log4j升级到log4j2

1、导入依赖

log4j2应尽量使用同一版本，否则可能出现不兼容的情况

<!-- log4j2 start -->

<!-- log4j-1.2-api必须放在最前面，否则出错 -->

<dependency>

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

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

    <version>2.9.1</version>

</dependency>

<dependency>

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

    <artifactId>log4j-web</artifactId>

    <version>2.9.1</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->

<dependency>

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

    <artifactId>log4j-core</artifactId>

    <version>2.9.1</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api -->

<dependency>

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

    <artifactId>log4j-api</artifactId>

    <version>2.9.1</version>

</dependency>

<!-- log4j2 end -->

2、log4j.properties升级为log4j2.properties

log4j2支持log4j2.properties配置文件

status = warn

name = MyApp



#指定输出源‘类型’为控制台

appender.console.type = Console

appender.console.name = consoleLogDemo

appender.console.filter.threshold.type = ThresholdFilter

appender.console.filter.threshold.level = debug

appender.console.layout.type = PatternLayout

appender.console.layout.pattern = [%-5p] [%d{yyyy-MM-dd HH:mm:ss}] [%C{1}:%M:%L] %m%n

appender.console.target = System_out



appender.rolling.type = RollingFile

appender.rolling.name = fileLogDemo

appender.rolling.filter.threshold.type = ThresholdFilter

appender.rolling.filter.threshold.level = info

appender.rolling.layout.type = PatternLayout

appender.rolling.layout.pattern = [%-5p] [%d{yyyy-MM-dd HH:mm:ss}] [%C{1}:%M:%L] %m%n

appender.rolling.append = true

appender.rolling.fileName =/data/logs/workflow/web.log

appender.rolling.filePattern=/data/logs/wokflow/web.log.%d{yyyy-MM-dd}

appender.rolling.policies.type = Policies

appender.rolling.policies.time.type = TimeBasedTriggeringPolicy

appender.rolling.policies.time.interval = 2

appender.rolling.policies.time.modulate = true

appender.rolling.policies.size.type = SizeBasedTriggeringPolicy

appender.rolling.policies.size.size=100MB

appender.rolling.strategy.type = DefaultRolloverStrategy

appender.rolling.strategy.max = 5





logger.rolling.name = com.iqiyi

logger.rolling.level = info

logger.rolling.additivity = false

logger.rolling.appenderRef.rolling.ref = fileLogDemo



#指明根级日志的级别

rootLogger.level = info

#指定哪些appender输出源是根级日志的输出级别

rootLogger.appenderRef.consolelogdemo.ref = consoleLogDemo

rootLogger.appenderRef.filelogdemo.ref = fileLogDemo

参考文档：

[log4j2中的properties配置文件] http://www.360doc.com/content/18/0628/10/339365_766029208.shtml

[log4j 2.x 版本的 properties 配置] https://www.cnblogs.com/chensuqian/p/10419218.html

[升级log4j 2.x版本缓存异步化配置解读] https://www.iteye.com/blog/zl378837964-2359382

[旧web项目log4j日志升级至log4j2【从servlet2.x版本升级】] https://blog.csdn.net/leixingbang1989/article/details/86518061

3、log4j2.xml

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

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

    <Properties>

        <Property name="baseDir">log</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="trace" onMatch="ACCEPT" onMismatch="DENY"/>

            <PatternLayout pattern="%d %5p %c:%L - %m %throwable{}%n"/>

        </Console>

        <!--异步日志配置，指向配置引用AppenderRef-->

        <Async name="ASYNC" bufferSize="262144" includeLocation="true">

            <AppenderRef ref="RollingFile"/>

        </Async>

        <!--日志文件配置，filePattern为日志文件名称的格式-->

        <RollingFile name="RollingFile" fileName="${baseDir}/info.log" filePattern="${baseDir}/info.log.%d{yyyy-MM-dd}">

            <!--日志内容格式-->

            <PatternLayout pattern="%d %5p %c:%L - %m %throwable{separator( --> )}%n"/>

            <!--依据时间创建新的日志文件：1d-->

            <TimeBasedTriggeringPolicy interval="1"/>

            <DefaultRolloverStrategy>

                <!-- 在轮转时，删除7天之前的，命名符合规则的文件 -->

                <Delete basePath="${baseDir}">

                    <IfFileName glob="info.log.*"/>

                    <IfLastModified age="7d"/>

                </Delete>

            </DefaultRolloverStrategy>

        </RollingFile>

    </appenders>

    <!--然后定义logger，只有定义了logger并引入的appender，appender才会生效-->

    <loggers>

        <root level="INFO">

            <appender-ref ref="Console"/>

            <appender-ref ref="RollingFile"/>

        </root>

        <!--这里配置 过滤日志 -->

        <logger name="org.hibernate.validator" level="ERROR"/>

    </loggers>

</configuration>

4、修改web.xml

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

<web-app xmlns="http://java.sun.com/xml/ns/javaee"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

         version="2.5">

     <!--日志升级开始-->

    <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>

    <context-param>

        <param-name>log4jContextName</param-name>

        <param-value>myApplication</param-value>

    </context-param>

    <context-param>

        <param-name>log4jConfiguration</param-name>

        <param-value>classpath:log4j2.properties</param-value>

    </context-param>

    <!--日志升级结束-->

在web.xml中移除旧的log4j.property的配置

 <context-param>

      <param-name>log4jConfigLocation</param-name>

      <param-value>classpath:log4j.properties</param-value>

 </context-param>

5、log4j2测试

使用的LogManager.getLogger(Object.class)方式获取对象

加入测试类，并运行。如在项目磁盘目录下正常输出日志内容则说明log4j2添加成功：

public class TestLogger {

    private static final Logger log = LoggerFactory.getLogger(TestLogger.class);

    public static void main(String[] args) {

        int number=10;

        log.info("AAAAAAAAAAInfo : number is " + number);

        log.warn("AAAAAAAAAAAAAAAWarning : number is " + number);

        log.debug("AAAAAAAAADebug : number is " + number);

        log.error("AAAAAAAAAAAError : number is " + number);



    }

}