Hibernate 4 Example
In this tutorials, we are going to implement a complete CRUD application using Hibernate annotations and MySQL. The same example using xml configuration, we have developed in the previous tutorial – Hibernate CRUD using XML Configuration.
The present tutorial is for Hibernate 4 Example with annotation-based configuration using maven.
Technologies :
- Hibernate-core 4.0
- Mysql 5.5.43
- NetBeans 8.0
Setup Database:
Create Database
mysql> create database onlinetutorialspoint;
mysql> use onlinetutorialspoint;
Then create a student table in onlinetutorialspoint database.
Creating Student table
CREATE TABLE `student` (
`id` INT(10) NOT NULL AUTO_INCREMENT,
`name` VARCHAR(50) NULL DEFAULT NULL,
`rollnumber` INT(10) NULL DEFAULT NULL,
`gender` TINYINT(4) NULL DEFAULT NULL,
`class` VARCHAR(50) NULL DEFAULT NULL,
`lastupdated` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
);Project Structure:
Maven Dependencies:
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.onlinetutorialspoint</groupId>
<artifactId>HibernateMaven</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<repositories>
<repository>
<id>JBoss repository</id>
<url>http://repository.jboss.com/maven2/</url>
</repository>
<repository>
<id>unknown-jars-temp-repo</id>
<name>A temporary repository created by NetBeans for libraries and jars it could not identify. Please replace the dependencies in this repository with correct ones and delete this repository.</name>
<url>file:${project.basedir}/lib</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.0.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>4.2.0.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate.common</groupId>
<artifactId>hibernate-commons-annotations</artifactId>
<version>4.0.1.Final</version>
<classifier>tests</classifier>
</dependency>
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
<version>1.0.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.1.8.Final</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.0.0.GA</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.6.4</version>
</dependency>
<dependency>
<groupId>org.jboss.logging</groupId>
<artifactId>jboss-logging</artifactId>
<version>3.1.0.CR2</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.6.4</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.10</version>
</dependency>
<dependency>
<groupId>mysql-connector</groupId>
<artifactId>mysql-connector-java-5.1.23-bin</artifactId>
<version>SNAPSHOT</version>
</dependency>
</dependencies>
</project>Above is the pom.xml, where we can define all required maven dependencies.
Create Hibernate Configuration:
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>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/onlinetutorialspoint?zeroDateTimeBehavior=convertToNull</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">XYZ-ABC</property>
<!--Here we are mapping Pojo class not hbm-->
<mapping class="com.onlinetutorialspoint.pojo.Student" />
</session-factory>
</hibernate-configuration>Create Hibernate Utils:
Create HibernateConnector.java, responsible to create singleton session factory object and to connect with the database.
HibernateConnector.java
package com.onlinetutorialspoint.config;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateConnector {
private static HibernateConnector me;
private Configuration cfg;
private SessionFactory sessionFactory;
private HibernateConnector() throws HibernateException {
// build the config
cfg = new Configuration().configure();
sessionFactory = cfg.buildSessionFactory();
}
public static synchronized HibernateConnector getInstance() throws HibernateException {
if (me == null) {
me = new HibernateConnector();
}
return me;
}
public Session getSession() throws HibernateException {
Session session = sessionFactory.openSession();
if (!session.isConnected()) {
this.reconnect();
}
return session;
}
private void reconnect() throws HibernateException {
this.sessionFactory = cfg.buildSessionFactory();
}
}Create Pojo class with respect to the student table.
Student.java
package com.onlinetutorialspoint.pojo;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "student", catalog = "onlinetutorialspoint"
)
public class Student implements java.io.Serializable {
private Integer id;
private String name;
private Integer rollnumber;
private Byte gender;
private String class_;
public Student() {
}
public Student(String name, Integer rollnumber, Byte gender, String class_) {
this.name = name;
this.rollnumber = rollnumber;
this.gender = gender;
this.class_ = class_;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "id", unique = true, nullable = false)
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
@Column(name = "name", length = 50)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
@Column(name = "rollnumber")
public Integer getRollnumber() {
return this.rollnumber;
}
public void setRollnumber(Integer rollnumber) {
this.rollnumber = rollnumber;
}
@Column(name = "gender")
public Byte getGender() {
return this.gender;
}
public void setGender(Byte gender) {
this.gender = gender;
}
@Column(name = "class", length = 50)
public String getClass_() {
return this.class_;
}
public void setClass_(String class_) {
this.class_ = class_;
}
}Points to Note :
@Entity: Is an EJB 3 standard annotation, used to specify the class is an entity. By using this annotation we are going to tell the hibernate, treat this class as an Entity.
