spring中使用logback日志组件替换log4j

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.sjl.servlet.listener;
import java.io.FileInputStream;
import java.io.InputStream;

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 gladmustang
* @version 1.0
*/

public class LogbackConfigListener implements ServletContextListener {
private static final Logger logger = LoggerFactory.getLogger(LogbackConfigListener.class);

private static final String CONFIG_LOCATION = "logbackConfigLocation";

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 = "";
InputStream fi = null;

try {
if(logbackConfigLocation.startsWith("classpath:")) {
//使用类路径加载
String packagelocation = logbackConfigLocation.substring(logbackConfigLocation.indexOf(':')+1);
fi = this.getClass().getResourceAsStream("/"+ packagelocation);

} else {
//使用web根目录加载
fn = event.getServletContext().getRealPath(logbackConfigLocation);
fi = new FileInputStream(fn);
}

LoggerContext loggerContext = (LoggerContext)LoggerFactory.getILoggerFactory();
JoranConfigurator joranConfigurator = new JoranConfigurator();
joranConfigurator.setContext(loggerContext);
loggerContext.reset();
joranConfigurator.doConfigure(fi);

logger.debug("loaded slf4j configure file from {}", fn);
}
catch (JoranException e) {
logger.error("can not loading slf4j configure file from " + fn, e);

} catch (Exception e) {
e.printStackTrace();
}
}

public void contextDestroyed(ServletContextEvent event) {
}
}

在web.xml中加入(可以使用classpath或者web根路径方式)

<!--初始化日志配置文件 -->
<listener>
<listener-class>
com.sjl.servlet.listener.LogbackConfigListener
</listener-class>
</listener>
<context-param>
<param-name>logbackConfigLocation</param-name>
<param-value>classpath:config/logback.xml</param-value>
<!--      <param-value>WEB/INF/config/logback.xml</param-value>   -->
</context-param>

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。