logback比log4j的强大之处，请到logback的主页去看，我就不啰嗦了，你懂、或者不懂，logback就在那里，无比强大，傲视绝伦。

复制log4j-over-slf4j.jar,logback-classic.jar,logback-core.jar,jcl-over-slf4j.jar到lib目录，删除原有的log4j.jar。

创建一个新类

package com.boaotech.util;  import javax.servlet.ServletContextEvent;  import javax.servlet.ServletContextListener;  import org.slf4j.Logger;  import org.slf4j.LoggerFactory;  import ch.qos.logback.classic.LoggerContext;  import ch.qos.logback.classic.joran.JoranConfigurator;  import ch.qos.logback.core.joran.spi.JoranException;  /**  * @author Kiven Lee  * @version 1.0  */  public class LogbackConfigListener implements ServletContextListener {      private static final Logger logger = LoggerFactory.getLogger(LogbackConfigListener.class);           private static final String CONFIG_LOCATION = "logbackConfigLocation";      @Override      public void contextInitialized(ServletContextEvent event) {          //从web.xml中加载指定文件名的日志配置文件          String logbackConfigLocation = event.getServletContext().getInitParameter(CONFIG_LOCATION);          String fn = event.getServletContext().getRealPath(logbackConfigLocation);          try {              LoggerContext loggerContext = (LoggerContext)LoggerFactory.getILoggerFactory();              loggerContext.reset();              JoranConfigurator joranConfigurator = new JoranConfigurator();              joranConfigurator.setContext(loggerContext);              joranConfigurator.doConfigure(fn);              logger.debug("loaded slf4j configure file from {}", fn);          }          catch (JoranException e) {              logger.error("can loading slf4j configure file from " + fn, e);          }      }      @Override      public void contextDestroyed(ServletContextEvent event) {      }  }

在web.xml中加入

       
           
     
                 com.boaotech.util.LogbackConfigListener       
        
       
           
     
      logbackConfigLocation
            
     
      WEB-INF/logback.xml
        
    

最后，在WEB-INF下新建logback.xml配置，配置请参考logback帮助手册。

经过这样的配置后，应用中所有使用log4j,common-logger的jar，均可正常通过logback实现日志输出。