log4j2在web中的使用

一、依赖的包

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

private static final Logger LOGGER = LoggerFactory.getLogger(UserController.class);

 <apache.log4j2.version>2.7</apache.log4j2.version>
    <slf4j.version>1.7.22</slf4j.version>
 <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>jcl-over-slf4j</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-slf4j-impl</artifactId>
      <version>${apache.log4j2.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-core</artifactId>
      <version>${apache.log4j2.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-api</artifactId>
      <version>${apache.log4j2.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-web</artifactId>
      <version>${apache.log4j2.version}</version>
    </dependency>

二、web.xml配置log4j2的监听器

<!--设置log4j的配置文件位置-->
  <context-param>
    <param-name>log4jConfigLocation</param-name>
    <param-value>classpath:log4j2.xml</param-value>
  </context-param>
 <listener>
    <listener-class>org.apache.logging.log4j.web.Log4jServletContextListener</listener-class>
  </listener>
  <filter>
    <filter-name>log4jServletFilter</filter-name>
    <filter-class>org.apache.logging.log4j.web.Log4jServletFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>log4jServletFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>INCLUDE</dispatcher>
    <dispatcher>ERROR</dispatcher>
  </filter-mapping>

三、如果项目是maven所建，把log4j2.xml放在根目录下

<?xml version="1.0" encoding="UTF-8"?>
<configuration monitorInterval="30" status="DEBUG">
  <Properties>
    <Property name="fileName">myLog.log</Property>
    <Property name="backupFilePatch">/Users/study-hello/spring-web/logs</Property>
  </Properties>
  <!--先定义所有的appender-->
  <appenders>
    <!--这个输出控制台的配置-->
    <Console name="Console" target="SYSTEM_OUT">
      <!--控制台只输出level及以上级别的信息（onMatch），其他的直接拒绝（onMismatch）-->
      <ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
      <!--这个都知道是输出日志的格式-->
      <PatternLayout charset="UTF-8"
        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%-5level] %-10C %M %L: %m%n"/>
    </Console>

    <RollingFile fileName="${backupFilePatch}/debug.log"
      filePattern="${backupFilePatch}/$${date:yyyy-MM}/%d{yyyy-MM-dd}.debug.log"
      name="RollingFileDebug">
      <Filters>
        <ThresholdFilter level="INFO" onMatch="DENY" onMismatch="NEUTRAL"/>
        <ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
      </Filters>
      <PatternLayout charset="UTF-8"
        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS z} [%-5level] %C %M %L: %m%n"/>
      <Policies>
        <TimeBasedTriggeringPolicy interval="1" modulate="true"/>    
      </Policies>
    </RollingFile>

    <RollingFile fileName="${backupFilePatch}/info.log"
      filePattern="${backupFilePatch}/$${date:yyyy-MM}/%d{yyyy-MM-dd}.info.log"
      name="RollingFileInfo">
      <Filters>
        <ThresholdFilter level="WARN" onMatch="DENY" onMismatch="NEUTRAL"/>
        <ThresholdFilter level="INFO" onMatch="ACCEPT" onMismatch="DENY"/>
      </Filters>
      <PatternLayout charset="UTF-8"
        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS z} [%-5level] %C %M %L: %m%n"/>
      <Policies>
        <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
      </Policies>
    </RollingFile>

    <RollingFile fileName="${backupFilePatch}/warn.log"
      filePattern="${backupFilePatch}/$${date:yyyy-MM}/%d{yyyy-MM-dd}.warn.log"
      name="RollingFileWarn">
      <Filters>
        <ThresholdFilter level="ERROR" onMatch="DENY" onMismatch="NEUTRAL"/>
        <ThresholdFilter level="WARN" onMatch="ACCEPT" onMismatch="DENY"/>
      </Filters>
      <!--  z 表示时区 -->
      <PatternLayout charset="UTF-8"
        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS z} [%-5level] %C %M %L: %m%n"/>
      <Policies>
        <TimeBasedTriggeringPolicy interval="1" modulate="true"/>  
      </Policies>
    </RollingFile>

    <RollingFile fileName="${backupFilePatch}/error.log"
      filePattern="${backupFilePatch}/$${date:yyyy-MM}/%d{yyyy-MM-dd}.error.log"
      name="RollingFileError">
      <ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/>
      <!--  z 表示时区 -->
      <PatternLayout charset="UTF-8"
        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS z} [%-5level] %C %M %L: %m%n"/>
      <Policies>
        <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
      </Policies>
    </RollingFile>
  </appenders>

  <!--然后定义logger，只有定义了logger并引入的appender，appender才会生效-->
  <loggers>
  
    <Logger level="DEBUG" name="com.ibatis">
      <AppenderRef ref="RollingFileDebug"/>
      <AppenderRef ref="RollingFileInfo"/>
      <AppenderRef ref="RollingFileWarn"/>
      <AppenderRef ref="RollingFileError"/>
    </Logger>
    
    <Root level="DEBUG">
      <!--AppenderRef：Root的子节点，用来指定该日志输出到哪个Appender. -->
      <AppenderRef ref="Console"/>
      <AppenderRef ref="RollingFileDebug"/>
      <AppenderRef ref="RollingFileInfo"/>
      <AppenderRef ref="RollingFileWarn"/>
      <AppenderRef ref="RollingFileError"/>
    </Root>
  </loggers>
</configuration>