Hibernate XML Mapping

--Ads--

Hibernate XML Mapping

In this section, you will learn how to do XML mapping in Hibernate.

In Hibernate, XML file is used for two things : First, for configuring the database(hibernate.cfg.xml), Second, for mapping database table to POJO class.

The sample XML file used for configuring the database is given below :

hibernate.cfg.xml

<?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>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://192.168.10.13:3306/anky</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>

<property name="connection.pool_size">1</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="current_session_context_class">thread</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">validate</property>

<mapping class="net.roseindia.WorkerDetail"/>
<mapping class="net.roseindia.Worker"/>

</session-factory>
</hibernate-configuration>

XML Mapping

The sample XML mapping file used for mapping Java class to database table is given below :

person.hbm.xml

<?xml version='1.0'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="roseindia">
<class name="Person" table="person">
<id name="id" type="int" column="Id" >
<generator class="assigned"/>
</id>

<property name="name">
<column name="Name" />
</property>

</class>
</hibernate-mapping>

XML one to one mapping

The XML mapping file used in one-to-one mapping is given below :

Worker.hbm.xml

<?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 package="net.roseindia">

<class name="Worker" table="worker">
<id name="workerId" column="worker_id">
<generator class="native" />
</id>
<one-to-one name="workerDetail" class="net.roseindia.WorkerDetail"
cascade="save-update"></one-to-one>

<property name="firstname" column="firstname" />
<property name="lastname" column="lastname" />
<property name="birthDate" type="date" column="birth_date" />
<property name="cellphone" column="cell_phone" />

</class>
</hibernate-mapping>

WorkerDetail.hbm.xml

<?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 package="net.roseindia">

<class name="WorkerDetail" table="workerdetail">

<id name="workerId" type="java.lang.Long">
<column name="worker_id" />
<generator class="foreign">
<param name="property">worker</param>
</generator>
</id>
<one-to-one name="worker" class="net.roseindia.Worker"
constrained="true"></one-to-one>

<property name="street" column="street" />
<property name="city" column="city" />
<property name="state" column="state" />
<property name="country" column="country" />
</class>

</hibernate-mapping>

XML One to Many Mapping

The one to many relation between two tables is shown below :

The XML one-to-many mapping is given below:

Address.hbm.xml

<?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 package="net.roseindia">
<class name="Address" table="address">
<id name="addressId" column="address_id">
<generator class="native" />
</id>
<property name="street" column="street"/>
<property name="city" column="city"/>
<property name="state" column="state"/>
<property name="country" column="country"/>
<set name="employees" table="employee"
inverse="true" lazy="true" fetch="select">
<key>
<column name="address_id" not-null="true" />
</key>
<one-to-many class="net.roseindia.Employee" />
</set>
</class>
</hibernate-mapping>

Employee.hbm.xml

<?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 package="net.roseindia">

<class name="Employee" table="employee">
<id name="employeeId" column="employee_id">
<generator class="native" />
</id>

<property name="firstname" column="firstname"/>
<property name="lastname" column="lastname" />
<property name="cellphone" column="cell_phone" />

<many-to-one name="address" class="net.roseindia.Address" fetch="select">
<column name="address_id" not-null="true" />
</many-to-one>

</class>
</hibernate-mapping>

XML Many to Many Mapping

The XML Many to Many relation shown below using figure:

The XML many-to-many mapping is given below :

Student.hbm.xml

<?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 package="net.roseindia">
<class name="Student" table="student">
<id name="studentId" column="student_id">
<generator class="native" />
</id>

<property name="studentName" column="student_name"/>

<set name="courses" table="student_course"
inverse="false" lazy="true" fetch="select" cascade="all">
<key column="student_id" />
<many-to-many column="course_id" class="Course" />
</set>
</class>
</hibernate-mapping>

Course.hbm.xml

<?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 package="net.roseindia">
<class name="Course" table="course">
<id name="courseId" column="course_id">
<generator class="native" />
</id>

<property name="courseName" column="course_name"/>

<set name="students" table="student_course"
inverse="false" lazy="true" fetch="select" cascade="all">
<key column="student_id" />
<many-to-many column="course_id" class="Course" />
</set>
</class>
</hibernate-mapping>

Hibernate XML Mapping