log4j

日志是应用软件中不可缺少的部分，Apache的开源项目log4j是一个功能强大的日志组件,提供方便的日志记录。

1.maven配置

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

2.web.xml配置

        <context-param>   
    	　　<param-name>log4jConfigLocation</param-name>   
    	　　<param-value>classpath:/log4j/log4j.xml</param-value>   
	</context-param>   
	<listener>   
	    <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>   
	</listener>

3.log4j.xml配置

<?xml version="1.0" encoding="UTF-8"?>       
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">       
          
<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/' >       
          
    <appender name="myConsole" class="org.apache.log4j.ConsoleAppender">       
        <layout class="org.apache.log4j.PatternLayout">       
            <param name="ConversionPattern"          
                value="[%d{dd HH:mm:ss,SSS} %-5p] [%t] %c{2} - %m%n" />       
        </layout>       
        <!-- 过滤器设置输出的级别  -->
        <filter class="org.apache.log4j.varia.LevelRangeFilter">       
            <param name="levelMin" value="debug" />       
            <param name="levelMax" value="warn" />       
            <param name="AcceptOnMatch" value="true" />       
        </filter>       
    </appender>   
    
    <appender name="myFile" class="org.apache.log4j.RollingFileAppender">          
        <param name="File" value="${catalina.home}/logs/tomcat_output_errorInfo.log" /><!-- 设置日志输出文件名 errorInfo-->       
        <!-- 设置是否在重新启动服务时，在原有日志的基础添加新日志 -->       
        <param name="Append" value="false" />       
        <param name="MaxBackupIndex" value="10" />       
        <layout class="org.apache.log4j.PatternLayout">       
            <param name="ConversionPattern" value="%p (%c:%L)- %m%n" />       
        </layout>       
    </appender>       
         
    <appender name="activexAppender" class="org.apache.log4j.DailyRollingFileAppender">       
        <param name="File" value="${catalina.home}/logs/tomcat_output_sqlInfo.log" /><!-- 设置日志输出文件名 sqlInfo-->         
        <param name="DatePattern" value="'.'yyyy-MM-dd'.log'" />         
        <layout class="org.apache.log4j.PatternLayout">       
        	<param name="ConversionPattern" value="[%d{MMdd HH:mm:ss SSS} %-5p] [%t] %c{3} - %m%n" />       
        </layout>         
    </appender>       
          
    <!-- 指定logger的设置，additivity指示是否遵循缺省的继承机制-->       
    <logger name="com.online" additivity="false">    
        <appender-ref ref="activexAppender" />         
    </logger>  
	
    <!-- 根logger的设置-->       
    <root>       
        <priority value ="debug"/>       
        <appender-ref ref="myConsole"/>       
        <appender-ref ref="myFile"/>         
    </root>       
</log4j:configuration>  

4.tomcat logs 查看日志