@Controller와 @RestController

Controller와 RestController의 차이점에 대해 한 번 알아보겠습니다.

우선 @Controller 의 애터테이션을 까보았습니다.

Controller.java

package org.springframework.stereotype;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.core.annotation.AliasFor;

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface Controller {

	/**
	 * The value may indicate a suggestion for a logical component name,
	 * to be turned into a Spring bean in case of an autodetected component.
	 * @return the suggested component name, if any (or empty String otherwise)
	 */
	@AliasFor(annotation = Component.class)
	String value() default "";

}

RestController.java

package org.springframework.web.bind.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.core.annotation.AliasFor;
import org.springframework.stereotype.Controller;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Controller
@ResponseBody
public @interface RestController {

	/**
	 * The value may indicate a suggestion for a logical component name,
	 * to be turned into a Spring bean in case of an autodetected component.
	 * @return the suggested component name, if any (or empty String otherwise)
	 * @since 4.0.1
	 */
	@AliasFor(annotation = Controller.class)
	String value() default "";

}

첫 번째로, Controller 애너테이션은 Component 애너테이션을 포함하고 있고, RestController 는 이 Controller 를 포함하고 있습니다.

두 번째로 RestController 는 ResponseBody 애너테이션을 포함하고 있고, Controller 는 포함하고 있지 않습니다.