In java web application, how to read log4j.xml fro

问题:

I wanted to put my log4j.xml file in WEB-INF/conf directory where I have many other configuration files. And I wanted the web application to read log4.xml from there.

I was trying to use spring3.0 and annotations. So not sure how to access the servlet context to get the WEB-INF location.

tried this

InputStream ist = Thread.currentThread().getContextClassLoader().getResourceAsStream("/conf/log4j-my.xml");

but it searches under to tomcat/bin/

Tried this but did't help much DOMConfigurator.configure("WEB-INF/conf/log4j-my.xml");

Would appreciate any help/links/pointer.

回答1:

Not sure what you really wanna do....

if your log4j.xml is in the classpath, when you start your app-server, it should be loaded automatically.

Check the console when you start your server and you should see your log4j info.

You can also put debug=true:

<log4j:configuration debug="true" xmlns:log4j="http://jakarta.apache.org/log4j/">

in your xml. you will be able to see a lot of info about your config.

Now if you want to access the appenders you configured in the log4j.xml, all you have to do is:

Logger mylogger = Logger.getLogger("MyAppenderName");

Ok, i think you wanna load a custom log4j config file! In a web app context, you will need 2 things:

create a contextListnerServlet; modify your web.xml

ServletListner:

public class StartupListener implements ServletContextListener
{
@Override
public void contextDestroyed(ServletContextEvent arg0)
{
    // Cleanup code goes here
}

@Override
public void contextInitialized(ServletContextEvent sce)
{
    Logger logger = null;
    String log4jFile = sce.getServletContext().getInitParameter("log4jFileName");
    DOMConfigurator.configure(sce.getServletContext().getRealPath(log4jFile));
    logger = LogManager.getLogger(StartupListener.class.getName());
    logger.debug("Loaded: " + log4jFile);
}

web.xml:

<context-param>
<param-name>log4jFileName</param-name>
<param-value>
     WEB-INF/config/log4j-my.xml
</param-value>
</context-param>

<listener>
<listener-class>
    com.yourpackage.StartupListener
</listener-class>
</listener>

Hope it helps