RegexFilter with RollingFileAppender not working properly - regex

Question

I am trying to use Regexfilter in RollingFileAppender. For 1st matching instance it retreived the logger, but after that I different patttern but nothing is logged in the file. Here is what I am using:
Main Class:
public class MainApp {
public static void main(String[] args) {
final Logger logger = LogManager.getLogger(MainApp.class.getName());
ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
HelloWorld obj = (HelloWorld) context.getBean("helloWorld");
logger.trace("NPF:Trace:Entering Log4j2 Example.");
logger.debug("NTL:debug Entering Log4j2 Example.");
obj.getMessage();
Company comp = new Company();
comp.setCompName("ANC");
comp.setEstablish(1889);
CompanyBusiness compBus = (CompanyBusiness)context.getBean("compBus");
compBus.finaceBusiness(comp.getCompName(), comp.getEstablish());
logger.trace("NTL: Trace: Exiting Log4j2 Example.");
}
}
log4j2.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<Configuration>
<Appenders>
<Console name="STDOUT" target="SYSTEM_OUT">
<PatternLayout pattern="%d{yyyy-MM-dd [%t] HH:mm:ss} %-5p %c{1}:%L - %m%X%n" />
</Console>
<RollingFile name="RollingFile" fileName="C:\logTest\runtime\tla\els3.log" append="true" filePattern="C:\logTest\runtime\tla\els3-%d{yyyy-MM-dd}-%i.log" >
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %m%X%n" />
<RegexFilter regex=".*business*." onMatch="ACCEPT" onMismatch="DENY"/>
<Policies>
<SizeBasedTriggeringPolicy size="20 MB" />
</Policies>
</RollingFile>
</Appenders>
<Loggers>
<Logger name="com.anc" level="trace"/>
<Root level="trace">
<AppenderRef ref="STDOUT" />
<AppenderRef ref="RollingFile"/>
</Root>
</Loggers>
</Configuration>
When I ran for the first time, in my logfile I got logs having only "business" related line. Latter I changed the patter from .business (pattern has astreik before and after business word). to "business", logging did not happen in file nor on the console. Also my application terminated without any kind of logging.
Then I tried to revert back the pattern to '.business.' (pattern has astreik before and after business word), thereafter no logging happened on the log file, but on the console all the log trace is printed. When I comment out the Regexfilter after trying for long time, my logs was printed in the log file.
I am not sure if this is a bug of Regexfilter works only for one time. Also if we do not pass any patter matching characters, the application stops without any log printing either on console or file.

Answer 1

If you want to log all events containing the word "business", then you shall use the regex .*business.* instead of .*business*.. Here is an example:
<RegexFilter regex=".*business.*" onMatch="ACCEPT" onMismatch="DENY"/>
For information, .*business*. means: anything, followed by business, followed by s character 0 or more time, followed by any single character.
More explaining:
. means any single character
* means 0 or more times
so .* means any character, 0 or more times.