[개념] AOP(관점지향프로그래밍)

AOP 소개
흩어진 코드를 한 곳으로 모아

 

예제

>>public @interface LogExecutionTime 생성

package org.springframework.samples.petclinic.aspect;

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

@Target(ElementType.METHOD) //메소드에다가 붙일거니까 타켓이 메소드
@Retention(RetentionPolicy.RUNTIME) //어노테이션을 사용한이 코드를 언제까지 유지할거냐
public @interface LogExecutionTime {
}

>>public class LogAspect 생성 

package org.springframework.samples.petclinic.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.util.StopWatch;


@Component //Spring bean만 Aspect가 될 수 있다
@Aspect
public class LogAspect {

    Logger logger = LoggerFactory.getLogger(LogAspect.class);

    //이 어노테이션주변으로 이런일들을 하라
    @Around("@annotaion(LogExecutionTime)")
    public Object logExecutionTime(ProceedingJoinPoint joinPoint) throws Throwable{

        StopWatch stopWatch = new StopWatch();
        stopWatch.start();

        Object proceed = joinPoint.proceed();

        stopWatch.stop();
        logger.info(stopWatch.prettyPrint());

        return proceed;
    }
}

>>아래와 같이 적용 

@Controller
class OwnerController {

	private static final String VIEWS_OWNER_CREATE_OR_UPDATE_FORM = "owners/createOrUpdateOwnerForm";

	private final OwnerRepository owners;

	private VisitRepository visits;

	public OwnerController(OwnerRepository clinicService, VisitRepository visits) {
		this.owners = clinicService;
		this.visits = visits;
	}

	@InitBinder
	public void setAllowedFields(WebDataBinder dataBinder) {
		dataBinder.setDisallowedFields("id");
	}

	@LogExecutionTime
	@GetMapping("/owners/new")
	public String initCreationForm(Map<String, Object> model) {
		Owner owner = new Owner();
		model.put("owner", owner);
		return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
	}
    @LogExecutionTime
	@PostMapping("/owners/new")
	public String processCreationForm(@Valid Owner owner, BindingResult result) {
		if (result.hasErrors()) {
			return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
		}
		else {
			this.owners.save(owner);
			return "redirect:/owners/" + owner.getId();
		}
	}
    @LogExecutionTime
	@GetMapping("/owners/find")
	public String initFindForm(Map<String, Object> model) {
		model.put("owner", new Owner());
		return "owners/findOwners";
	}

    @LogExecutionTime
	@GetMapping("/owners")
	public String processFindForm(Owner owner, BindingResult result, Map<String, Object> model) {

		// allow parameterless GET request for /owners to return all records
		if (owner.getLastName() == null) {
			owner.setLastName(""); // empty string signifies broadest possible search
		}

		// find owners by last name
		Collection<Owner> results = this.owners.findByLastName(owner.getLastName());
		if (results.isEmpty()) {
			// no owners found
			result.rejectValue("lastName", "notFound", "not found");
			return "owners/findOwners";
		}
		else if (results.size() == 1) {
			// 1 owner found
			owner = results.iterator().next();
			return "redirect:/owners/" + owner.getId();
		}
		else {
			// multiple owners found
			model.put("selections", results);
			return "owners/ownersList";
		}
	}

	@GetMapping("/owners/{ownerId}/edit")
	public String initUpdateOwnerForm(@PathVariable("ownerId") int ownerId, Model model) {
		Owner owner = this.owners.findById(ownerId);
		model.addAttribute(owner);
		return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
	}

	@PostMapping("/owners/{ownerId}/edit")
	public String processUpdateOwnerForm(@Valid Owner owner, BindingResult result,
			@PathVariable("ownerId") int ownerId) {
		if (result.hasErrors()) {
			return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
		}
		else {
			owner.setId(ownerId);
			this.owners.save(owner);
			return "redirect:/owners/{ownerId}";
		}
	}


	@GetMapping("/owners/{ownerId}")
	public ModelAndView showOwner(@PathVariable("ownerId") int ownerId) {
		ModelAndView mav = new ModelAndView("owners/ownerDetails");
		Owner owner = this.owners.findById(ownerId);
		for (Pet pet : owner.getPets()) {
			pet.setVisitsInternal(visits.findByPetId(pet.getId()));
		}
		mav.addObject(owner);
		return mav;
	}

}

 

구조

구조

출력되는 결과 

 

참조

https://drive.google.com/file/d/1Q8LGrUKzV_EX6MToQaynhv0CnPDCTgbM/view