Hibernate (Part 2): configuration and use

Hibernate configuration in a Java application

Install JDK 1.4 or JDK 1.5.

Download version 3 from hibernaterg

Reference the Hibernate jars in the classpath.

Define the Hibernate configuration file (hibernatefg.xml):

This file must be placed in the directory containing the source code of the JAVA application (recommended).

Below is an example of hibernatefg.xml file with necessary comments:

/p>

PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"

"[http://hibernaterg/dtd/hibernate-configuration-3.0.dtd">

jdbc:oracle:thin:@dbServer:1521:db

oracle.jdbc.OracleDriver

org.hibernate.dialect.Oracle9Dialect

dbusername

dbpassword

true

true

true

1

false

50

true

org.hibernateonnection.C3P0ConnectionProvider

3

180

100

10

1000

org.hibernateache.NoCacheProvider

Define the hbm mapping files:

This is a set of files that makes the mapping between the entity database and associated JAVA objects.

Full paths of all hbm mapping files are described in configuration file (hibernatefg.xml).

Using Hibernate in a Java application:

In this example we will use the Hibernate configuration file:

Declaration of the table (Oracle)

CREATE TABLE CLIENT

(

ID_Client NUMBER(10) NOT NULL,

TITRE VARCHAR2(10),

NOM VARCHAR2(30),

REMISE NUMBER(19,5),

CA NUMBER(19,5),

CONSTRAINT PK_CLIENT PRIMARY KEY (CLIENT_ID)

);

Declaration of JAVA classes

/** constructeur par défaut */

public Client() {

}

/** Constructeur complet **/

public Client(Long clientId, String titre, String nom, BigDecimal remise, BigDecimal ca)

{

this.idClient = idClient;

thiitre = titre;

thiame = name;

thiemise = remise;

thia = ca;

}

/** Les getters et setters**/

public Long getIdClient()

{

return thilientId;

}

public void setIdClient (Long clientId) {

thilientId = clientId;

}

public String getTitre() {

return thiitre;

}

public void setTitre(String titre) {

thiitre = titre;

}

public String getNom() {

return thiom;

}

public void setNom(String nom) {

thiom = nom;

}

public BigDecimal getRemise() {

return thiemise;

}

public void setRemise(BigDecimal remise) {

thiemise = remise;

}

public BigDecimal getCa() {

return thia;

}

public void setCa(BigDecimal ca) {

thia = ca;

}

}

Client.hbm.xml mapping files:

/p>

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernaterg/dtd/hibernate-mapping-3.0.dtd" >

name="[Nom_Package].Client"

table="CLIENT"

entity-name="Client"

>

@hibernatelass

table="CLIENT"

name="idClient"

type="java.lang.Long"

column="ID_CLIENT"

>

Id du client

@hibernate.id

generator-class="assigned"

type="java.lang.Long"

column="CLIENT_ID"

name="titre"

type="java.lang.String"

column="TITRE"

length="10"

>

Titre du client

@hibernate.property

column="TITRE"

length="10"

name="name"

type="java.lang.String"

column="NAME"

length="30"

>

Nom du client

@hibernate.property

column="NAME"

length="30"

name="remise"

type="javaath.BigDecimal"

column="REMISE"

length="19"

>

Remise du client

@hibernate.property

column="REMISE"

length="19"

name="ca"

type="javaath.BigDecimal"

column="CA"

length="19"

>

Chiffre Affaire

The primary key is defined in the tag: in our example, it is based on a sequence. It is possible to define a composite key using the tag:

composite-id>

Saving a new object in the database:

The example below uses the saveOrUpdate () method of the Hibernate session.

org.hibernate.Session sess = sessFacpenSession(); Client c = new Client(); c.setName("John"); p.setTitre("Mr"); Transaction tx = sess.beginTransaction(); sess.saveOrUpdate(p); ommit(); seslose();