6 Web Frameworks and ORM

Spring

@Bean

Each component in your Spring application is called a Bean. A class is annotated as being such with @bean, or another annotation wihch inherits from it. This is what tells the IOC/DI system inside Spring to treat the class as a component within the system.

@Component

This annotation tells spring that this class is a component and should be managed by the spring container.

@Configuration

Configuration classes are used to create beans, convetionally called AppConfig. if you want to have a bean dependent on another bean you must define it inside of a configuration class.

@Service

Service, unlike the other types of component offers no special functionality over @Component and is instead merely used to further show the intent of the class.

Springboot

@SpringBootApplication

@SpringBootApplication = @Configuration + @EnableAutoConfiguration + @ComponentScan

@EnableAutoConfiguration

It makes Spring guess the configuration based on the JAR files available on the classpath.  It can figure out what libraries you use and pre-configure their components without you lifting a finger.

SpringWebMVC

@Controller

@Controller marks the class as a web controller.

@RestController

@RestController = @Controller + @ResponseBody

@ResponseBody

The @ResponseBody is a utility annotation that tells Spring to automatically serialize return values of this classes methods into HTTP responses.

When building a JSON endpoint, this is an amazing way to "magically" convert your objects into JSON for easier consumption.

ORM

• ORM: Object Relational Mapping
• JPA: Jakarta Persistence API is a Jakarta EE application programming interface that describes the management of relational data in enterprise Java applications