更改log4j日志级别而不重启服务器

目的：服务器运行时修改log4j的输出级别后，不需要重启服务器。

        项目上线了后，我们生产环境一般设置的输出级别都是INFO，但是有些问题不一定能通过INFO信息找到。如何能做到 动态的修改日志的级别，而且不用重启服务，对线上环境的影响减少到最小呢？

首先POM中加上这些依赖：

<properties>
<spring_version>3.2.2.RELEASE</spring_version>
</properties>

<dependencies>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.6.2</version>
</dependency>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.6.2</version>
</dependency>

<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
</dependency>

<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.16</version>
</dependency>

<!-- spring -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring_version}</version>
</dependency>

</dependencies>

然后在项目的web.xml中加上:

log4jConfigLocation/WEB-INF/classes/log4j.propertieslog4jRefreshInterval6000org.springframework.web.util.Log4jConfigListener

log4jRefreshInterval 的作用是6000表示 开一条watchdog线程每6秒扫描一下配置文件的变化; 

最后附上log4j properties：

#log4j.rootLogger = [ level ] , appenderName, appenderName, ...
log4j.rootLogger = ERROR, console, dailyFile
#level=INFO,all can be output
#console is set to be a ConsoleAppender
log4j.appender.console = org.apache.log4j.ConsoleAppender
#console have four patterns
#org.apache.log4j.HTMLLayout
#org.apache.log4j.PatternLayout
#org.apache.log4j.SimpleLayout
#org.apache.log4j.TTCCLayout

log4j.appender.console.layout = org.apache.log4j.PatternLayout
#define the output type
log4j.appender.console.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] %m%n
#file is set to output to a extra file
log4j.appender.dailyFile=org.apache.log4j.DailyRollingFileAppender
#the absolute route of the log4j file
#log4j.appender.dailyFile.File = /tmp/smarthome/base-web
log4j.appender.dailyFile.File = D:\\base-web.log
log4j.appender.dailyFile.Append=true
log4j.appender.dailyFile.layout=org.apache.log4j.PatternLayout
log4j.appender.dailyFile.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] %m%n
log4j.appender.dailyFile.Threshold=INFO
log4j.appender.dailyFile.DatePattern='.'yyyy-MM-dd'.log'

测试代码下载链接