@Table: @Table annotation comes from javax.persistence, used to specify the primary table to the annotated Entity. We do configure the secondary tables too, by using the @SecondaryTable annotation.
@Id and @GeneratedValue: In hibernate, each entity will have the primary key or keys (composite). We can configure the primary keys by using the @id annotation. The type of the particular primary key will be defined as @GeneratedValue.
@Column: annotation is used to specify the mapped column with persistent property. It represents the table column with entity class field.
Note: No need to create “hbm.xml”, as this is an annotation based example.
Create Data Access Object (DAO)
Create StudentDAO.java to access the Student details.
StudentDAO.java
package com.onlinetutorialspoint.dao;
import com.onlinetutorialspoint.config.HibernateConnector;
import com.onlinetutorialspoint.pojo.Student;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
public class StudentDAO {
public List<Student> listStudent() {
Session session = null;
try {
session = HibernateConnector.getInstance().getSession();
Query query = session.createQuery("from Student s");
List queryList = query.list();
if (queryList != null && queryList.isEmpty()) {
return null;
} else {
System.out.println("list " + queryList);
return (List<Student>) queryList;
}
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
session.close();
}
}
public Student findStudentById(int id) {
Session session = null;
try {
session = HibernateConnector.getInstance().getSession();
Query query = session.createQuery("from Student s where s.id = :id");
query.setParameter("id", id);
List queryList = query.list();
if (queryList != null && queryList.isEmpty()) {
return null;
} else {
return (Student) queryList.get(0);
}
} catch (Exception e) {
e.printStackTrace();
return null;
} finally {
session.close();
}
}
public void updateStudent(Student student) {
Session session = null;
try {
session = HibernateConnector.getInstance().getSession();
session.saveOrUpdate(student);
session.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
public Student addStudent(Student student) {
Session session = null;
Transaction transaction = null;
try {
session = HibernateConnector.getInstance().getSession();
System.out.println("session : "+session);
transaction = session.beginTransaction();
session.save(student);
transaction.commit();
return student;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public void deleteStudent(int id) {
Session session = null;
try {
session = HibernateConnector.getInstance().getSession();
Transaction beginTransaction = session.beginTransaction();
Query createQuery = session.createQuery("delete from Student s where s.id =:id");
createQuery.setParameter("id", id);
createQuery.executeUpdate();
beginTransaction.commit();
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
}Hibernate Client
Create a client class, from which we can access the StudentDAO.java to make CRUD operations.
DbOperations.java
package com.onlinetutorialspoint.service;
import com.onlinetutorialspoint.dao.StudentDAO;
import com.onlinetutorialspoint.pojo.Student;
import java.util.List;
public class DbOperations {
StudentDAO studentDAO = new StudentDAO();
public static void main(String[] args) {
DbOperations dbOperations = new DbOperations();
Student createStudent = dbOperations.createStudent();
List<Student> studentList = dbOperations.getStudentList();
if (studentList != null) {
for (Student student : studentList) {
System.out.println("Student Name : " + student.getName());
}
}
dbOperations.updateStudent(createStudent.getId());
Student student = dbOperations.getStudent(createStudent.getId());
if (student != null) {
System.out.println("Student Details After Updation : " + student.getName());
}
dbOperations.deleteStudent(createStudent.getId());
}
public Student createStudent() {
Student s = new Student();
s.setGender(new Byte("1"));
s.setName("smith");
s.setClass_("12");
s.setRollnumber(007);
studentDAO.addStudent(s);
return s;
}
public void updateStudent(Integer id) {
Student student = studentDAO.findStudentById(id);
student.setName("online tutorials point");
studentDAO.updateStudent(student);
System.out.println("Student Updated Success");
}
public void deleteStudent(Integer id) {
studentDAO.deleteStudent(id);
System.out.println("Student Deleted Success");
}
public List<Student> getStudentList() {
return studentDAO.listStudent();
}
public Student getStudent(Integer id) {
return studentDAO.findStudentById(id);
}
}Output :
Console
Student Name : smith Student Updated Success Student Details After Updation : online tutorials point Student Deleted SuccessHappy Learning 🙂
