slf4j를 이용한 로그남기기

학습 목표

1. slf4j와 logback을 스프링 프레임워크와 함께 사용할 수 있도록 설정할 수 있다.
2. 애플리케이션에서 Logger를 이용해 로그를 남길 수 있다.

---

핵심 개념

• SLF4J
• logback
• Logger

pom.xml 파일에서 다음 부분을 수정합니다.

<!-- Spring -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>${spring.version}</version>
</dependency>

<!-- 로깅 관련 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
        </dependency>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>1.7.25</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

resource폴더에 logback.xml 파일을 작성합니다.

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="30 seconds">
    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <Pattern>%d{HH:mm} %-5level %logger{36} - %msg%n</Pattern>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>/tmp/access.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>/tmp/access-%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>

        <encoder>
            <Pattern>%d{HH:mm} %-5level %logger{36} - %msg%n</Pattern>
        </encoder>
    </appender>

    <logger name="org.springframework" level="info"/>
    <logger name="kr.or.connect" level="debug"/>

    <root level="debug">
        <appender-ref ref="CONSOLE"/>
        <appender-ref ref="FILE"/>
    </root>
</configuration>

LogInterceptor.java를 아래와 같이 수정합니다.

 

package kr.or.connect.guestbook.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class LogInterceptor extends HandlerInterceptorAdapter{
	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			ModelAndView modelAndView) throws Exception {
//		System.out.println(handler.toString() + " 가 종료되었습니다.  " + modelAndView.getViewName() + "을 view로 사용합니다.");
		logger.debug("{} 가종료되었습니다. {} 를 view로 사용합니다.", handler.toString(), modelAndView.getViewName());
	}

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {
//		System.out.println(handler.toString() + " 를 호출했습니다.");
		logger.debug("{} 를 호출했습니다.", handler.toString());
		return true;
	}

	
}