Log4j的使用

LOG4J安装配置全部过程。

0、首先当然要下载log4j.jar了
下载地址:http://logging.apache.org/log4j/1.2/download.html
我下载的是log4j-1.2.15.jar

1、新建Web Project

工程名：log4j (自己定义)



2、给工程添加Log4j
从0步下载的文件中找到log4j-1.2.15.jar文件，将其添加到工程的lib目录下。这步很简单的，但要确定jar包添加到了工程的构建路径。



3、创建并配置 log4j.properties文件
在src源文件目录下添加log4j.properties文件。
编辑文件内容：

#Console config
#OFF、FATAL、ERROR、WARN、INFO、DEBUG、ALL
#log4j.rootLogger=error, stdout, R
#log4j.appender.stdout=org.apache.log4j.ConsoleAppender
#log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#log4j.appender.stdout.layout.ConversionPattern=<%d>{yyyy MMM dd HH:mm:ss,SSS} <%-5p> <%c> <%t> - %m(%F:%M:%L)%n

#log4j.appender.R=org.apache.log4j.DailyRollingFileAppender
#log4j.appender.R.File=f:\\qc.log
#log4j.appender.R.layout=org.apache.log4j.PatternLayout
#log4j.appender.R.layout.ConversionPattern=%d-[TS] %p %t %c - %m%n

log4j.rootLogger=DEBUG,CONSOLE
#,A1,im
log4j.addivity.org.apache=true

# 应用于控制台

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.Threshold=DEBUG
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m %n
#log4j.appender.CONSOLE.layout.ConversionPattern=[start]%d{DATE}[DATE]%n%p[PRIORITY]%n%x[NDC]%n%t[THREAD] n%c[CATEGORY]%n%m[MESSAGE]%n%n

#应用于文件

log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=f:\\file.log
log4j.appender.FILE.Append=false
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n
# Use this layout for LogFactor 5 analysis

# 应用于文件回滚
log4j.appender.ROLLING_FILE=org.apache.log4j.RollingFileAppender
log4j.appender.ROLLING_FILE.Threshold=ERROR
log4j.appender.ROLLING_FILE.File=f:\\rolling.log
#文件位置,也可以用变量${java.home}、rolling.log
log4j.appender.ROLLING_FILE.Append=true      
#true:添加   false:覆盖
log4j.appender.ROLLING_FILE.MaxFileSize=10KB  
#文件最大尺寸
log4j.appender.ROLLING_FILE.MaxBackupIndex=1  
#备份数
log4j.appender.ROLLING_FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.ROLLING_FILE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n


#应用于socket
#log4j.appender.SOCKET=org.apache.log4j.RollingFileAppender
#log4j.appender.SOCKET.RemoteHost=localhost
#log4j.appender.SOCKET.Port=5001
#log4j.appender.SOCKET.LocationInfo=true
# Set up for Log Facter 5
#log4j.appender.SOCKET.layout=org.apache.log4j.PatternLayout
#log4j.appender.SOCET.layout.ConversionPattern=[start]%d{DATE}[DATE]%n%p[PRIORITY]%n%x[NDC]%n%t[THREAD]%n%c[CATEGORY]%n%m[MESSAGE]%n%n


# Log Factor 5 Appender
#log4j.appender.LF5_APPENDER=org.apache.log4j.lf5.LF5Appender
#log4j.appender.LF5_APPENDER.MaxNumberOfRecords=2000

# 发送日志给邮件
# log4j.appender.MAIL=org.apache.log4j.net.SMTPAppender
# log4j.appender.MAIL.Threshold=FATAL
# log4j.appender.MAIL.BufferSize=10
# log4j.appender.MAIL.From=[e-mail]
# log4j.appender.MAIL.SMTPHost=www.wusetu.com
# log4j.appender.MAIL.Subject=Log4J Message
# log4j.appender.MAIL.To=[e-mail]
# log4j.appender.MAIL.layout=org.apache.log4j.PatternLayout
# log4j.appender.MAIL.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n

# 用于数据库
#log4j.appender.DATABASE=org.apache.log4j.jdbc.JDBCAppender
#log4j.appender.DATABASE.URL=jdbc:mysql://localhost:3306/test
#log4j.appender.DATABASE.driver=com.mysql.jdbc.Driver
#log4j.appender.DATABASE.user=root
#log4j.appender.DATABASE.password=
#log4j.appender.DATABASE.sql=INSERT INTO LOG4J (Message) VALUES ('[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n')
#log4j.appender.DATABASE.layout=org.apache.log4j.PatternLayout
#log4j.appender.DATABASE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n

log4j.appender.A1=org.apache.log4j.DailyRollingFileAppender
log4j.appender.A1.File=SampleMessages.log4j
log4j.appender.A1.DatePattern=yyyyMMdd-HH'.log4j'
log4j.appender.A1.layout=org.apache.log4j.xml.XMLLayout

#自定义Appender
#log4j.appender.im = net.cybercorlin.util.logger.appender.IMAppender
#log4j.appender.im.host = mail.cybercorlin.net
#log4j.appender.im.username = username
#log4j.appender.im.password = password
#log4j.appender.im.recipient = [e-mail]
#log4j.appender.im.layout=org.apache.log4j.PatternLayout
#log4j.appender.im.layout.ConversionPattern =[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n


4、配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
     xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   <welcome-file-list>
     <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
  
   <servlet>  
     <servlet-name>log4j-init</servlet-name>  
     <servlet-class>test.Log4jInit</servlet-class>
     <init-param>
         <param-name>log4j</param-name>
         <param-value>WEB-INF/classes/log4j.properties</param-value>
     </init-param>  
     <load-on-startup>1</load-on-startup>
   </servlet>

</web-app>


5、创建初始化Log4jInit.java

package test;

import org.apache.log4j.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
    
@SuppressWarnings("serial")
public class Log4jInit extends HttpServlet {  
       public void init() {
             String prefix =getServletContext().getRealPath("/");
             String file = getInitParameter("log4j");//配置文件位置
             if(file != null) {  
                 PropertyConfigurator.configure(prefix+file);  
             }  
       }

       public void doGet(HttpServletRequest req, HttpServletResponse res)
     {     }
}

6、至此，log4j配置成功。在项目中就可以正常引用了。使用方法如下：

package test;

import org.apache.log4j.Logger;

import com.sun.org.apache.commons.logging.Log;
import com.sun.org.apache.commons.logging.LogFactory;

public class Log4jTest {
     private static Logger log = Logger.getLogger(Log4jTest.class);
     public void test() {
         log.debug("debug");
         log.trace("trace");
         log.debug("befor say hi");
        
        
         log.info("info");
         log.warn("warn");
         log.fatal("fatal");
         log.error("error");
     }
}


注：以上配置的是使用控制台打印日志信息的方式。
例如：上例将在控制台打印如下：

[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] DEBUG test.Log4jTest   - debug
[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] DEBUG test.Log4jTest   - befor say hi
[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] INFO   test.Log4jTest   - info
[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] WARN   test.Log4jTest   - warn
[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] FATAL test.Log4jTest   - fatal
[framework] 2008-07-10 09:37:02,203 - test.Log4jTest -0     [http-8081-1] ERROR test.Log4jTest   - error