做了一个最简单的servlet项目,只有一个servlet,然后想在servlet把日志记录到项目下的logs文件夹中的logRecord.log和logRecorderror.log。
然而路径问题弄了我一天,找了很多资料,绝对路径是可以解决,但是如果移植的话,那么绝对路径改起来会很麻烦。所以最好用相对路径。
但是网上的相关资料都无法解决我的问题,后来一不做二不休,瞎弄,发现路径直接写logs/logRecord.log竟然成功的把日志写入进去了。
好了,话不多说 直接上代码。
1.首先我们把
commons-logging-1.1.3.jar
log4j-1.2.17.jar
导入到项目中。
2.配置log4j.properties
### set log levels ### log4j.rootLogger = INFO, stdout, D, E #log4j.rootLogger = INFO, stdout #log.path = /mylog ###ãè¾åºå°æ§å¶å° ### 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{yyyy/MM/dd-HH:mm:ss} [%-5p] [%c] [%F] - %m %n ### è¾åºå°æ¥å¿æ件 ### log4j.appender.D = org.apache.log4j.DailyRollingFileAppender log4j.appender.D.File = logs/logRecord.log log4j.appender.D.DatePattern='.'yyyy-MM-dd log4j.appender.D.Threshold = INFO log4j.appender.D.layout = org.apache.log4j.PatternLayout log4j.appender.D.layout.ConversionPattern = %d{yyyy/MM/dd-HH:mm:ss} [%-5p] [%c] [%F] - %m %n log4j.appender.D.layout.Encoding=UTF-8 ### ä¿åå¼å¸¸ä¿¡æ¯å°åç¬æ件 ### log4j.appender.E = org.apache.log4j.DailyRollingFileAppender ##å¼å¸¸æ¥å¿æ件 log4j.appender.E.File = logs/logRecorderror.log log4j.appender.E.Append = true ##åªè¾åºERROR级å«ä»¥ä¸çæ¥å¿ 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} [%-5p] [%c] [%F] - %m %n log4j.appender.E.DatePattern='.'yyyy-MM-dd log4j.appender.E.Encoding=UTF-8
这个是servlet,里面的main方法是来把日志写入文件中。
package com.pingpay.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class PingPayLogServlet extends HttpServlet { // 在任何需要记录日志的类中 Log log = LogFactory.getLog(this.getClass()); /** * 记录ping++返回的数据 * */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // response.setContentType("text/html"); // request.setCharacterEncoding("utf-8"); // response.setCharacterEncoding("utf-8"); log.info("into one method"); try { System.out.println(9 / 0); } catch (RuntimeException e) { log.error(e.getMessage()); } log.info("out one method"); } public static void main(String[] args) throws Exception { new PingPayLogServlet().doPost(null, null); System.out.println("1"); } }
项目结构如图。
因为我们在log4j.properties中设置了log4j.appender.D.Threshold = INFO,log4j.appender.E.Threshold = ERROR 。
所以error的日志会保存在logRecorderror.log文件中,
但是由于:DEBUG < INFO < WARN < ERROR < FATAL级别
log4j.appender.D.Threshold = INFO这句话
它的作用是输出INFO级别以上的内容到logRecord.log中,所以logRecord.log文件中包含了ERROR级别的文件。
如有错误,请指出,谢谢。
周一回来发现上面的方法不行了。我也是醉了,然后换了一种方法。
将日志文件输出到自己程序WEB-INF\logs目录中
1、在web.xml配置一个servlet
<servlet> <servlet-name>lo4jInit</servlet-name> <servlet-class>com.linder.util.log4j.init.Lo4jInit</servlet-class> <init-param> <param-name>log4j_init_path</param-name> <param-value>WEB-INF\classes\log4j.properties</param-value> </init-param> <init-param> <param-name>log4j_file_path</param-name> <param-value>WEB-INF\logs\</param-value> </init-param> <load-on-startup>0</load-on-startup> </servlet>
2、编写一个初始化log4j的Servlet
package com.linder.util.log4j.init; import java.io.FileInputStream; import java.io.IOException; import java.util.Properties; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; import org.apache.log4j.PropertyConfigurator; public class Lo4jInit extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; private static Logger logger=Logger.getLogger(Lo4jInit.class); public void init(){ String path=this.getServletContext().getRealPath("/"); String file=this.getInitParameter("log4j_init_path"); String logFile=this.getInitParameter("log4j_file_path"); if(file!=null) { Properties prop = new Properties(); try{ prop.load(new FileInputStream(path+file)); //加载log4j.properties prop.setProperty("log4j.appender.R.File", path+logFile+ prop.getProperty("log4j.appender.R.File")); //设置日志文件的输出路径 PropertyConfigurator.configure(prop); //加载配置项 }catch(Exception e) { logger.info("初始化log4j日志输入路径异常,请检查web.xml参数配置是否正常,异常发生在"+this.getClass().getName()+"类的public void init()方法,异常的愿意是:"+e.getMessage(), e.fillInStackTrace()); } } } protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } }
3、log4j.properties的配置信息
# Set root category priority to info and its only appender to console. log4j.rootCategory=info,console,R #log4j.debug=true # console is set to be a ConsoleAppender using a PatternLayout. 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=- %m%n # R is set to be a File appender using a PatternLayout. log4j.appender.R=org.apache.log4j.RollingFileAppender log4j.appender.R.Append=true log4j.appender.R.Threshold=info log4j.appender.R.MaxFileSize=1024KB log4j.appender.R.MaxBackupIndex=10 log4j.appender.R.File=abc.log log4j.appender.R.layout=org.apache.log4j.PatternLayout log4j.appender.R.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss} [%c]-[%p] %m%n
abc.log位于你项目的WEB-INF/logs的文件夹下。
我项目的XML配置为:
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" 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_3_0.xsd"> <servlet> <servlet-name>lo4jInit</servlet-name> <servlet-class>com.pingpay.servlet.Lo4jInit</servlet-class> <init-param> <param-name>log4j_init_path</param-name> <param-value>WEB-INF\classes\log4j.properties</param-value> </init-param> <init-param> <param-name>log4j_file_path</param-name> <param-value>WEB-INF\logs\</param-value> </init-param> <load-on-startup>0</load-on-startup> </servlet> <servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>PingPayServlet</servlet-name> <servlet-class>com.pingpay.servlet.PingPayServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>PingPayServlet</servlet-name> <url-pattern>/PingPayServlet</url-pattern> </servlet-mapping> </web-app>