In this source code example, we will demonstrate how to use the save() method in Spring Data JPA to save an entity.
Spring Data JPA simplifies the data access layer of applications by reducing boilerplate code. One of the commonly used methods provided by the Spring Data JPA's CrudRepository interface is save(). This method can be used to save an entity. If the entity already exists, it will update the existing one; otherwise, it will create a new entry in the database.In this example, we will use the Product entity to save into the MySQL database.
Maven Dependencies
First, you need to add the below dependencies to your Spring boot project:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<scope>runtime</scope>
</dependency>
Create Product Entity
Let's first create a Product entity that we are going to save into the database using the save() method:
package net.javaguides.springdatajpacourse.entity;
import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;
import jakarta.persistence.*;
import java.math.BigDecimal;
import java.util.Date;
@Entity
@Table(name="products")
public class Product {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@Column(name = "sku")
private String sku;
@Column(name = "name")
private String name;
@Column(name = "description")
private String description;
@Column(name = "price")
private BigDecimal price;
@Column(name = "image_url")
private String imageUrl;
@Column(name = "active")
private boolean active;
@Column(name = "date_created")
@CreationTimestamp
private Date dateCreated;
@Column(name = "last_updated")
@UpdateTimestamp
private Date lastUpdated;
// getter and setter methods
@Override
public String toString() {
return "Product{" +
"id=" + id +
", sku='" + sku + '\'' +
", name='" + name + '\'' +
", description='" + description + '\'' +
", price=" + price +
", imageUrl='" + imageUrl + '\'' +
", active=" + active +
", dateCreated=" + dateCreated +
", lastUpdated=" + lastUpdated +
'}';
}
}
ProductRepository
Let's create a ProductRepository that extends the JpaRepository interface:
import net.javaguides.springdatajpacourse.entity.Product;
import org.springframework.data.jpa.repository.JpaRepository;
public interface ProductRepository extends JpaRepository<Product, Long> {
}
Configure MySQL and Hibernate Properties
Let's use the MySQL database to store and retrieve the data in this example and we gonna use Hibernate properties to create and drop tables.
Open the application.properties file and add the following configuration to it:
spring.datasource.url=jdbc:mysql://localhost:3306/demo?useSSL=false
spring.datasource.username=root
spring.datasource.password=Mysql@123
spring.jpa.hibernate.ddl-auto = create-drop
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
Make sure that you will create a demo database before running the Spring boot application.
Also, change the MySQL username and password as per your MySQL installation on your machine.
Testing save() Method
Let's write a JUnit test to test saving Product entities into the MySQL database:
import net.javaguides.springdatajpacourse.entity.Product;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import java.math.BigDecimal;
import java.util.List;
@DataJpaTest
@AutoConfigureTestDatabase(replace= AutoConfigureTestDatabase.Replace.NONE)
class ProductRepositoryTest {
@Autowired
private ProductRepository productRepository;
@Test
void testSaveMethod() throws InterruptedException {
Product product = getProduct1();
// save product
productRepository.save(product);
}
protected Product getProduct1(){
Product product = new Product();
product.setName("product 1");
product.setDescription("product 1 desc");
product.setPrice(new BigDecimal(100));
product.setSku("product 1 sku");
product.setActive(true);
product.setImageUrl("product1.png");
return product;
}
}
We are using @DataJpaTest annotation to write a JUnit test ProductRepository save() method.
@AutoConfigureTestDatabase annotation is to disable embedded in-memory database support and enable MySQL database support.Output
Here is the output of the above JUnit test case we wrote for testing the save() method:
Hibernate:
insert
into
products
(active, date_created, description, image_url, last_updated, name, price, sku)
values
(?, ?, ?, ?, ?, ?, ?, ?)
Related Spring Data JPA Examples
- Spring Data JPA - save() Method Example
- Spring Data JPA - saveAll() Method Example
- Spring Data JPA - findById() Method Example
- Spring Data JPA - findAll() Method Example
- Spring Data JPA - count() Method Example
- Spring Data JPA - deleteById() Method Example
- Spring Data JPA - delete() Method Example
- Spring Data JPA - deleteAll() Method Example
- Spring Data JPA - Distinct Query Method Example
- Spring Data JPA - GreaterThan Query Method Example
- Spring Data JPA - LessThan Query Method Example
- Spring Data JPA - Containing Query Method Example
- Spring Data JPA - Like Query Method Example
- Spring Data JPA - Between Query Method Example
- Spring Data JPA - Date Range Between Query Method Example
- Spring Data JPA - In Clause Query Method Example