Java Web log Details

First step: First set up a Web project, go to log4j website under the log4j jar package into the project Lib directory

The second step: in the SRC directory to build a log4j.properties file, file naming can be by themselves, just remember loading time and the name of the same line;

The contents of log4j.properties are as follows:

# # # set log levels # # #
Log4j.rootlogger = Debug,stdout,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 =%d{absolute}%5p%c{1}:%l-%m%n

Log4j.appender.e= Org.apache.log4j.DailyRollingFileAppender
Log4j.appender.e.file =${catalina.home}/logs/log_
Log4j.appender.e.datepattern=yyyy-mm-dd '. Log '
Log4j.appender.e.threshold =debug
Log4j.appender.e.layout = Org.apache.log4j.PatternLayout
Log4j.appender.e.layout.conversionpattern =%-d{yyyy-mm-dd hh\:mm\:ss}[%c] [%t\:%r]-[%p]%m%n

You can specify a single log output to a file:

Log4j.logger.pay-log=info,pay-loglog4j.appender.pay-log=org.apache.log4j.dailyrollingfileappender Log4j.appender.pay-log.file=d:/logs/pay-log.loglog4j.appender.pay-log.datepattern= '. '  Yyyy-mm-ddlog4j.appender.pay-log.threshold =debuglog4j.appender.pay-log.layout=org.apache.log4j.patternlayout Log4j.appender.pay-log.layout.conversionpattern =%-d{yyyy-mm-dd hh\:mm\:ss}[%c] [%t\:%r]-[%p]%m%n

Explain the next few common, the other in detail, please go to the Internet to find information:
Log4j.rootlogger = debug,stdout,e   means that the parent class logger will be output to a log higher than the debug level Stdout,e two places, subclasses are the same. The
stdout is a logging configuration that means that the log is output to the console, which is the configuration property--->log4j.appender.stdout.target = System.out &NBSP, when the time comes to production can be annotated off on it.
E is a logging configuration that logs log files to a file, Log4j.appender.e.file =${catalina.home}/logs/log_  is the path where the log files are placed, where ${ Catalina.home} is the path to the container
log4j.appender.e= org.apache.log4j.dailyrollingfileappender  This property configuration is a day to produce a new log file (there are other configuration methods, this is the most used)
Log4j.appender.e.datepattern=yyyy-mm-dd '. Log '    This property is a time-based file log with the following form:
Log_2011-06-26.log,log_2011-06-28.log, but the first log file generated is the name: Log_
Log4j.appender.e.layout.conversionpattern =%-d{yyyy-mm-dd hh\:mm\:ss}[%c] [%t\:%r]-[%p] %m%n  This is the output log content format, please check the information yourself;
Log4j.appender.e.threshold =debug  This is the output log level (meaning that only log information that is higher than the DEBUG level is output);

#appender名字定义
Log4j.rootlogger=info,file,consoleappender,rollingfile,mail,dailyrollingfile,database
Log4j.addivity.org.apache=true

#配置日志信息输出目的地
#log4j. Appender.appendername = Fully.qualified.name.of.appender.class
# (eg: log4j.appender.RollingFile = org.apache.log4j.RollingFileAppender)
# 1.org.apache.log4j.consoleappender (console)
# 2.org.apache.log4j.fileappender (file)
# 3.org.apache.log4j.dailyrollingfileappender (Generate one log file per day)
# 4.org.apache.log4j.rollingfileappender (creates a new file when the file size reaches the specified size)
# 5.org.apache.log4j.writerappender (send log information in stream format to any specified location)

#配置日志信息的格式
#log4j. appender.appenderName.layout = Fully.qualified.name.of.layout.class
# (eg: log4j.appender.RollingFile.layout = org.apache.log4j.HTMLLayout)
# 1.org.apache.log4j.htmllayout (Layout in HTML table Form),
# 2.org.apache.log4j.patternlayout (with flexibility to specify layout mode),
# 3.org.apache.log4j.simplelayout (contains the level of log information and the information string),
# 4.org.apache.log4j.ttcclayout (contains information about the time, thread, category, etc.) of log generation

#日记记录的优先级: Priority, from high to low
# OFF, FATAL, ERROR, WARN, INFO, DEBUG, all.
# LOG4J recommends using only the five levels of fatal, ERROR, WARN, INFO, Debug.
# error is a serious error, mainly a program bug
# WARN for general warnings, such as session loss
# Info is the general information to display, such as login log out
# Debug information for the program debug

