[Spring] filter(javax.servlet.Filter)

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09. com/mvc/upgrade/common/filter/LogFilter (impl javax.servlet.Filter)

com.mvc.upgrade.common.filter패키지를 만들고 LogFilter클래스를 만들겠습니다.

LogFilter클래스를 만들때 javax.servlet.Filter 인터페이스를 상속받아주세요!

package com.mvc.upgrade.common.filter; import java.io.IOException; import javax.servlet.Filter; import

package com.mvc.upgrade.common.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LogFilter implements Filter {
	
	private Logger logger = LoggerFactory.getLogger(LogFilter.class);

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		
		HttpServletRequest req = (HttpServletRequest) request;
		
		String remoteAddr = req.getRemoteAddr();
		String uri = req.getRequestURI();
		String url = req.getRequestURL().toString();
		String queryString = req.getQueryString();
		String referer = req.getHeader("referer");
		String agent = req.getHeader("User-Agent");
		
		StringBuffer sb = new StringBuffer();
		sb.append("\n* remoteAddr : " + remoteAddr)
	      .append("\n* uri : " + uri)
		  .append("\n* url : " + url)
		  .append("\n* queryString : " + queryString)
		  .append("\n* referer : " + referer)
		  .append("\n* agent : " + agent)
		  .append("\n");
		
		logger.info("\nLOG Filter" + sb);
		
		chain.doFilter(req, response);
	}

	@Override
	public void destroy() {

	}

}​

javax.servlet.Filter인터페이스를 상속받으면 init(), doFilter(), destory() 3개의 메소드가 오버라이드 됩니다.

init()은 필터가 만들어질때 실행되고 destory()는 필터가 종료될때 실행되는 메소드인데 잠시 그냥 넘어가겠습니다.

필드로 org.slf4j.Logger를 import하고 객체를 만들어주세요.

​

​

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10. web.xml : filter

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://Java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">

  <!-- The definition of the Root Spring COntainer shared by all Servlet and Filters -->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/spring/appServlet/application-context.xml</param-value>
  </context-param>
  
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  
  <!-- Creates the Spring Container shared by all Servelts and Filters -->
  <servlet>
    <servlet-name>appServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  
  <!-- Processes application requests -->
  <servlet-mapping>
    <servlet-name>appServlet</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
  
  <!-- 서버 밖에서 존재. 요청되는거, 응답되는거 받는 역할 -->
  <filter>
    <filter-name>encodingFilter</filter-name>
    <!-- 패키지 : org.spirngframework.web.filter -->
    <!-- 클래스 : CharacterEncoding -->
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  
  <filter>
  	<filter-name>logFilter</filter-name>
  	<filter-class>com.mvc.upgrade.common.filter.LogFilter</filter-class>
  </filter>
  <filter-mapping>
  	<filter-name>logFilter</filter-name>
  	<url-pattern>/*</url-pattern>
  </filter-mapping>
  
</web-app>

이만큼 추가됩니다.

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이제 프로젝트를 실행시켜보면 콘솔창에 찍히는 내용이 있을겁니다.

String remoteAddr = req.getRemoteAddr();

ip주소 ( IPv6 형태 ) -> IPv4 형태로 나오게 하려면 localhost 대신 127.0.0.1로 요청하면됨

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String uri = req.getRequestURI();

http 요청 url 중에 queryString까지 반환. (context path) / URI = URL + URN (어떤 경로에 누가 있는지?)

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String url = req.getRequestURL().toString();

quertString을 제외한 경로(서블릿 포함) - protocol + servername + protnumber + serverpath

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String queryString = req.getQueryString();

quertString : 경로 뒤에 있는 요청 쿼리 문자열(K=V 형태)

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String referer = req.getHeader("referer");

이전페이지의 url(getHeader : 지정한 요청 헤더값을 문자열로 반환)

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String agent = req.getHeader("User-Agent");

사용자 정보(browser version, os 등)

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위의 내용들을 console창에 찍어보았지만 이러한 내용들을 log파일이나 db에 저장해서 기록으로 남길수도 있습니다.