Hibernate JPA With H2 Database
Hibernate JPA With H2 Database explains step by step details of setting / configuring Java Persistence JPA With Hibernate And H2
How To Configure Hibernate JPA With H2?
Java Persistence API, is a standard interface which wraps different ORM tools such as Hibernate, EclipseLink, OpenJPA etc.
ie; you can able to change Hibernate implementation to EclipseLink implementation without changing the code base.
On this standalone JPA Example, we are using Java Persistence With H2 Database
Hibernate is popular open source ORM (Object Relation Mapping) tool for Java platform, for mapping an entity to a traditional relational like Oracle, MySQL, SQL Server, PostgreSQL, DB2, Derby, Sybase, H2 etc
I am going to reuse JPA Tutorial With Hibernate
You can check below different database with Hibernate and EclipseLink examples
Modify persistence.xml
persistence.xml file must be under src/META-INF (Please check below screenshot(project structure)
Here we are using hibernate.dialect as "org.hibernate.dialect.H2Dialect". Below persistence.xml, we are using in-memory database, you can change this to file database by changing the URL to jdbc:h2:~/test
<persistence xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"> <persistence-unit name="test" transaction-type="RESOURCE_LOCAL"> <class>com.test.jpa.Student</class> <properties> <property name="javax.persistence.jdbc.driver" value="org.h2.Driver" /> <property name="javax.persistence.jdbc.url" value="jdbc:h2:mem:test" /> <property name="javax.persistence.jdbc.user" value="sa" /> <property name="javax.persistence.jdbc.password" value="" /> <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/> <property name="hibernate.hbm2ddl.auto" value="create-drop" /> <property name="show_sql" value="true"/> <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/> </properties> </persistence-unit> </persistence>
Package Structure
Now package structure looks like following
Testing (JPAExample.java)
import java.util.Iterator;
import java.util.List;
import javax.persistence.EntityManager;
//Hibernate JPA With H2 Example
public class JPAExample {
private EntityManager entityManager = EntityManagerUtil.getEntityManager();
public static void main(String[] args) {
JPAExample example = new JPAExample();
System.out.println("After Sucessfully insertion ");
Student student1 = example.saveStudent("Sumith");
Student student2 = example.saveStudent("Anoop");
example.listStudent();
System.out.println("After Sucessfully modification ");
example.updateStudent(student1.getStudentId(), "Sumith Honai");
example.updateStudent(student2.getStudentId(), "Anoop Pavanai");
example.listStudent();
System.out.println("After Sucessfully deletion ");
example.deleteStudent(student2.getStudentId());
example.listStudent();
}
public Student saveStudent(String studentName) {
Student student = new Student();
try {
entityManager.getTransaction().begin();
student.setStudentName(studentName);
student = entityManager.merge(student);
entityManager.getTransaction().commit();
} catch (Exception e) {
entityManager.getTransaction().rollback();
}
return student;
}
public void listStudent() {
try {
entityManager.getTransaction().begin();
@SuppressWarnings("unchecked")
List<Student> Students = entityManager.createQuery("from Student").getResultList();
for (Iterator<Student> iterator = Students.iterator(); iterator.hasNext();) {
Student student = (Student) iterator.next();
System.out.println(student.getStudentName());
}
entityManager.getTransaction().commit();
} catch (Exception e) {
entityManager.getTransaction().rollback();
}
}
public void updateStudent(Long studentId, String studentName) {
try {
entityManager.getTransaction().begin();
Student student = (Student) entityManager.find(Student.class, studentId);
student.setStudentName(studentName);
entityManager.getTransaction().commit();
} catch (Exception e) {
entityManager.getTransaction().rollback();
}
}
public void deleteStudent(Long studentId) {
try {
entityManager.getTransaction().begin();
Student student = (Student) entityManager.find(Student.class, studentId);
entityManager.remove(student);
entityManager.getTransaction().commit();
} catch (Exception e) {
entityManager.getTransaction().rollback();
}
}
}
Output
After Sucessfully insertion Sumith Anoop After Sucessfully modification Sumith Honai Anoop Pavanai After Sucessfully deletion Sumith Honai