#输出格式: The parameters in layout begin with%, and subsequent parameters represent different formatting information (the parameters are listed in alphabetical order):
#%c outputs the full name of the class, which can be modified to%d{num}, the dimension that the Num class name outputs (such as: "Org.apache.elathen.ClassName",%c{2} will output elathen. ClassName)
#%d output log time in the format%d{yyyy-mm-dd hh:mm:ss,sss}, you can specify a format such as%d{hh:mm:ss}
#%l Output Log event location, including class name, thread occurrence, number of lines in code
#%n Line break
#%m Output code specifies information, such as info ("message"), output message
#%p output priority, i.e. FATAL, ERROR, etc.
#%r the number of milliseconds to output from boot to display the log information
#%t Output The name of the thread that generated the log event

#ConsoleAppender, console output
#FileAppender, file log output
#SMTPAppender, outgoing mail output log
#SocketAppender, Socket log
#NTEventLogAppender, Window NT log
#SyslogAppender,
#JMSAppender,
#AsyncAppender,
#NullAppender

Step Three: Configure the container to load the log4j configuration file when it is started:
Create a servlet content as follows:

Package com.tchzt.logTest;

Import javax.servlet.ServletException;
Import Javax.servlet.http.HttpServlet;

Import Org.apache.log4j.PropertyConfigurator;

public class Log4jinit extends HttpServlet {
Private static final long serialversionuid = 1L;
public void Destroy () {
Super.destroy ();
}

Public Log4jinit () {
Super ();
}

/**
* Initialization of the servlet. <br>
*
* @throws Servletexception If an error occurs
*/
public void Init () throws Servletexception {
String file =this.getinitparameter ("log4j");//read from Web. XML configuration, name must be consistent with Web. XML configuration
if (file! = null) {
Propertyconfigurator.configure (file);
}
}

}

Web. XML configuration:
<servlet>
<servlet-name>Log4jInit</servlet-name>
<servlet-class>com.tchzt.logTest.Log4jInit</servlet-class>
<init-param>
<param-name>log4j</param-name>//the name is the identity of the bottom path configuration (like key)
<param-value>/web-inf/classes/log4j.properties</param-value>//This is the path to load the log4j configuration file when the container initializes (this is like a value);
</init-param>
</servlet>

Okay, basically, the configuration is done, and the test begins:
Test class: Create a servlet content as follows:

Package com.tchzt.logTest;

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.log4j.Logger;

public class Test extends HttpServlet {

Private static final long serialversionuid = 1L;

/**
* The Doget method of the servlet. <br>
*
* This method was called when a form had its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response The response send by the server to the client
* @throws servletexception If an error occurred
* @throws IOException If an error occurred
*/
public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {
If the direct Classname.class log is output to the global Rootlogger specified file
Logger Logger = Logger.getlogger (Test.class.getName ());
If the logger name is specified, the log is output to the log file specified by the Pay-log.
Logger Logger = Logger.getlogger ("Pay-log");
Mylog4j.getsomething ();
System.out.println ("================97987==============");
Logger.info ("Log information start!");
Logger.info ("Log information end!");
try {
Integer.parseint ("a");
} catch (NumberFormatException e) {
Logger.error ("Parsing of numbers appears to be abnormal", e);
E.printstacktrace ();
}
}

/**
* The DoPost method of the servlet. <br>
*
* This method was called when a form had its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response The response send by the server to the client
* @throws servletexception If an error occurred
* @throws IOException If an error occurred
*/
public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {
This.doget (request, response);
}

}

The Web. XML configuration for this servlet is as follows:
<servlet>
<servlet-name>Test</servlet-name>
<servlet-class>com.tchzt.logTest.Test</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>Test</servlet-name>
<url-pattern>/servlet/Test</url-pattern>
</servlet-mapping>

Boot container: Output url:http://localhost:8080/log4jwebtest/servlet/test
The second time to close the container, modify the system time; In the boot container, the last generated log file is as follows:

