Spring Mysql R2DBC Example

Vikas Verma
technical
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Introduction

You can find the details about R2DBC from the official site of spring and R2DBC.

What is R2DBC?

R2DBC stands for Reactive Relational Database Connectivity, a specification to integrate SQL databases using reactive drivers. Spring Data R2DBC applies familiar Spring abstractions and repository support for R2DBC. –Spring Data R2DBC

The official site for R2DBC is here

Versions and Dependencies

  • org.springframework.boot:2.5.6
  • org.projectlombok:lombok:1.18.22
  • org.springframework.boot:spring-boot-starter-data-r2dbc:2.5.6
  • org.springframework.boot:spring-boot-starter-webflux:2.5.6
  • dev.miku:r2dbc-mysql:0.8.2.RELEASE
  • mysql:mysql-connector-java:8.0.27

Maven Repositories -

  • https://oss.jfrog.org/artifactory/oss-snapshot-local/
  • https://repo1.maven.org/maven2

Implementations

Technical Stack

  • Spring-Boot
  • Spring-Webflux
  • R2DBC
  • MySQL
  • Gradle

Configure the dependencies

build.gradle

We will use MySQL as the database for our application. For that, we need to use a database driver. You can get the list of the available drivers here.

Along with that, we need the mysql-connect-java driver.

dev.miku:r2dbc-mysql
mysql:mysql-connector-java

Configure the database connection details

application.properties

The spring boot configuration for the r2dbc are as follows -

spring.r2dbc.url=r2dbc:mysql://localhost:3306
spring.r2dbc.name=testdb
spring.r2dbc.username=vikas
spring.r2dbc.password=vikas

Enable the R2DBC Repositories

*SpringReactiveApplication.java

You need to activate reactive relational repositories using R2DBC by using the annotation EnableR2dbcRepositories.

@SpringBootApplication
@EnableR2dbcRepositories
public class SpringReactiveApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringReactiveApplication.class, args);
	}
}

That’s all that required to connect the application to database using R2DBC.

Now you can create controller classes and services class to access the data as below -

Create and Entity class

ProductEntity.java

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
@Table("product")
public class ProductEntity {
  @Id
  private long id;
  private String name;
  private String description;
}

Create an repository class

ProductRepo.java

interface ProductRepo extends ReactiveCrudRepository<ProductEntity, Long> { }

Create Controller class

WebFluxDemoController.java

  @GetMapping("/product/{id}")
  public Mono<ProductEntity> findProduct(@PathVariable(name = "id") long id) {
    return productRepo.findById(id);
  }

References

https://spring.io/projects/spring-data-r2dbc

Github

https://github.com/vikasontech/spring-reactive