Log4j Properties File Configuration - log4j

I'm using Log4j for logging my system events.
Initially I used the Log4j properties file and then shifted to log4j.xml file.
My application has another property file - system.properties - that takes the configuration parameters.
I want the log output file to be specified in the application properties file - system.properties and refer the properties file in the log4j.xml file and also update the configuration.
Is it possible with this log4j.xml configuration?

You can do it by using ant scripts. Load the system.properties file in ant and replace the value inside the log4j.xml file.
Refer to this link on how to update XML file.
How to update an XML document with Ant

Related

Log files not rolling when we use both log4j2 and log4j configurations

We have configured both log4j.xml and log4j2.xml for our application due to certain limitations.
The legacy rolling file appender is configured in log4j.xml and the same file appender is used in log4j2.xml. The logs are written to the same file until the threshold for rolling reached. When a new backup file created, the logs defined in log4j2.xml are still writing to the backup file instead of the main file. Is there any way to solve this problem?

How to read level changes from log4j.xml when application is running

I am running a executable jar file, which logs using log4j.xml(version 1.2).
Whenever i change the log level in the xml file, i have to restart the java application for the new log level to reflect.
Can i add some configuration in the log4j.xml so that new log level will be taken into account without application restart?
Thanks,
-Venkat
Log4j 1.x has reached end of life on August 5, 2015. So I would like to recommend you to use log4j 2.x which supports this with the monitorInterval configuration.
However according to the log4j 1.x docs here it does support log level changes runtime.
How can I change log behavior at runtime?
Log behavior can be set using configuration files which are parsed at
runtime. Using configuration files the programmer can define loggers
and set their levels.
The PropertyConfigurator defines a particular format of a
configuration file. See also the examples/Sort.java example and
associated configuration files.
Configuration files can be specified in XML. See log4j.dtd and
org.log4j.xml.DOMConfigurator for more details.
See the various Layout and Appender components for specific
configuration options.
In addition to configuration files, the user may disable all messages
belonging to a set of levels. See next item.

How do I override default nlog configuration?

We ship a framework assembly for logging which internally uses nlog. We also ship an embedded nlog configuration as a resource in our assembly and read this on startup (a static constructor within our wrapper which wraps over the nlog wrapper using the XmlLoggingConfiguration class).
We would now like developers to be able to specify/override additional configuration via an external file for their own loggers (using the same nlog configuration file format).
Can we:
Refer include files in our embedded nlog configuration file? How is the path of the include file resolved? If we do this, does the content of the include file override the content of the embedded nlog configuration we read on startup?
Can developers use the nlog configuration section? Does the content of this section override the default configuration we have specified pro grammatically?
Any other options?
How is the path of the include file resolved?
You can use in the included file name:
layout renderers such as ${baseDir},
nlog variables.
If the resulting filename is not absolute, it is combined with the directory, where the original NLog configuration was located, but this may be null in your case, so you are limited to first 2 options.
does the content of the include file override the content of the embedded nlog configuration?
No, this content is added to the content of the embedded configuration.
Does the content of nlog configuration section override the default configuration we have specified programmatically?
When you set the configuration programatically, you override any configuration that was set before and also disable the automatic configuration discovery, including one from application configuration file or NLog.config.
But you can check whether the configuration is not null first time before you set the embedded value. This will trigger the automatic discovery, and in case if any logging configuration is found, the returned value would be non-null.

where to put log4j.properties- for use in java desktop app

I am trying to use log4j logging framework in a java desktop application.
When I run the code I am getting a message
log4j: log4j:WARN No appenders could be found for logger
I googled for the above error and found that it occurs when the log4j.properties file is not found by the app.
I am creating the desktop app using Eclipse. Currently log4j.properties is within the same folder that contains the source (in 'src' folder). Where should I put this file to make it work properly?
log4j will use a Default Initialization Procedure to find your configuration file. The documentation notes:
The preferred way to specify the default initialization file is through the log4j.configuration system property
If this property is not set - log4j will look at the classpath. In your case you have to place the file in the src directory (assumed that the content will be put in the classes path while you build the system). If you use maven place the file to the src/main/resources directory.
As you placed your file to the src directory check, that the file get transferred to the top level directory of your compiled classes.
Keep the properties file in the classes folder i.e. the folder that contains the classes (specially the main class).
Another reason for getting this error may be the wrong appenders or an appender without setting.

Logging via FileAppender

here is an easy question coming:
i am trying to use log4net to log the infos on a file. i wrote
< file value="log-file.txt" /> into my appender tag in app.config. and now wondering where the log-file.txt is positioned and whether it is created automatically or i should create it by myself.
i am using c# - wpf
It should be in the Debug\Bin or Release\Bin folder.
if its not there, try specifying full path.
The file will automatically be created if it doesn't exist.
It may require that the application has write permission to the folder where the logfile is placed.
As Orentet mentions this is normally the bin folder.

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