Some experiences of using log4j in spring

Spring uses log4j in two ways.

1. No configuration is made in Web. xml.

Log4j. properties is stored in the root directory of classpath,

At this time, the generated log file does not have a relative path. if you write a relative path, it is generated under the root path of Tomcat installation.

2. Set in Web. xml.

<context-param><param-name>log4jConfigLocation</param-name><param-value>WEB-INF/classes/log4j.properties</param-value></context-param><context-param><param-name>webAppRootKey</param-name><param-value>myappfuse.root</param-value></context-param><listener><listener-class>org.springframework.web.util.Log4jConfigListener</listener-class></listener><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener>

Note that:

1) It must be written as follows:

<param-value>WEB-INF/classes/log4j.properties</param-value>

If it is written:

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

The file cannot be found.

2) It must be written as follows:

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

3)
Log4jconfiglistener must be defined in
Before contextloaderlistener, otherwise two log files will appear, one in the project path and the other in the Tomcat root path.
4) if not defined
<context-param><param-name>webAppRootKey</param-name><param-value>myappfuse.root</param-value></context-param>
The path in the log4j. properties file should be: # {webapp. Root} by default}
3. Different Levels are displayed in different files:
#log4j.logger.com.ibatis=DEBUGlog4j.logger.com.ibatis=OFFlog4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUGlog4j.logger.com.ibatis.common.jdbc.ScriptRunner=DEBUGlog4j.logger.com.ibatis.SQL Map.engine.impl.SQL MapClientDelegate=DEBUG#log4j.logger.java.sql.Connection=DEBUGlog4j.logger.java.sql.Connection=OFFlog4j.logger.java.sql.Statement=DEBUGlog4j.logger.java.sql.PreparedStatement=DEBUGlog4j.logger.java.sql.ResultSet=DEBUG#log4j.appender.R.File=${webapp.root}/WEB-INF/logs/myfuse.log #log4j.rootLogger=INFO,R#log4j.rootLogger=FATAL,Rlog4j.rootLogger=INFO,R,stdout,Elog4j.addivity.org.apache=truelog4j.appender.R=org.apache.log4j.DailyRollingFileAppender#log4j.appender.R.File=${webapp.root}/WEB-INF/logs/chplan_info1.loglog4j.appender.R.File=${myappfuse.root}/www/log/chplan_info.log#log4j.appender.R.DatePattern=yyyy-MM-dd'.log'# Keep one backup file  log4j.appender.R.layout=org.apache.log4j.PatternLayout#log4j.appender.R.layout.ConversionPattern= %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%nlog4j.appender.R.layout.ConversionPattern= %-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p]   %m%nlog4j.logger.E=error log4j.appender.E=org.apache.log4j.DailyRollingFileAppender log4j.appender.E.layout=org.apache.log4j.PatternLayout log4j.appender.E.layout.ConversionPattern=[%p] [%d{yyyy-MM-dd HH:mm:ss}]  [ Class = %C | Method = %M | Line = %L ] | %m |%n log4j.appender.E.datePattern='.'yyyy-MM-dd log4j.appender.E.Threshold=ERROR log4j.appender.E.append=true #log4j.appender.E.Encoding=GBK #log4j.appender.E.File=${webapp.root}/WEB-INF/logs/chplan_error.log log4j.appender.E.File=${myappfuse.root}/www/log/chplan_error.loglog4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.outlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n