Springboot에서 커스텀 필터 추가 방법

Filter를 구현하고 @Component 어노테이션을 붙여 등록한다.

import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
 
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
@Component
public class MyFilter implements Filter {
 
    @Override
    public void doFilter(ServletRequest request,
                        ServletResponse response,
                        FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
 
        System.out.println("Request URI is: " + req.getRequestURI());
        chain.doFilter(request, response);
        System.out.println("Response Status Code is: " + res.getStatus());
    }
}

 

Filter를 구현한 추상 클래스를 구현하고 @Component 를 붙여 등록한다. OncePerRequestFilter는 서블릿 당 한 번만 수행하도록 보장하는 필터 클래스이다.

import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;
 
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
@Component
public class MyFilter extends OncePerRequestFilter {
 
    @Override
    protected void doFilterInternal(HttpServletRequest httpServletRequest,
                                    HttpServletResponse httpServletResponse,
                                    FilterChain filterChain)
                                    throws ServletException, IOException {
 
        System.out.println("Request URI is: " + httpServletRequest.getRequestURI());
        filterChain.doFilter(httpServletRequest, httpServletResponse);
        System.out.println("Response Status Code is: " + httpServletResponse.getStatus());
    }
}

 

FilterRegistrationBean 유형의 @Bean을 등록한다. urlPattern을 등록하면서 특정 요청에만 필터를 사용하도록 할 수 있다.

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
 
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
public class MyFilter implements Filter {
 
    @Override
    public void doFilter(ServletRequest request,
                        ServletResponse response,
                        FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
 
        System.out.println("Request URI is: " + req.getRequestURI());
        chain.doFilter(request, response);
        System.out.println("Response Status Code is: " + res.getStatus());
    }
 
    @Bean
    public FilterRegistrationBean<MyFilter> filter()
    {
        FilterRegistrationBean<MyFilter> bean = new FilterRegistrationBean<>();
 
        bean.setFilter(new MyFilter());
        bean.addUrlPatterns("/execute/*");  // 또는 `setUrlPatterns()`를 사용합니다.
 
        return bean;
    }
}

 

@WebFilter 어노테이션을 붙여 등록한다. 이를 위해서는 @SpringbootApplication 어노테이션을 붙인 main에 @ServletComponentScan 어노테이션을 추가한다. 어노테이션의 옵션 중 urlPattern에 값을 넣어 특정 url 요청에만 필터가 동작하도록 할 수 있다.

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
@WebFilter(urlPatterns = "/execute/*")
public class FirstFilter implements Filter {
 
    @Override
    public void doFilter(ServletRequest request,
                        ServletResponse response,
                        FilterChain chain) throws IOException, ServletException
    {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
 
        System.out.println("Request URI is: " + req.getRequestURI());
        chain.doFilter(request, response);
        System.out.println("Response Status Code is: " + res.getStatus());
    }
}