Application of the use of the web log tool log4J
Abstract: In the web application tools used in the log log4J
</ Td> </ tr> <tr> <td height="35" valign="top" class="ArticleTeitle"> Log4J Jakarta is under an open source code component, with Log4J, we can use custom the format of the debug information and log information to the output of one or more areas in need. Web applications in general use of a specialized Log4J Servlet to complete the configuration, and to ensure that the web.xml configuration, the other in the Servlet Servlet before, in order to call in the Servlet and jsp. Below is the servlet, the code below: Log4j WEB-INF/log4j.properties
<table Width="685" height="35" border="0"> <tr> <td width="399"> package example;
Import org.apache.log4j .*;
Import javax.servlet.http.HttpServlet;
Import javax.servlet.http.HttpServletRequest;
Import javax.servlet.http.HttpServletResponse;
Public class Log4jInit extends HttpServlet (
Public void init () (
String prefix = getServletContext (). GetRealPath ("/");
String file = getInitParameter ( "log4j ");// configuration file location
If (file! = Null) (
PropertyConfigurator.configure (prefix + file);
)
)
Public void doGet (HttpServletRequest req, HttpServletResponse res)
()
) </ Td> <td width="275"> </ td> </ tr> </ table>
In this servlet configure web.xml:
………..
Servlet>
………..
Log4J used to configure the properties of documents:
Log4j.rootLogger = debug, A1, R
Log4j.appender.A1 = org.apache.log4j.ConsoleAppender
Log4j.appender.A1.layout = org.apache.log4j.PatternLayout
Log4j.appender.A1.layout.ConversionPattern =% d (-yyyy-MM-dd HH: mm: ss) [% c] - [% p]% m% n
Log4j.appender.R = org.apache.log4j.RollingFileAppender
Log4j.appender.R.File = cwblog4j.log
Log4j.appender.R.MaxFileSize = 100KB
Log4j.appender.R.MaxBackupIndex = 1
Log4j.appender.R.layout = org.apache.log4j.PatternLayout
Log4j.appender.R.layout.ConversionPattern t =% p% c% -% m% n
This configuration file specified two output sources A1 and R. The former log information output to the console, which is a Web log files. The largest file is 100 KB, when a log file reaches the maximum size, Log4J automatically example.log example.log.1 to rename, and then the rebuilding of a new example.log documents were rotate.
Test documents:
<% @ Page contentType = "text / html; charset = GB2312"%>
<% @ Page import = "org.apache.log4j .*"%>
<%
Logger logger = Logger.getLogger ( "test.jsp");
Logger.debug ( "befor say hi");
%>
Hi
<% Logger.info ( "after say hi ");%>
On the server, $ TOMCAT_HOME/log4j.log document that the following information:
DEBUG Thread-5 testlog4j.jsp - befor say hi
INFO Thread-5 testlog4j.jsp - after say hi
In the $ TOMCAT_HOME / logs / stdout.log the final document has the following output.
Information: Server startup in 5678 ms
2004-07-07 09:54:05 [testlog4j.jsp] - [DEBUG] befor say hi
2004-07-07 09:54:05 [testlog4j.jsp] - [INFO] after say hi </ td> </ tr> <tr>
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Tags: log4j