最详细的Log4J使用教程

（3）配置文件log4j.properties

  set log levels  log4j.rootLogger = debug,stdout,D,E 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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n log4j.appender.D = org.apache.log4j.DailyRollingFileAppender log4j.appender.D.File = F://logs/log.log log4j.appender.D.Append = true log4j.appender.D.Threshold = DEBUG log4j.appender.D.layout = org.apache.log4j.PatternLayout log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n log4j.appender.E = org.apache.log4j.DailyRollingFileAppender log4j.appender.E.File =F://logs/error.log log4j.appender.E.Append = true log4j.appender.E.Threshold = ERROR 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 set log levels  log4j.rootLogger = debug,stdout,D,E 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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n log4j.appender.D = org.apache.log4j.DailyRollingFileAppender log4j.appender.D.File = F://logs/log.log log4j.appender.D.Append = true log4j.appender.D.Threshold = DEBUG log4j.appender.D.layout = org.apache.log4j.PatternLayout log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n log4j.appender.E = org.apache.log4j.DailyRollingFileAppender log4j.appender.E.File =F://logs/error.log log4j.appender.E.Append = true log4j.appender.E.Threshold = ERROR 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

（4）web容器一来就初始化的servlet

Log4JInitServlet.java

package com.mucfc; import java.io.File; import java.io.IOException; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.BasicConfigurator; import org.apache.log4j.PropertyConfigurator; / * Servlet implementation class Log4JInitServlet */ @WebServlet("/Log4JInitServlet") public class Log4JInitServlet extends HttpServlet { private static final long serialVersionUID = 1L; / * @see HttpServlet#HttpServlet() */ public Log4JInitServlet() { super(); // TODO Auto-generated constructor stub  } / * @see Servlet#init(ServletConfig) */ public void init(ServletConfig config) throws ServletException { System.out.println("Log4JInitServlet 正在初始化 log4j日志设置信息"); String log4jLocation = config.getInitParameter("log4j-properties-location"); ServletContext sc = config.getServletContext(); if (log4jLocation == null) { System.err.println("* 没有 log4j-properties-location 初始化的文件, 所以使用 BasicConfigurator初始化"); BasicConfigurator.configure(); } else { String webAppPath = sc.getRealPath("/"); String log4jProp = webAppPath + log4jLocation; File yoMamaYesThisSaysYoMama = new File(log4jProp); if (yoMamaYesThisSaysYoMama.exists()) { System.out.println("使用: " + log4jProp+"初始化日志设置信息"); PropertyConfigurator.configure(log4jProp); } else { System.err.println("* " + log4jProp + " 文件没有找到， 所以使用 BasicConfigurator初始化"); BasicConfigurator.configure(); } } super.init(config); } / * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub  } / * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub  } }import java.io.File; import java.io.IOException; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.BasicConfigurator; import org.apache.log4j.PropertyConfigurator; / * Servlet implementation class Log4JInitServlet */ @WebServlet("/Log4JInitServlet") public class Log4JInitServlet extends HttpServlet { private static final long serialVersionUID = 1L; / * @see HttpServlet#HttpServlet() */ public Log4JInitServlet() { super(); // TODO Auto-generated constructor stub  } / * @see Servlet#init(ServletConfig) */ public void init(ServletConfig config) throws ServletException { System.out.println("Log4JInitServlet 正在初始化 log4j日志设置信息"); String log4jLocation = config.getInitParameter("log4j-properties-location"); ServletContext sc = config.getServletContext(); if (log4jLocation == null) { System.err.println("* 没有 log4j-properties-location 初始化的文件, 所以使用 BasicConfigurator初始化"); BasicConfigurator.configure(); } else { String webAppPath = sc.getRealPath("/"); String log4jProp = webAppPath + log4jLocation; File yoMamaYesThisSaysYoMama = new File(log4jProp); if (yoMamaYesThisSaysYoMama.exists()) { System.out.println("使用: " + log4jProp+"初始化日志设置信息"); PropertyConfigurator.configure(log4jProp); } else { System.err.println("* " + log4jProp + " 文件没有找到， 所以使用 BasicConfigurator初始化"); BasicConfigurator.configure(); } } super.init(config); } / * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub  } / * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub  } }

