log4j的xml配置方式

一，原来一贯用的properties配置文件
log4j.properties

log4j.rootLogger = WARN, stdout
#, file, html

#----------------------------------------------------------------
# Console
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{1}:%L - %m%n

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

#----------------------------------------------------------------
# HTML
#log4j.appender.html = org.apache.log4j.FileAppender
#log4j.appender.html.File = d:/mylog.html
#log4j.appender.html.layout = org.apache.log4j.HTMLLayout



#----------------------------------------------------------------
# Package !!!
#log4j.logger.com.ying.dang.actions=DEBUG

二，今天在东洋人的要求下开始使用xml方式的配置文件
log4j.xml 比较典型

<?xml version="1.0" encoding="UTF-8"?>    
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
	<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d{ABSOLUTE} %5p %c{1}:%L - %m%n" />
		</layout>
	</appender>

	<appender name="file" class="org.apache.log4j.FileAppender">
		<param name="File" value="D:/test.log" />
		<param name="Append" value="true" />
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d{ABSOLUTE} %5p %c{1}:%L - %m%n" />
		</layout>
	</appender>

	<appender name="html" class="org.apache.log4j.FileAppender">
		<param name="Append" value="true" />
		<param name="File" value="D:/test.html" />
		<layout class="org.apache.log4j.HTMLLayout" />
	</appender>
	
	<appender name="daily" class="org.apache.log4j.DailyRollingFileAppender">     
		<param name="File" value="log/daily.log" />
		<param name="DatePattern" value="'daily.'yyyy-MM-dd'.log'" />
		<param name="Append" value="true" />
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d{ABSOLUTE} %5p %c{1}:%L - %m%n" />     
		</layout>
	</appender>

	<category name="cn.com.legendapl.spring.log" additivity="false">  
		<level value="DEBUG" />
		<appender-ref ref="stdout" />
	</category>

	<root>
		<level value="ERROR" />
		<appender-ref ref="stdout" />
		<appender-ref ref="file" />
		<appender-ref ref="html" />
	</root>
</log4j:configuration>

三，log4j的xml配置文件的树状结构如下所示，注意下图只显示了常用的部分。

xml declaration and dtd
            |
          log4j:configuration
            |
            +-- appender (name, class)
            |     |
            |     +-- param (name, value)
            |     +-- layout (class)
            |           |
            |           +-- param (name, value)
            +-- logger (name, additivity)
            |     |
            |     +-- level (class, value)
            |     |     |
            |     |     +-- param (name, value)
            |     +-- appender-ref (ref)
            +-- root
                  |
                  +-- param (name, class)
                  +-- level
                  |     |
                  |     +-- param (name, value)
                  +-- appender-ref (ref)

四，日志格式的含义

• %m 输出代码中指定的消息
• %p 输出优先级,即DEBUG,INFO,WARN,ERROR,FATAL 
• %r 输出自应用启动到输出该log信息耗费的毫秒数 
• %c 输出所属的类目,通常就是所在类的全名
• %t 输出产生该日志事件的线程名
• %n 输出一个回车换行符,Windows平台为"\r\n",Unix平台为"\n"
• %d 输出日志时间点的日期或时间,默认格式为ISO8601,也可以在其后指定格式

五，Log4j的初始化

public class Log4jInit extends HttpServlet {
     public void init() {
          String prefix = getServletContext().getRealPath("/");
          String file = getInitParameter("Log4j-init-file");
          if(file != null) {
             PropertyConfigurator.configure(prefix+file);
          }
      }
}

web.xml中配置一下

<servlet>
  <servlet-name>Log4j-init</servlet-name>
  <servlet-class>xx.xx.Log4jInit</servlet-class>

  <init-param>
    <param-name>Log4j-init-file</param-name>
    <param-value>WEB-INF/classes/Log4j.properties</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>

评论

2 楼 yingzhor 2012-05-23  

我还写过这样一篇博客啊。 我自己都不记得了。

1 楼 wait8712 2012-05-23  

配置的太多了，还是properties配置文件比较好用，只是你的功能太少了，呵呵