Spring MVC 集成 Logback

• 引用slf4j和logback的依赖，尤其是logback-ext-spring，是Logback对于Spring的扩展：

<dependency>
    <groupId>org.slf4jgroupId>
    <artifactId>slf4j-apiartifactId>
    <version>${slf4j.version}version>
dependency>
<dependency>
    <groupId>ch.qos.logbackgroupId>
    <artifactId>logback-classicartifactId>
    <version>${logback.version}version>
dependency>
<dependency>
    <groupId>ch.qos.logbackgroupId>
    <artifactId>logback-coreartifactId>
    <version>${logback.version}version>
dependency>
<dependency>
    <groupId>org.logback-extensionsgroupId>
    <artifactId>logback-ext-springartifactId>
    <version>${logback-ext-spring.version}version>
dependency>

• 定义Listener，作用是在项目启动时初始化Logback组件：

import ch.qos.logback.ext.spring.web.WebLogbackConfigurer;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class LogbackListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        // 注入系统变量，可以在logback.xml中引用
        System.setProperty("customSystemProperty", "xxx");

        WebLogbackConfigurer.initLogging(sce.getServletContext());
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        WebLogbackConfigurer.shutdownLogging(sce.getServletContext());
    }
}

• 在web.xml中声明LogbackListener，可指定logback.xml文件的路径：

<context-param>
    <param-name>logbackConfigLocationparam-name>
    <param-value>classpath:logback.xmlparam-value>
context-param>

<listener>
    <listener-class>com.yjy.listener.LogbackListenerlistener-class>
listener>

• 自定义logback.xml，声明日志格式、存放路径等：

<configuration>
    <property name="LOG_HOME" value="/export/logs/spring-framework-demo/" />
    <property name="APP_NAME" value="spring-framework-demo" />

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            
            <pattern>${APP_NAME}-${customSystemProperty}: %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %p - %c %method %m%npattern>
        encoder>
    appender>
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}${APP_NAME}.%d{yyyy-MM-dd}.log.gzFileNamePattern>
            
            <MaxHistory>30MaxHistory>
        rollingPolicy>
        <encoder>
            <pattern>${APP_NAME}: %d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %p - %c %method %m%npattern>
        encoder>
    appender>

    <root>
        <level value="INFO" />
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    root>
configuration>