struts2+spring+mybatis入门教程五之配置log4j_struts log4j需要初始化吗?-优快云博客

本文详细介绍了如何在Java Web项目中配置Log4j日志框架，包括必要的jar包引入、日志级别设置、输出路径配置及初始化过程。通过具体步骤和代码示例，帮助读者快速上手。

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（1）将javax.servlet_1.0.0.0_2-5.jar拷贝到web-inf/lib下。

（2）在web-inf根目录下新建文件log4j.properties，配置日志输出级别、日志路径等信息。log4j.properties代码：

# debug<info<warn<error
log4j.rootLogger=debug, LOGFILE
#log4j.debug=true

# Set the enterprise logger category to FATAL and its only appender to CONSOLE.
#设置包日志输出级别
#log4j.logger.com.xy6=INFO, CONSOLE

# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
#输出到控制台
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=INFO
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d %p [%c] - <%m>%n

#输出到文件
log4j.appender.LOGFILE=org.apache.log4j.RollingFileAppender
log4j.appender.LOGFILE.File=${webappRoot}/log/AllLog.log
log4j.appender.LOGFILE.MaxFileSize=10000KB
log4j.appender.LOGFILE.MaxBackupIndex=1000
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] %m%n

#mybatis显示SQL语句日志配置
log4j.logger.com.ibatis=DEBUG
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUG
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=DEBUG
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=DEBUG
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

（3）在web根目录下新建文件夹log，作为日志文件输出的根目录。

（4）在com.xy6下新建log4j初始化类Log4jInitServlet.java，初始化log4j配置文件中日志路径中的参数webappRoot，输出应用的磁盘路径。若log4j.properties中日志输出路径为固定值如E:\j2ee\workspace\SSM\web\log，则无需再写该类进行初始化。Log4jInitServlet.java代码：

package com.xy6;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import org.apache.log4j.PropertyConfigurator;

public class Log4jInitServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	public void init() throws ServletException {
		System.out.println("---path:"+getServletContext().getRealPath("/"));
		System.setProperty("webappRoot", getServletContext().getRealPath("/"));
		PropertyConfigurator.configure(getServletContext().getRealPath("/")
				+ getInitParameter("configfile"));
	}
}

（5）修改web.xml，配置log4j配置文件路径及初始化类。web.xml代码：

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
	<display-name>SSM</display-name>

	<welcome-file-list>
		<welcome-file>/demo/demo.jsp</welcome-file>
	</welcome-file-list>

	<filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/spring.xml</param-value>
	</context-param>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

    <servlet>
		<servlet-name>log4j config file</servlet-name>
		<servlet-class>com.xy6.Log4jInitServlet</servlet-class>
		<init-param>
			<param-name>configfile</param-name>
			<param-value>/WEB-INF/log4j.properties</param-value>
		</init-param>

		<load-on-startup>1</load-on-startup>
	</servlet>

</web-app>

（6）修改DemoAction.java，测试日志文件是否正确输出。DemoAction.java代码：

package com.xy6;

import java.util.List;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;

import com.opensymphony.xwork2.ActionSupport;

public class DemoAction extends ActionSupport {

	private static final long serialVersionUID = 1L;
	private final Logger logger = Logger.getLogger(DemoAction.class.getName());

	@Autowired
	private DemoDao demoDao;

	public String execute(){
		DemoHelper demoHelper = new DemoHelper();
		System.out.println("---curren year:"+demoHelper.getCurYear());
		DemoVO demoVO = new DemoVO();
		demoVO.setCode(1);
		List<DemoVO> listDemoVO = demoDao.selectByCode(demoVO);
		for(int i=0;i <listDemoVO.size(); i++){
			System.out.println("---i:"+listDemoVO.get(i).toString());
		}
		this.testLog4j();
		return "success";
	}

	public void testLog4j(){
		logger.info("info");
		logger.warn("warn");
		logger.debug("debug");
		logger.error("error");
		logger.fatal("fatal");
	}
}

（7）重启域服务，控制台输出应用的磁盘路径。如下图：