Spring Hibernate integration

In this post we will see an example of how to integrate hibernate with spring. The steps are self explanatory as they are very similar to the steps for using JdbcTemplate.

Points to ponder:

• @Entity : This annotation states that the POJO class as an entity.
• @Id : This annotation declares the identifier property of this entity.
• <context:annotation-config/> : It is used to activate annotations in beans already registered in the application context.
• <context:component-scan/> : It scans packages to find and register beans within the application context.
• @Repository : This annotation is a stereotype for persistence layer. It indicates that the class defines a data repository.
• @Autowired : @Autowired indicates that spring should inject dependency, based on its type or based on its name if used with the @Qualifier annotation.

File: com.ram.model.Departments.java

package com.ram.model;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Departments {
 @Id
 private int department_id;
 private String department_name;
 private int manager_id;
 private int location_id;
 
 public int getDepartment_id() {
  return department_id;
 }
 public void setDepartment_id(int department_id) {
  this.department_id = department_id;
 }
 public String getDepartment_name() {
  return department_name;
 }
 public void setDepartment_name(String department_name) {
  this.department_name = department_name;
 }
 public int getManager_id() {
  return manager_id;
 }
 public void setManager_id(int manager_id) {
  this.manager_id = manager_id;
 }
 public int getLocation_id() {
  return location_id;
 }
 public void setLocation_id(int location_id) {
  this.location_id = location_id;
 }
 
}

Next create applicationContext.xml file under src. The file is given below.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
       http://www.springframework.org/schema/context 
       http://www.springframework.org/schema/context/spring-context-3.0.xsd
       http://www.springframework.org/schema/aop 
       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
 
    <context:annotation-config/>
 
    <context:component-scan base-package="com.ram.dao"></context:component-scan>
 
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/>
        <property name="url" value="jdbc:oracle:thin:@localhost:1521:xe"/>
        <property name="username" value="hr"/>
        <property name="password" value="hr"/>
        <property name="initialSize" value="2"/>
        <property name="maxActive" value="5"/>
    </bean>
       
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
  <property name="dataSource" ref="dataSource"/>
  <property name="packagesToScan" value="com.ram.model"></property>
      
  <property name="hibernateProperties">
      <props>
     <prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</prop>
     <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
      </props>
  </property>
    </bean>
 
</beans>

File: com.ram.dao.DepartmentsDaoImpl.java

package com.ram.dao;

import org.hibernate.Query;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository
public class DepartmentsDaoImpl {
 @Autowired
 private SessionFactory sessionFactory;
 
 public int getDepartmentsCount(){
  String hql = "select count(*) from Departments";
  Query query = getSessionFactory().openSession().createQuery(hql);
  return ((Long)query.uniqueResult()).intValue();
 }
 
 public SessionFactory getSessionFactory() {
  return sessionFactory;
 }

 public void setSessionFactory(SessionFactory sessionFactory) {
  this.sessionFactory = sessionFactory;
 }
 
}

File: com.ram.main.DepartmentsApp.java

package com.ram.main;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.ram.dao.DepartmentsDaoImpl;

public class DepartmentsApp {
 public static void main(String[] args) {
  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
  DepartmentsDaoImpl departmentsDaoImpl = context.getBean("departmentsDaoImpl",DepartmentsDaoImpl.class);
  System.out.println("Total rows in departments table = "+departmentsDaoImpl.getDepartmentsCount());
 }
}

Execute DepartmentsApp.java file. Output is given below.