Log4J configuration problem

[Kjeld Sigtermans]

Hello,

I am trying to use Log4J logging in a web application, deployed on BEA.
I am writing this down from memory since I can not access my code right now. My apologies.

First, in a Java class (e.g. mypackage.MyClass), I put code like:

private static final Logger LOGGER = Logger.getLogger(MyClass.class);
...
LOGGER.info("Log this.");

Second, I have created a log4j.properties file and I have put it in the web project's WEB-INF/classes folder (later on, I tried putting it in other classpath locations as well).
The properties file basically just defines the root logger, and configures it to a console output appender, at INFO level. I copied the property file content directly from an example, so I assume nothing is wrong with it (later on I tried to create a specific logger for "mypackage" as well).

When starting up the server and application, and passing through the code of MyClass, the following appears in the console output:

log4j:WARN No appenders could be found for logger (mypackage.MyClass)
log4j:WARN Please initialize the log4j system properly.

What do I need to do to get it working? It is a web application, so I assume I do not need to call some initialization method in advance, like I noticed in stand-alone Java application examples.

Thanks!
Kjeld

[Paul Clapham]

And does this logging configuration work (i.e. produce log output) when you use it in a simpler environment? E.g. not in a Java EE container, but in a plain old Java application?

[Kjeld Sigtermans]

I have not tried that, thanks. I will in the morning and post the result here.

[Kjeld Sigtermans]

Well the log4j.properties file works fine in a standalone Java application.
This is the file:

# STDOUT appender
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.ConversionPattern=%d %p [%t] %C{1} - %m\n

# use the STDOUT appender. set the level to INFO.
log4j.logger.log4jtest=INFO, STDOUT

Note that my standalone Java app is in a package called log4jtest.

I put the log4j.properties file in the classpath and before doing any logging I initialize log4j using:

File propertyFile = new File("log4j.properties");
Properties logProperties = new Properties();
logProperties.load(new FileInputStream(propertyFile));
PropertyConfigurator.configure(logProperties);

I understand that PropertyConfigurator.configure(...) does the trick, but I doubt this is the way to initialize Log4J in a web application?

[Sean Clark]

Hey,
I think the problem may be that the web application does not have a console as such.
Have you tried using the file appender in the web application?

Sean

[Kjeld Sigtermans]

I tried, but nog log file.
Right now I am creating a SetupServlet , loaded on startup, containing the initialization code.
Can't image this is the way to go, though.

Thanks!

[Tanzy Akhtar]

Hi Kjeld, i am curious whether have you resolved this problem.
Please share with us if you find the solution so that it ll be helpful to others.


Thanks,
Tanzy.

[Kjeld Sigtermans]

Hello Tanzy,

No change since my last post. The development team agreed in creating a Servlet called InitServlet that is loaded on startup, initializing the code in its 'init(ServletConfig)' method. Here's the method:

	public void init(ServletConfig servletConfig) throws ServletException {

		super.init(servletConfig);

	    Properties logProperties = new Properties();
	    File propertyFile = new File(servletConfig.getInitParameter("log4jprops"));
	    
	    try {
	    	logProperties.load(new FileInputStream(propertyFile));
	    	PropertyConfigurator.configure(logProperties);
	    }
	    catch(IOException e) {

	    	System.out.println("Unable to load logging properties from file location: " + propertyFile.getAbsolutePath());
	    	System.err.println("Unable to load logging properties from file location: " + propertyFile.getAbsolutePath());
	    }
	}
    

And the web.xml snipplet:

    <servlet>
    	<servlet-name>InitServlet</servlet-name>
        <servlet-class>mypackage.InitServlet</servlet-class>
        <init-param>
        	<param-name>log4jprops</param-name>
			<param-value>/[the path to props file]/log4j.properties</param-value>
        </init-param>
    	<load-on-startup>1</load-on-startup>
    </servlet>
    

Grtz,
Kjeld

[Tanzy Akhtar]

Thanks Kjeld for sharing the solution.