调用日志Log4JTestServlet,java

package com.mucfc; import java.io.IOException; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; / * Servlet implementation class Log4JTestServlet */ @WebServlet("/Log4JTestServlet") public class Log4JTestServlet extends HttpServlet { private static final long serialVersionUID = 1L; private static Logger logger = Logger.getLogger(Log4JTestServlet.class); / * @see HttpServlet#HttpServlet() */ public Log4JTestServlet() { super(); // TODO Auto-generated constructor stub  } / * @see Servlet#init(ServletConfig) */ public void init(ServletConfig config) throws ServletException { // TODO Auto-generated method stub  } / * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 记录debug级别的信息  logger.debug("This is debug message."); // 记录info级别的信息  logger.info("This is info message."); // 记录error级别的信息  logger.error("This is error message."); } / * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } } com.mucfc; import java.io.IOException; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; / * Servlet implementation class Log4JTestServlet */ @WebServlet("/Log4JTestServlet") public class Log4JTestServlet extends HttpServlet { private static final long serialVersionUID = 1L; private static Logger logger = Logger.getLogger(Log4JTestServlet.class); / * @see HttpServlet#HttpServlet() */ public Log4JTestServlet() { super(); // TODO Auto-generated constructor stub  } / * @see Servlet#init(ServletConfig) */ public void init(ServletConfig config) throws ServletException { // TODO Auto-generated method stub  } / * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 记录debug级别的信息  logger.debug("This is debug message."); // 记录info级别的信息  logger.info("This is info message."); // 记录error级别的信息  logger.error("This is error message."); } / * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } }

接下来就是运行了，来看看结果：

输出结果：

四、Spring中使用Log4j

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

 
      
      
    webAppRootKey  
    webapp.root   
      
    log4jConfigLocation  
    /WEB-INF/classes/log4j.properties   
      
      
    log4jRefreshInterval  
    3000   
      
    org.springframework.web.util.Log4jConfigListener   
     
   webAppRootKey  
   webapp.root   
     
   log4jConfigLocation  
   /WEB-INF/classes/log4j.properties   
     
     
   log4jRefreshInterval  
   3000   
     
   org.springframework.web.util.Log4jConfigListener 

整个内容如下：

 
    xml version="1.0" encoding="UTF-8"?>  
     
       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">  
     LogLearning  
       
     Log4JTestServlet  
     com.mucfc.Log4JTestServlet   
       
       
       
     Log4JTestServlet  
     /test   
       
       
     org.springframework.web.context.ContextLoaderListener   
       
     contextConfigLocation  
     classpath:applicationContext.xml   
       
       
     webAppRootKey  
     webapp.root   
       
     log4jConfigLocation  
     /WEB-INF/classes/log4j.properties   
       
       
     log4jRefreshInterval  
     3000   
       
     org.springframework.web.util.Log4jConfigListener  xml version="1.0" encoding="UTF-8"?>  
    
      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">  
    LogLearning  
      
    Log4JTestServlet  
    com.mucfc.Log4JTestServlet   
      
      
      
    Log4JTestServlet  
    /test   
      
      
    org.springframework.web.context.ContextLoaderListener   
      
    contextConfigLocation  
    classpath:applicationContext.xml   
      
      
    webAppRootKey  
    webapp.root   
      
    log4jConfigLocation  
    /WEB-INF/classes/log4j.properties   
      
      
    log4jRefreshInterval  
    3000   
      
    org.springframework.web.util.Log4jConfigListener  

 
     xml version="1.0" encoding="UTF-8"?>  
      
        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"> xml version="1.0" encoding="UTF-8"?>  
     
       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">