This example presents the basic concept of using JPA CRUD in Spring.

The technologies used are :

– Spring 4.3.18
– H2 1.3
– Lombok 1.18
– JDK 1.8
– Maven 3.3.9

You can convert this example to an Eclipse IDE project by going to folder where is the pom.xml is, and use the command :

mvn eclipse:eclipse

Inspired from « Beginning Spring » Mert Caliskan, Kenan Sevindik, Rod Johnson (Foreword by), Jürgen Höller (Foreword by).

<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>javaspringexamples.springJPA</groupId>
	<artifactId>CRUD</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<properties>
		<maven.compiler.source>1.8</maven.compiler.source>
		<maven.compiler.target>1.8</maven.compiler.target>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-orm</artifactId>
			<version>4.3.18.RELEASE</version>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>4.3.18.RELEASE</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>4.3.1.Final</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-entitymanager</artifactId>
			<version>4.3.1.Final</version>
		</dependency>

		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<version>1.3.175</version>
		</dependency>
	</dependencies>
</project>

package javaspringexamples.springJPA.CRUD;

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

/**
 * 
 * @author mounir.sahrani@gmail.com
 *
 */
@Entity
public class Car {
	@Id
	@GeneratedValue
	private Long id;

	private String model;

	public String getModel() {
		return model;
	}

	public void setModel(String model) {
		this.model = model;
	}

	public Long getId() {
		return id;
	}
}

package javaspringexamples.springJPA.CRUD;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

/**
 * 
 * @author mounir.sahrani@gmail.com
 *
 */
public class Main {

	public static void main(String[] args) {
		EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("test-jpa");
		EntityManager entityManager = entityManagerFactory.createEntityManager();
		EntityTransaction transaction = entityManager.getTransaction();

		transaction.begin();
		// Creating entities
		Person person = new Person();
		person.setFirstName("Jabane");
		person.setLastName("KOLOBANE");
		Car car1 = new Car();
		car1.setModel("R4");
		Car car2 = new Car();
		car2.setModel("R6");
		// Add cars into person's collection
		person.getCars().add(car1);
		person.getCars().add(car2);
		// persisting entities
		entityManager.persist(person);
		System.out.println(person);
		//detaching cars
		long id = person.getId();
		person.getCars().clear();
		System.out.println(person);
		// Delete person
		entityManager.remove(person);
		// find displays null
		person = entityManager.find(Person.class, id);
		System.out.println("Find : " + person);
		// getReference throws javax.persistence.EntityNotFoundException
		person = entityManager.getReference(Person.class, id);
		System.out.println("getReference: " + person);

		transaction.commit();
		entityManager.close();
	}
}

package javaspringexamples.springJPA.CRUD;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;

/**
 * 
 * @author mounir.sahrani@gmail.com
 *
 */
@Entity
public class Person {

	@Id
	@GeneratedValue
	private Long id;

	private String firstName;

	private String lastName;

	@OneToMany(cascade = CascadeType.ALL)
	@JoinColumn(name = "person_id")
	private Set<Car> cars = new HashSet<Car>();

	public Long getId() {
		return id;
	}

	public String getFirstName() {
		return firstName;
	}

	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}

	public String getLastName() {
		return lastName;
	}

	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

	public Set<Car> getCars() {
		return cars;
	}

	@Override
	public String toString() {
		StringBuffer str = new StringBuffer(firstName + " " + lastName + " : ");
		for (Car c : cars)
			str.append("'" + c.getModel() + "' ");
		return str.toString();
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
    xmlns="http://java.sun.com/xml/ns/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">
    <persistence-unit name="test-jpa" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="hibernate.connection.driver_class" value="org.h2.Driver" />
            <property name="hibernate.connection.url" value="jdbc:h2:tcp://localhost/~/javaspringexamples" />
            <property name="hibernate.connection.username" value="sa" />
            <property name="hibernate.connection.password" value="" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect" />
            <property name="hibernate.hbm2ddl.auto" value="create" />
            <!-- property name="hibernate.hbm2ddl.auto" value="update" /-->
        </properties>
    </persistence-unit>
</persistence>

Get the sources of the example from the following GitHub url

Or Download a .zip file