将LOG4J 升级到LOG4J2

升级原因

log4j存在天然缺陷：

log4j采用同步输出模式，当遇到高并发&日志输出过多情况，可能导致线程阻塞，消耗时间过大
log4j无法实现自动删除按照日期产生的日志，现有项目都采用定时脚本删除日志。
通过调研，log4j2采用异步输出，并且能通过配置实现自动删除日志。

升级步骤

修改POM.XML

<log4j2.version>2.11.2</log4j2.version> 

       

<dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-core</artifactId>

            <version>${log4j2.version}</version>

        </dependency>

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-jcl</artifactId>

            <version>${log4j2.version}</version>

        </dependency>

         

        <dependency> 

            <groupId>org.apache.logging.log4j</groupId> 

            <artifactId>log4j-1.2-api</artifactId> 

            <version>${log4j2.version}</version> 

        </dependency> 

         

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-slf4j-impl</artifactId>

            <version>${log4j2.version}</version>

        </dependency>

 

 

<dependency>

        <groupId>commons-logging</groupId>

        <artifactId>commons-logging</artifactId>

        <version>1.2</version>

    </dependency>

排除下面的jar包

<exclusions>

                <exclusion>

                    <artifactId>slf4j-api</artifactId>

                    <groupId>org.slf4j</groupId>

                </exclusion>

                <exclusion>

                    <groupId>log4j</groupId>

                    <artifactId>log4j</artifactId>

                </exclusion>

                <exclusion>

                    <groupId>org.activiti</groupId>

                    <artifactId>activiti-bpmn-model</artifactId>

                </exclusion>

            </exclusions>

 

 

在启动项目时抛出错误：

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/E:/work/redxun/jsaas/src/main/webapp/WEB-INF/lib/activemq-all-5.10.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/E:/work/redxun/jsaas/src/main/webapp/WEB-INF/lib/log4j-slf4j-impl-2.11.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]

这种情况需要删除 activemq-all 中的slf4j 包。

 

在 resources 目录创建 log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>

<!-- 设置log4j2的自身log级别为warn -->

<!-- OFF > FATAL > ERROR > WARN > INFO > DEBUG > TRACE > ALL -->

<configuration status="error" monitorInterval="30">

    <properties>

        <property name="LOG_HOME">d:/logs</property>

        <property name="PATTERN_LAYOUT">[RX2]-%p-[%-d{yyyy-MM-dd HH:mm:ss}] [%t] %c{10}.%M(%L) | %m%n</property>

    </properties>

 

    <appenders>

        <console name="Console" target="SYSTEM_OUT">

            <PatternLayout pattern="${PATTERN_LAYOUT}"/>

        </console>

         

        <RollingFile name="RollingFileDebug" fileName="${LOG_HOME}/debug.log"

                     filePattern="${LOG_HOME}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log">

            <!--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" />

            <PatternLayout pattern="${PATTERN_LAYOUT}"/>

            <Policies>

                <TimeBasedTriggeringPolicy/>

                <SizeBasedTriggeringPolicy size="100 MB"/>

            </Policies>

        </RollingFile>

  

        <RollingFile name="RollingFileInfo" fileName="${LOG_HOME}/info.log"

                     filePattern="${LOG_HOME}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log">

            <!--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="WARN"  onMatch="ACCEPT" />

            <PatternLayout pattern="${PATTERN_LAYOUT}"/>

            <Policies>

                <TimeBasedTriggeringPolicy/>

                <SizeBasedTriggeringPolicy size="100 MB"/>

            </Policies>

        </RollingFile>

  

        <RollingFile name="RollingFileWarn" fileName="${LOG_HOME}/warn.log"

                     filePattern="${LOG_HOME}/$${date:yyyy-MM}/warn-%d{yyyy-MM-dd}-%i.log">

            <ThresholdFilter level="WARN" onMatch="ACCEPT" />

            <PatternLayout pattern="${PATTERN_LAYOUT}"/>

            <Policies>

                <TimeBasedTriggeringPolicy/>

                <SizeBasedTriggeringPolicy size="100 MB"/>

            </Policies>

        </RollingFile>

  

        <RollingFile name="RollingFileError" fileName="${LOG_HOME}/error.log"

                     filePattern="${LOG_HOME}/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log">

            <PatternLayout pattern="${PATTERN_LAYOUT}"/>

            <ThresholdFilter level="ERROR" onMatch="ACCEPT" />

            <Policies>

                <TimeBasedTriggeringPolicy/>

                <SizeBasedTriggeringPolicy size="100 MB"/>

            </Policies>

        </RollingFile>

  

    </appenders>

  

    <loggers>

        <!--

        <logger name="org.mybatis" level="INFO"></logger>

         -->

        <logger name="org.apache.activemq" level="INFO" >

            <appender-ref ref="Console"/>

            <appender-ref ref="RollingFileError"/>

        </logger>

        <root level="info">

            <appender-ref ref="Console"/>

            <appender-ref ref="RollingFileDebug"/>

            <appender-ref ref="RollingFileInfo"/>

            <appender-ref ref="RollingFileWarn"/>

            <appender-ref ref="RollingFileError"/>

        </root>

    </loggers>

  

</configuration>

在代码中使用log4j2

import org.apache.logging.log4j.LogManager;

import org.apache.logging.log4j.Logger;

 

 

Logger log = LogManager.getLogger("haha");

log.debug("debugger test");

log.warn("warn test");

log.error("err test");

log.info("info test");