log4配置

log4j 和 log4j2

方式一：log4j2.xml

添加 jar 包

     <!-- log4j-core -->
     <!--
     <dependency>
         <groupId>org.apache.logging.log4j</groupId>
         <artifactId>log4j-core</artifactId>
         <version>2.6.2</version>
     </dependency>

文件配置：

 <?xml version="1.0" encoding="UTF-8"?>
 <Configuration>
     <Appenders>
         <Console name="STDOUT" target="SYSTEM_OUT">
             <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/>
         </Console>
     </Appenders>
     <Loggers>
         <Logger name="com.opensymphony.xwork2" level="debug"/>
         <Logger name="org.apache.struts2" level="debug"/>
         <Root level="warn">
             <AppenderRef ref="STDOUT"/>
         </Root>
     </Loggers>
 </Configuration>

方式二：log4j.properties

添加 jar 包

     <!-- log4j -->
     <dependency>
         <groupId>log4j</groupId>
         <artifactId>log4j</artifactId>
         <version>1.2.17</version>
     </dependency>

文件配置:

### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### direct messages to file mylog.log ###
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c:/mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change 'info' to 'debug' ###

log4j.rootLogger=info, stdout