Log File Is Created But File Is Empty

log4net log file is created but always empty

There is probably a problem in your configuration, enable internal debug to see what it is:

<configuration>
...
    <appSettings>
        <add key="log4net.Internal.Debug" value="true"/>
    </appSettings>

...

    <system.diagnostics>
        <trace autoflush="true">
            <listeners>
                <add 
                    name="textWriterTraceListener" 
                    type="System.Diagnostics.TextWriterTraceListener" 
                    initializeData="C:\tmp\log4net.txt" />
            </listeners>
        </trace>
    </system.diagnostics>
</configuration>

Log4net FAQ

Python logging creates empty log file

I found the problem ! I didn't realize but when defining handlers in the log.conf file, the order of the handlers and formatters is important !

I changed the log.conf changed to:

[loggers]
keys=root,sLogger

[handlers]
keys=consoleHandler,fileHandler

[formatters]
keys=consoleFormatter, fileFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler, fileHandler

[logger_sLogger]
level=DEBUG
handlers=consoleHandler, fileHandler
qualname=sLogger
propagate=0

[handler_consoleHandler]
class=StreamHandler
level=WARNING
formatter=consoleFormatter
args=(sys.stdout,)

[handler_fileHandler]
class=FileHandler
level=WARNING
formatter=fileFormatter
args=('%(logfilename)s','a')

[formatter_fileFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s


[formatter_consoleFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s

NOTE the changed order between consoleFormatter and fileHandler in the [formatters] section.

The rest is working perfectly fine.

To make it easier to play around with I put it in a function (which is probably redundant I suppose):

def base_logger(path_conf, fname, savedir):
    '''
    Base logging function to be started once
    in the main script then used in every other
    modules.

    Args:
        - path_conf: str, path to the configuration
        file {log.conf}
        - fname: str, name of the saved log file
        - savedir: str, path of the saving directory

    Returns:
        - logging object to be used in the other scripts

    Example:
        In main.py:
            main():
                base_logger(paht_cong = './log.conf', fname='file', savedir='project)
        
        In module.py:
            # AFTER all the import
            logger = logging.getLogger(__name__) # To ge the module name reported in the log file
            ...
            logger.error(f'Error message regarding variable {var}')

        The logger initialization {logger = logging.getLogger(__name__)},
         has to be done in every file that will use logging !

    '''
    logging.config.fileConfig(fname=path_conf,
                                defaults={'logfilename': os.path.join(savedir, f'{fname}.log')}, 
                                disable_existing_loggers=False)

I would add that the logger = logging.getLogger(__name__) has to be placed after all imports to make sure that the module name displayed in the log is not imported from other modules.

Logback log file empty

Probably you missed the logback-core dependency.

<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-core</artifactId>
    <version>1.2.10</version>
</dependency>

or

dependencies {
    ...
    implementation 'ch.qos.logback:logback-core:1.2.10'
    ...
}

In addition to the other two you already have.

Other thing to do is to update to the latest versions of each dependency and see if the problem still occurs.

Reference: https://sematext.com/blog/logback-tutorial/ or https://www.baeldung.com/logback

log4j2 creates empty logs file

I case someone has this same problem, I've just solved it.
The problem was the way I was loading the xml config; I've changed it like this:

LoggerContext ctx = getLoggerContext();
ConfigurationSource configurationSource = new ConfigurationSource(new FileInputStream(new File(log4Jcfg)));
ctx.start(ConfigurationFactory.getInstance().getConfiguration(ctx, configurationSource));

and now it works perfect!

Log file gets created but remains empty?

You don't need the CheckFile() method. AppendText() will create the file if necessary.

The real problem is how you're writing the file. Change your method to this:

public static string Log(string code, string message)
{
    string log;
    using (var writer = File.AppendText(FilePath))
    {
        log = ("\r\n" + code + ": \n");
        log += String.Format("{0} {1}\n", DateTime.Now.ToLongTimeString(),
            DateTime.Now.ToLongDateString());
        log += String.Format("  :{0}\n", message);
        log += String.Format("-------------------------------");
        writer.WriteLine(log);
    }

    return log;
}

To clarify, the using block calls Dispose() on the StreamWriter. This flushes content to the file.

Generating empty log files with Log4J2

So, I have managed to output the logs to the file and to the console:

appender.file.type = File
appender.file.name = file
appender.file.fileName=target/myLog.log
appender.file.layout.type=PatternLayout
appender.file.layout.pattern=%d [%-15.15t] %-5p %-30.30c{1} - %m%n

appender.out.type = Console
appender.out.name = out
appender.out.layout.type = PatternLayout
appender.out.layout.pattern = %d [%-15.15t] %-5p %-30.30c{1} - %m%n
rootLogger.level = all
rootLogger.appenderRef.file.ref = file
rootLogger.appenderRef.file.ref = out

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