Declaration

See equivalent in the Reactive stack

You can define controller beans by using a standard Spring bean definition in the Servlet’s WebApplicationContext. The @Controller stereotype allows for auto-detection, aligned with Spring general support for detecting @Component classes in the classpath and auto-registering bean definitions for them. It also acts as a stereotype for the annotated class, indicating its role as a web component.

To enable auto-detection of such @Controller beans, you can add component scanning to your Java configuration, as the following example shows:

Java
Kotlin

@Configuration
@ComponentScan("org.example.web")
public class WebConfig {

	// ...
}

@Configuration
@ComponentScan("org.example.web")
class WebConfig {

	// ...
}

The following example shows the XML configuration equivalent of the preceding example:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		https://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context
		https://www.springframework.org/schema/context/spring-context.xsd">

	<context:component-scan base-package="org.example.web"/>

	<!-- ... -->

</beans>

@RestController is a composed annotation that is itself meta-annotated with @Controller and @ResponseBody to indicate a controller whose every method inherits the type-level @ResponseBody annotation and, therefore, writes directly to the response body versus view resolution and rendering with an HTML template.

AOP Proxies

See equivalent in the Reactive stack

In some cases, you may need to decorate a controller with an AOP proxy at runtime. One example is if you choose to have @Transactional annotations directly on the controller. When this is the case, for controllers specifically, we recommend using class-based proxying. This is automatically the case with such annotations directly on the controller.

If the controller implements an interface, and needs AOP proxying, you may need to explicitly configure class-based proxying. For example, with @EnableTransactionManagement you can change to @EnableTransactionManagement(proxyTargetClass = true), and with <tx:annotation-driven/> you can change to <tx:annotation-driven proxy-target-class="true"/>.

Keep in mind that as of 6.0, with interface proxying, Spring MVC no longer detects controllers based solely on a type-level @RequestMapping annotation on the interface. Please, enable class based proxying, or otherwise the interface must also have an @Controller annotation.