[Spring Boot] request, response 로그 남기기1 - Console: 트러블슈팅

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문제 발생

api 중 파라미터를 필요로 하는 api에서 로깅을 할 경우 파라미터가 사라지는 이슈가 발생했다.

알고보니 httpServeltRequest를 읽는 것(getInputStream)은 일회성만 가능하다고 한다.

 

참고: https://leeyongjin.tistory.com/entry/request-response-logging

cf) 이전 포스트: https://jeongwoo.tistory.com/38

 

이전 포스트에서는 파라미터가 필요없는 api에 대해 request에 파라미터를 추가해서 날리고 테스트 했기 때문에 상관이 없었다.

하지만 실무에서 해당 이슈때문에 급하게 미봉책으로 수정한 코드를 기록으로 남긴다.

+ 다음에 시간이 되면 참고한 블로그를 따라해보든 해서 온전한 해결책을 찾아봐야겠다.

 

해결책

Spring-web에서 이미 구현해둔 ContentCachingRequestWrapper를 사용했다.

 

최종 코드

1. build.gradle

// HttpServletRequestWrapper
api 'org.springframework.boot:spring-boot-starter-web'

 

2. CachingResponseWrapper.java

cf) CachingRequestWrapper.java의 경우 ContentCachingRequestWrapper를 사용했기 때문에 쓰레기 코드가 되어 삭제했다.

 

package com.??.filter;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.output.TeeOutputStream;
import org.springframework.util.FastByteArrayOutputStream;

import javax.servlet.ServletOutputStream;
import javax.servlet.WriteListener;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import java.io.*;

@Slf4j
public class CachingResponseWrapper extends HttpServletResponseWrapper {

    private final FastByteArrayOutputStream content = new FastByteArrayOutputStream(1024);
    private ServletOutputStream outputStream;

    public CachingResponseWrapper(HttpServletResponse response) {
        super(response);
    }

    @Override
    public ServletOutputStream getOutputStream() throws IOException {
        if (this.outputStream == null) {
            this.outputStream = new CachingResponseWrapper.CachedServletOutputStream(getResponse().getOutputStream(), this.content);
        }
        return this.outputStream;
    }

    public InputStream getContentInputStream() {
        return this.content.getInputStream();
    }

    private class CachedServletOutputStream extends ServletOutputStream {

        private final TeeOutputStream targetStream;

        public CachedServletOutputStream(OutputStream one, OutputStream two) {
            targetStream = new TeeOutputStream(one, two);
        }

        @Override
        public void write(int arg) throws IOException {
            this.targetStream.write(arg);
        }

        @Override
        public void write(byte[] buf, int off, int len) throws IOException {
            this.targetStream.write(buf, off, len);
        }

        @Override
        public void flush() throws IOException {
            super.flush();
            this.targetStream.flush();
        }

        @Override
        public void close() throws IOException {
            super.close();
            this.targetStream.close();
        }

        @Override
        public boolean isReady() {
            return false;
        }

        @Override
        public void setWriteListener(WriteListener writeListener) {
            throw new UnsupportedOperationException("not support");
        }
    }
}

 

3. RequestResponseWrapperFilter.java

package com.??.filter;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;
import org.springframework.web.util.ContentCachingRequestWrapper;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@Component
public class RequestResponseWrapperFilter extends OncePerRequestFilter {

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {
        ContentCachingRequestWrapper wrappingRequest = new ContentCachingRequestWrapper(request);
        if (isAsyncDispatch(request)) {
            filterChain.doFilter(request, response);
        } else {
            filterChain.doFilter(wrappingRequest, new CachingResponseWrapper(response));
        }
    }
}

 

4. HttpLogInterceptor.java

package com.??.interceptor;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.??.filter.CachingResponseWrapper;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.util.ContentCachingRequestWrapper;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.io.StringWriter;

import java.net.URLDecoder;

@Slf4j
@Component
public class HttpLogInterceptor implements HandlerInterceptor {
    private final ObjectMapper objectMapper;

    public HttpLogInterceptor(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        if (request instanceof ContentCachingRequestWrapper) {
            log.info("uri: " + request.getRequestURI());
        }

        return true;
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {

        InputStream tmpIs = ((CachingResponseWrapper) response).getContentInputStream();
        StringWriter writer = new StringWriter();
        IOUtils.copy(tmpIs, writer, "UTF-8");
        String res = writer.toString();
        log.info("response - {}", res);
    }
}

 

5. WebMvcConfig.java

@Autowired로 HttpLogInterceptor httpLongInterceptor를 DI했던 것을 final로 리팩토링했다.

 

package com.??.config;

import com.??.interceptor.HttpLogInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
@ComponentScan(basePackages={"com.??.interceptor"})
public class WebMvcConfig implements WebMvcConfigurer {

    private final HttpLogInterceptor httpLogInterceptor;

    public WebMvcConfig(HttpLogInterceptor httpLogInterceptor) {
        this.httpLogInterceptor = httpLogInterceptor;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(httpLogInterceptor)
                .addPathPatterns("/**");
    }
}