log4j.properties样例

需要jar包

commons.logging-1.1.1.jar

log4j-1.2.15.jar

log4j.properties文件放到src或resources目录下

log4j.properties

#---- global logging configuration
#---- level: FATAL,ERROR,WARN,INFO,DEBUG
#---- appender: console, file, mail
### set log levels ###
log4j.rootLogger = INFO, console, file

### 输出到控制台 ###
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern =  %d{ABSOLUTE} %5p %c{1}:%L - %m%n

### 输出到日志文件 ###
log4j.appender.file = org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File = ${webName.root}/WEB-INF/logs/app.log
log4j.appender.file.DatePattern=_yyyyMMdd'.log'
#log4j.appender.file.Append = true
#log4j.appender.file.Threshold = INFO
log4j.appender.file.layout = org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern =%-d{yyyy-MM-dd HH\:mm\:ss}  [ %t\:%r ] - [ %p ]  %m%n

web.xml 用spring的 注意，要在配置spring前配置log4j

	<!-- log4j -->
	<context-param>
		<param-name>webAppRootKey</param-name>  
		<param-value>webName.root</param-value>
	</context-param>
	<context-param>
		<param-name>log4jConfigLocation</param-name>
		<param-value>classpath:log4j.properties</param-value>
	</context-param>
	<!-- log4j刷新时间毫秒 -->
	<context-param>
		<param-name>log4jRefreshInterval</param-name>
		<param-value>60000</param-value>
	</context-param>
	 
	<listener>
		<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
	</listener>
	
	<!-- Spring -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:applicationContext-*.xml</param-value>
	</context-param>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

不用spring的，需要配置个监听器，设置webAppRootKey

http://happyqing.iteye.com/blog/1416826

java使用

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

//静态
private static final Log log = LogFactory.getLog(MyClass.class);
log.info("log");

//非静态
private Log log = LogFactory.getLog(this.getClass().getName());
log.info("log"); 

maven依赖

<!-- log4j -->
<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-log4j12</artifactId>
	<version>1.7.5</version>
</dependency>
<dependency>
	<groupId>log4j</groupId>
	<artifactId>log4j</artifactId>
	<version>1.2.17</version>
</dependency>
<dependency>
	<groupId>commons-logging</groupId>
	<artifactId>commons-logging</artifactId>
	<version>1.1.1</version>
</dependency>