateUtil.setup("create table Supplier ( id int, name VARCHAR);");
HibernateUtil.setup("create table Product ( id int, name VARCHAR, description VARCHAR, price double,supplierId int);");
prepareData();
Session session = HibernateUtil.currentSession();
Criteria crit = session.createCriteria(Product.class);
crit.setProjection(Projections.rowCount());
List results = crit.list();
displayObjectList(results);
HibernateUtil.checkData("select * from Supplier");
HibernateUtil.checkData("select * from Product");
}
static public void displayObjectList(List list)
{
Iterator iter = list.iterator();
if (!iter.hasNext())
{
System.out.println("No objects to display.");
return;
}
while (iter.hasNext())
{
Object obj = iter.next();
System.out.println(obj);
}
}
private static void prepareData(){
Session session = HibernateUtil.currentSession();
Supplier supplier1 = new Supplier();
supplier1.setName("Supplier Name 1");
session.save(supplier1);
Supplier supplier2 = new Supplier();
supplier2.setName("Supplier Name 2");
session.save(supplier2);
Product product1 = new Product("Product 1","Name for Product 1", 2.0);
product1.setSupplier(supplier1);
supplier1.getProducts().add(product1);
session.save(product1);
Product product12 = new Product("Product 2","Name for Product 2", 22.0);
product12.setSupplier(supplier1);
supplier1.getProducts().add(product12);
session.save(product12);
Product product2 = new Product("Product 3", "Name for Product 3", 30.0);
product2.setSupplier(supplier2);
supplier2.getProducts().add(product2);
session.save(product2);
session.flush();
HibernateUtil.closeSession();
}
}
/////////////////////////////////////////////////////////////////////////
public class Product
{
private int id;
private Supplier supplier;
private String name;
private String description;
private double price;
public Product()
{
super();
}
public Product(String name, String description, double price)
{
super();
this.name = name;
this.description = description;
this.price = price;
}
public String getDescription()
{
return description;
}
public void setDescription(String description)
{
this.description = description;
}
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public Supplier getSupplier()
{
return supplier;
}
public void setSupplier(Supplier supplier)
{
this.supplier = supplier;
}
public double getPrice()
{
return price;
}
public void setPrice(double price)
{
this.price = price;
}
}
/////////////////////////////////////////////////////////////////////////
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Supplier">
<id name="id" type="int">
<generator class="increment"/>
</id>
<property name="name" type="string"/>
<bag name="products" inverse="true" cascade="all,delete-orphan">
<key column="supplierId"/>
<one-to-many class="Product"/>
</bag>
</class>
</hibernate-mapping>
/////////////////////////////////////////////////////////////////////////
import java.util.ArrayList;
import java.util.List;
public class Supplier
{
private int id;
private String name;
private List products = new ArrayList();
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public List getProducts()
{
return products;
}
public void setProducts(List products)
{
this.products = products;
}
}
/////////////////////////////////////////////////////////////////////////
