查看“Logback 的 access 模块”的源代码

https://www.bilibili.com/video/BV1iJ411H74S?p=31

=== 配置 Tomcat 使用 logback-access 记录日志 ===
本例使用：

* tomcat-8.5.31

* logback-access-1.1.7.jar
* logback-core-1.1.7.jar

logback-access 模块与 Servlet 容器（如 Tomcat 和 Jetty）集成，以提供 HTTP 访问日志功能。

可以使用 logback-access 模块来替换 tomcat 的访问日志。

# 将 logback-access.jar 与 logback-core.jar 复制到 $TOMCAT_HOME/lib/ 目录下
# 先注释掉原有关于 access log 的配置：<syntaxhighlight lang="xml">
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">

        <!-- Access log processes all example.
             Documentation at: /docs/config/valve.html
             Note: The pattern used is equivalent to using pattern="common" -->
        <!-- <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log" suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" /> -->

      </Host>
</syntaxhighlight>
# 修改 $TOMCAT_HOME/conf/server.xml 中的 Host 元素中添加：<syntaxhighlight lang="xml">
<Value className="ch.qos.logback.access.tomcat.LogbackValue"/>
</syntaxhighlight>变成：<syntaxhighlight lang="xml">
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">

        <!-- SingleSignOn valve, share authentication between web applications
             Documentation at: /docs/config/valve.html -->
        <!--
        <Valve className="org.apache.catalina.authenticator.SingleSignOn" />
        -->

        <!-- Access log processes all example.
             Documentation at: /docs/config/valve.html
             Note: The pattern used is equivalent to using pattern="common" -->
        <!-- <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log" suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" /> -->
          <Value className="ch.qos.logback.access.tomcat.LogbackValue"/>

      </Host>
</syntaxhighlight>
# Logback 默认会在 $TOMCAT_HOME/conf 下查找文件 logback-access.xml，所以要在 $TOMCAT_HOME/conf/ 下新建 logback-access.xml 文件并复制粘贴以下内容：<syntaxhighlight lang="xml">
<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <!-- always a good activate OnConsoleStatusListener -->
    <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener"/>

    <property name="LOG_DIR" value="${catalina.base}/logs"/>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${LOG_DIR}/access.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>access.%d{yyyy-MM-dd}.log.zip</fileNamePattern>
        </rollingPolicy>
        
        <encoder>
            <!-- 日志消息格式表达式 -->
            <pattern>%h %l %u [%t] "%r" %s %b "%i{Referer}</pattern>
            <!-- 访问日志的格式 -->
            <!-- <pattern>combined</pattern> -->
        </encoder>
    </appender>

    <appender-ref ref="FILE"/>
</configuration>
</syntaxhighlight>
# 官方配置说明：https://logback.qos.ch/access.html#configuration