4.Spring中使用Log4j

转自：https://blog.csdn.net/luohai859/article/details/52250807

这里要实现web项目中利用Spring来使用Log4j

（1）接上面的工程，然后再导入Spring的包

（2）web.xml增加

 <!-- 设置根目录 -->
    <context-param>
        <param-name>webAppRootKey</param-name>
        <param-value>webapp.root</param-value>
    </context-param>    

    <context-param>
     <param-name>log4jConfigLocation</param-name>
     <param-value>/WEB-INF/classes/log4j.properties</param-value>
 </context-param>
 <!-- 3000表示 开一条watchdog线程每60秒扫描一下配置文件的变化;这样便于日志存放位置的改变 -->
 <context-param>
         <param-name>log4jRefreshInterval</param-name>
         <param-value>3000</param-value>
    </context-param>
 <listener>
     <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
 </listener>

整个内容如下：

 <?xml version="1.0" encoding="UTF-8"?>
 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://java.sun.com/xml/ns/javaee"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
     id="WebApp_ID" version="3.0">
     <display-name>LogLearning</display-name>  

     <servlet>
         <servlet-name>Log4JTestServlet</servlet-name>
         <servlet-class>com.mucfc.Log4JTestServlet</servlet-class>
     </servlet>  

     <!--用来启动 log4jConfigLocation的servlet -->
 <!--     <servlet>
         <servlet-name>Log4JInitServlet</servlet-name>
         <servlet-class>com.mucfc.Log4JInitServlet</servlet-class>
         <init-param>
             <param-name>log4j-properties-location</param-name>
             <param-value>/WEB-INF/classes/log4j.properties</param-value>
         </init-param>
         <load-on-startup>1</load-on-startup>
     </servlet>-->  

     <servlet-mapping>
         <servlet-name>Log4JTestServlet</servlet-name>
         <url-pattern>/test</url-pattern>
     </servlet-mapping>   

         <!-- Spring 容器加载 -->
     <listener>
         <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
     </listener>
     <context-param>
         <param-name>contextConfigLocation</param-name>
         <param-value>classpath:applicationContext.xml</param-value>
     </context-param>   

     <!-- 设置根目录 -->
     <context-param>
         <param-name>webAppRootKey</param-name>
         <param-value>webapp.root</param-value>
     </context-param>    

     <context-param>
         <param-name>log4jConfigLocation</param-name>
         <param-value>/WEB-INF/classes/log4j.properties</param-value>
     </context-param>
     <!-- 3000表示 开一条watchdog线程每60秒扫描一下配置文件的变化;这样便于日志存放位置的改变 -->
     <context-param>
          <param-name>log4jRefreshInterval</param-name>
          <param-value>3000</param-value>
     </context-param>
     <listener>
         <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
     </listener>   

 </web-app>

这里Log4JInitServlet.java就相当于没用到了。

（2）applicationContext.xml

没有内容：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="    

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.2.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop-3.2.xsd

http://www.springframework.org/schema/context

           http://www.springframework.org/schema/context/spring-context-3.2.xsd">
</beans>

（3）这样日志就跟随Spring窗口启动而启动了

程序一运行，就会自动把日志打印

log.log

error.log为空，因为它只打印error级别以上的信息

浏览器输入http://localhost:8080/LogLearning2/test

然后打开文件