Log_;log_2011-06-26.log;log_2011-06-28.log;log_2011-06-30.log

Content Select a file here:
2011-06-30 21:59:28[test.jsp] [http-8080-2:0]-[ERROR] Asdfasdf
2011-06-30 21:59:28[test.jsp] [http-8080-2:16]-[INFO] test Logging in JSP
2011-06-30 21:59:28[test.jsp] [http-8080-2:16]-[FATAL] test FATAL logging in JSP page.
2011-06-30 21:59:28[test.jsp] [http-8080-2:16]-[ERROR] parsing number exception
Java.lang.NumberFormatException:For input string: "A"
At java.lang.NumberFormatException.forInputString (Unknown Source)
At Java.lang.Integer.parseInt (Unknown Source)
At Java.lang.Integer.parseInt (Unknown Source)
At Org.apache.jsp.index_jsp._jspservice (index_jsp.java:90)
At Org.apache.jasper.runtime.HttpJspBase.service (httpjspbase.java:70)
At Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
At Org.apache.jasper.servlet.JspServletWrapper.service (jspservletwrapper.java:393)
At Org.apache.jasper.servlet.JspServlet.serviceJspFile (jspservlet.java:320)
At Org.apache.jasper.servlet.JspServlet.service (jspservlet.java:266)
At Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
At Org.apache.catalina.core.ApplicationFilterChain.internalDoFilter (applicationfilterchain.java:290)
At Org.apache.catalina.core.ApplicationFilterChain.doFilter (applicationfilterchain.java:206)
At Org.apache.catalina.core.StandardWrapperValve.invoke (standardwrappervalve.java:233)
At Org.apache.catalina.core.StandardContextValve.invoke (standardcontextvalve.java:175)
At Org.apache.catalina.core.StandardHostValve.invoke (standardhostvalve.java:128)
At Org.apache.catalina.valves.ErrorReportValve.invoke (errorreportvalve.java:102)
At Org.apache.catalina.core.StandardEngineValve.invoke (standardenginevalve.java:109)
At Org.apache.catalina.connector.CoyoteAdapter.service (coyoteadapter.java:263)
At Org.apache.coyote.http11.Http11Processor.process (http11processor.java:844)
At Org.apache.coyote.http11.http11protocol$http11connectionhandler.process (http11protocol.java:584)
At Org.apache.tomcat.util.net.jioendpoint$worker.run (jioendpoint.java:447)
At Java.lang.Thread.run (Unknown Source)
2011-06-30 21:59:37[com.tchzt.logtest.mylog4j] [http-8080-2:8641]-[ERROR] Java.io.filenotfoundexception:f:\tt.txt (The system cannot find the file specified.) )
2011-06-30 21:59:37[com.tchzt.logtest.test] [http-8080-2:8656]-[INFO] log information start!
2011-06-30 21:59:37[com.tchzt.logtest.test] [http-8080-2:8656]-[INFO] The end of the log message!
2011-06-30 21:59:37[com.tchzt.logtest.test] [http-8080-2:8656]-[ERROR] parsing number exception
Java.lang.NumberFormatException:For input string: "A"
At java.lang.NumberFormatException.forInputString (Unknown Source)
At Java.lang.Integer.parseInt (Unknown Source)
At Java.lang.Integer.parseInt (Unknown Source)
At Com.tchzt.logTest.Test.doGet (test.java:33)
At Javax.servlet.http.HttpServlet.service (httpservlet.java:690)
At Javax.servlet.http.HttpServlet.service (httpservlet.java:803)
At Org.apache.catalina.core.ApplicationFilterChain.internalDoFilter (applicationfilterchain.java:290)
At Org.apache.catalina.core.ApplicationFilterChain.doFilter (applicationfilterchain.java:206)
At Org.apache.catalina.core.StandardWrapperValve.invoke (standardwrappervalve.java:233)
At Org.apache.catalina.core.StandardContextValve.invoke (standardcontextvalve.java:175)
At Org.apache.catalina.core.StandardHostValve.invoke (standardhostvalve.java:128)
At Org.apache.catalina.valves.ErrorReportValve.invoke (errorreportvalve.java:102)
At Org.apache.catalina.core.StandardEngineValve.invoke (standardenginevalve.java:109)
At Org.apache.catalina.connector.CoyoteAdapter.service (coyoteadapter.java:263)
At Org.apache.coyote.http11.Http11Processor.process (http11processor.java:844)
At Org.apache.coyote.http11.http11protocol$http11connectionhandler.process (http11protocol.java:584)
At Org.apache.tomcat.util.net.jioendpoint$worker.run (jioendpoint.java:447)
At Java.lang.Thread.run (Unknown Source)

Java Web log Details