[스프링부트]필터, 인터셉터, AOP

필터

예제

import java.io.IOException;

public class AuthenticationFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse) servletResponse;
        HttpSession session = req.getSession();

        User sessionUser = (User) session.getAttribute("sessionUser");
        if (sessionUser == null) {
            resp.sendRedirect("/login-form");
        }else {
            filterChain.doFilter(servletRequest, servletResponse);
        }
    }
}

import com.metacoding.authblog._core.filter.AuthenticationFilter;
import com.metacoding.authblog._core.filter.MerongFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FilterConfig {

        @Bean // 빈으로 등록하면 리턴값이 IoC 등록
        public FilterRegistrationBean addAuthFilter() {
            FilterRegistrationBean rg = new FilterRegistrationBean();
            rg.setFilter(new AuthenticationFilter()); // 필터를 등록
            rg.addUrlPatterns("/board/*");  // 필터를 실행할 uri 패턴
            rg.addUrlPatterns("/user/*");
            rg.setOrder(1); // filter의 실행 순서
            return rg;
        }
  }

인터셉터

예제

public class LoggingInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        System.out.println("Before handling request: " + request.getRequestURI());
        return true; // true면 다음 단계 진행
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
        System.out.println("After handling request: " + request.getRequestURI());
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        System.out.println("Request completed");
    }
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoggingInterceptor()).addPathPatterns("/**");
    }
}

AOP

예제

@Aspect
@Component
public class LoggingAspect {
    @Before("execution(* com.example.service.*.*(..))")
    public void logBefore(JoinPoint joinPoint) {
        System.out.println("Before method: " + joinPoint.getSignature().getName());
    }

    @After("execution(* com.example.service.*.*(..))")
    public void logAfter(JoinPoint joinPoint) {
        System.out.println("After method: " + joinPoint.getSignature().getName());
    }
}