Log4j简单配置

Log4j是一组强大的日志组件，在项目中时常需要用它提供一些信息，这两天学习了一下它的简单配置。

第一步，我们需要导入log4j-1.2.14.jar到lib目录下

第二步，在src下建立log4j.properties文件。添加如下内容

log4j.properties
log4j.rootLogger =INFO,stdout
log4j.logger.sedion=INFO,db
log4j.logger.W=WARN,W
log4j.logger.E=ERROR,E

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

#输出WARN级别日志
log4j.appender.W =org.apache.log4j.RollingFileAppender
log4j.appender.W.File =${catalina.home}/logs/Test/Test_W.log
log4j.appender.W.Append =true
log4j.appender.W.Threshold =WARN
log4j.appender.W.layout = org.apache.log4j.PatternLayout
log4j.appender.W.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n

#输出ERROR级别日志
log4j.appender.E = org.apache.log4j.RollingFileAppender
log4j.appender.E.File = ${catalina.home}/logs/Test/Test_E.log
log4j.appender.E.Append = true
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern =%-d{yyyy-MM-dd HH\:mm\:ss} [ %t\:%r ] - [ %p ] %m%n

#######################

# JDBC Appender

#######################
log4j.appender.db=org.apache.log4j.jdbc.JDBCAppender
log4j.appender.db.BufferSize=1
log4j.appender.db.driver=com.mysql.jdbc.Driver
log4j.appender.db.URL=jdbc:mysql://localhost:3306/test
log4j.appender.db.user=root
log4j.appender.db.password=123
log4j.appender.db.sql=insert into operate_log(class,method,createtime,loglevel,logmsg,username) values ("%C","%M","%d{yyyy-MM-dd HH\:mm\:ss}","%p","%m","%X{username}")
log4j.appender.db.layout=org.apache.log4j.PatternLayout

新建一个数据库test和一张日志表operate_log。

可以看到数据库中有个username动态字段，所以我们要写个过滤器

package config.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.apache.log4j.MDC;

public class Log4jFilter implements Filter
{
private final static int DEDAULT_USERID = 0;
public void destroy()
{

}

public void doFilter(ServletRequest req, ServletResponse rep,
FilterChain chain) throws IOException, ServletException
{
HttpServletRequest request = (HttpServletRequest)req;
String username = request.getParameter("username");

if(username == null)
{
MDC.put("username", DEDAULT_USERID);
}
else
{
System.out.println("登陆名--"+username);
MDC.put("username", username);
}

chain.doFilter(req, rep);
}

public void init(FilterConfig arg0) throws ServletException
{

}

}

然后需要在web.xml中进行log4j.properties和过滤器的配置.

复制代码

<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:log4j.properties</param-value>
</context-param>

<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>

<filter>
<filter-name>LogResFilter</filter-name>
<filter-class>config.filter.Log4jFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>LogResFilter</filter-name>
<url-pattern>*.do</url-pattern>
</filter-mapping>

第三步，至此我们配置已经全部完成，简单写个登陆来验证一下。

jsp页面很简单，代码便不列出来了.

写个登陆实现类.

package sedion.zhr.controller;

import java.util.List;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import sedion.zhr.beans.UserBean;
import sedion.zhr.service.iml.UserServiceIml;

@Controller
@RequestMapping("/action")
public class LoginController
{

private static final Logger log_w= Logger.getLogger("W");
private static final Logger log_e = Logger.getLogger("E");
private Log logger = LogFactory.getLog(this.getClass());

@Resource(name = "UserService")
private UserServiceIml serviceIml;

@RequestMapping("/login.do")
public String login(UserBean bean,HttpServletRequest request,HttpServletResponse response) throws Exception
{

List<UserBean> beans = this.serviceIml.finduser(new String[]{bean.getUsername(),bean.getPassword()});

if(!beans.isEmpty())
{
log_w.warn("登陆成功--");
logger.info("登陆成功");