HIBERNATE (WITH @NNOTATION) IN WEB APPLICATION

In this post, am going to cover the basic way to setup the hibernate environment in eclipse to do a simple insert operation in mysql database and this post is meant for beginners who doesn't know about hibernate configurations coz am similar kind. I can't post this in codeproject coz it requires some more documentation so if you want the project files message me in G+ I will post you the project files.

Folder structure & Libraries required:

It gives clear details about file placement and libraries required.

Application setup:

· JDK 6

· Eclipse Juno

· Tomcat 7.0

· MySQL 5.1

· Supporting libraries for hibernate.

Steps:

· Creating project in Eclipse.

· Loading JARs.

· Configuring and Adding classes.

· Run.

Create Project in Eclipse:

· Open – Eclipse > Go to > File > New > Dynamic web project.

Loading JARs

Add all the required JARs in in the folder lib which resides inside web content > web-inf.

Location: ‘Projectname/WebContent/WEB-INF/lib ’.

After adding those JARs into the lib directory need to include them into project.

· Right click on project > select Build path > Configuration Build Path.

· Select Java Build path from sidebar menu and select Libraries tab > select Add JARs.

Configuring and Adding classes:

Add ‘hibernate.cfg.xml’ in the location ‘Projectname/JavaResources/src/’ and load the below code to it.

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>

<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>

<property name="hibernate.connection.url">jdbc:mysql://localhost:5050/dbName</property>

<property name="connection.password">password</property>

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="hbm2ddl.auto">create</property>

</session-factory>

</hibernate-configuration>

Add the below code in web.xml

<display-name>HibernateController</display-name>

<servlet-name>HibernateController</servlet-name>

<servlet-class>service.HibernateController</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>HibernateController</servlet-name>

<url-pattern>*.do</url-pattern>

</servlet-mapping>

Class Creation

Create util package:

Create package in the name “util” inside “src” folder > create the class “HibernateUtil” > Load the below code into the class created.

package util;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.AnnotationConfiguration;

public class HibernateUtil {

private static final SessionFactory sessionFactory;

static {

try {

sessionFactory = new AnnotationConfiguration().configure()

.buildSessionFactory();

} catch (Throwable ex) {

throw new ExceptionInInitializerError(ex);

}

public static SessionFactory getSessionFactory() {

return sessionFactory;

}

Create model package:

Create package in the name “model” inside “src” folder > create the entity classes here in this sample I have created to classes “Department” and “student” and load the below code into the classes created respectively.

package modal;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.Table;

@Entity

@Table(name="Department")

public class Department {

int deptID;

String deptName;

String HOD;

public Department() {

}

public Department(String deptName,String HOD) {

this.deptName = deptName;

this.HOD=HOD;

}

@Id

@GeneratedValue

@Column(name="Dept_ID")

public int getDeptID() {

return deptID;

}

public void setDeptID(int deptID) {

this.deptID = deptID;

}

@Column(name="Dept_Name", nullable=false)

public String getDeptName() {

return deptName;

}

public void setDeptName(String deptName) {

this.deptName = deptName;

}

@Column(name="HOD", nullable=false)

public String getHOD() {

return HOD;

}

public void setHOD(String hOD) {

HOD = hOD;

}

package modal;

import java.util.HashSet;

import java.util.Set;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.Table;

import javax.persistence.JoinTable;

import javax.persistence.ManyToMany;

import javax.persistence.JoinColumn;

import javax.persistence.CascadeType;

@Entity

@Table(name="Student")

public class Student {

private long rollNo;

private String name;

private Set dept= new HashSet(0);

public Student() {

}

public Student(String name) {

this.name = name;

}

public Student(String name, Set dept) {

this.name = name;

this.dept = dept;

}

@Id

@GeneratedValue

@Column(name="RollNo")

public long getRollNo() {

return rollNo;

}

public void setRollNo(long rollNo) {

this.rollNo = rollNo;

}

@Column(name="Name", nullable=false)

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

@ManyToMany(cascade = CascadeType.ALL)

@JoinTable(name = "STUDENT_COURSE", joinColumns = { @JoinColumn(name = "STUDENT_ID") }, inverseJoinColumns = { @JoinColumn(name = "COURSE_ID") })

public Set getCourses() {

return this.dept;

}

public void setCourses(Set dept) {

this.dept = dept;

}

Create service package:

Create package in the name “service” inside “src” folder > create the servlet “HibernateController” > Load the below code.

package service;

import java.util.HashSet;

import java.util.Set;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.Transaction;

import modal.Department;

import modal.Student;

import util.HibernateUtil;

/**

* Servlet implementation class HibernateController

public class HibernateController extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

* @see HttpServlet#HttpServlet()

public HibernateController() {

super();

// TODO Auto-generated constructor stub

}

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

}

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

Session session = HibernateUtil.getSessionFactory().openSession();

Transaction transaction = null;

try {

transaction = session.beginTransaction();

Set dept = new HashSet();

dept.add(new Department("IT","Sreekanth"));

dept.add(new Department("Admin","Senthil"));

Student student1 = new Student("Sahana", dept);

Student student2 = new Student("Reshma", dept);

session.save(student1);

session.save(student2);

transaction.commit();

} catch (HibernateException e) {

transaction.rollback();

} finally {

session.close();

}

response.getWriter().println("Created");

}

Create an index.jsp:

For testing we are just going to create a sample a page and place button in that. On click of the button we are just going to trigger the event to do the hibernate functionalities.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

</head>

<body>

</form>

</body>

</html>

You gone through everything, gr8!!! Post your feedback so that I could improvise this post to help beginners like me :) :)

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