Develop Reference

logback Maskpattern for Email

Currently i am using the logback framework and patterns in my logs , but I need to mask the PII information for email-id. I need The regular expression which helps to Mask my email Address from the logs, my requirement was to mask only 30% of the email id.
Since i am using the Logback we can use the logback and masking pattern
<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
<maskPattern>(?<=.{3}).(?=[^#]*?#)</maskPattern> <!--mask email-->
</encoder>
</appender>
For example : testing#test.com
Expected Result:tes***#test.com
I tried Using Different Regular expressions from google and none of them works with the logback framework. For example when i use the below regular expression in logback.xml was not able to parse it or compile it. i have taken reference as :
https://howtodoinjava.com/logback/masking-sensitive-data/
<maskPattern><![CDATA[/(?<=.{3}).(?=[^#]*?#)]]></maskPattern>
<maskPattern><(?<=.{3}).(?=[^#]*?#)></maskPattern>
Examples: Can any body please provide me the correct regular expression or pattern, below are the regular expression or pattern i tried none of them works.
1) (?<=.{3}).(?=.*#)
2) (?<=.{2}).(?=[^#]*?#)
3) ([^#]{4})[^#]*(.+)
4) \\b(\\w)[^#]+#\\S+(\\.[^\\s.]+)
please check the screen shot below.
enter image description here
ref: https://stackoverflow.com/questions/33100298/masking-of-email-address-in-java

Log4j2 SyslogAppender Set Layout Programmatically

i recently had the necessity to migrate from log4j 1.x to log4j 2.x.
In my code, i dynamically instantiate different Syslog appenders which may use two different layout types.
I'm using a getSysLogAppender method to generate a SyslogAppender object whenever i need in my code. Unfortunately, if i set the layout using the setLayout() function, my logs do not get sent one-at-a-time as i've expected. If i remove the setLayout() function from the builder and just leave the setFormat("RFC5424"), logs are sent correctly.
Due to application needs, i cannot just take the RFC5424 as it is implemented in log4j2, i need to customize the layout of the logs.
Looking at log4j2 SyslogAppender source code, if the format is RFC5424 and a layout is given, format RFC5424 is not taken into consideration: https://github.com/apache/logging-log4j2/blob/release-2.x/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/SyslogAppender.java (line 114).
What's the correct way to customize the SyslogAppender layout?
Thanks in advance.
// Class variables
private static final String pattern1 = "%d %-1p - %m";
private static final String pattern2 = "%d %-5p [%t] %-4c{2} (%13F:%L) %3x - %m";
private static final String hostname = "localhost";
private static final String port = "2601";
private void createAppender() {
Appender appender = getSyslogAppender("TESTID", Facility.USER, pattern1); //third parameter may be also pattern2 var
appender.start();
}
// Method that generates my appender
private SyslogAppender getSyslogAppender(String id, Facility facility, String pattern) {
return SyslogAppender.newSyslogAppenderBuilder().withProtocol(myprotocol).withHost(hostname).withPort(port).setFacility(facility).setId(id).withBufferedIo(false)
.setLayout(org.apache.logging.log4j.core.layout.PatternLayout.newBuilder().withPattern(pattern).build())
.setName("log4jAppender").withImmediateFlush(true).setNewLine(true).setFormat("RFC5424").build();
}

Log4j2 Different color per logger

In my project I use Log4j 2.17.1.
I would like to format the output so that the class names have different colors.
public class MyClass {
Logger LOGGER = LogManager.getLogger(MyClass.class.getSimpleName());
//...
LOGGER.debug("Some Information");
}
public class MySecondClass {
Logger LOGGER = LogManager.getLogger(MySecondClass.class.getSimpleName());
//...
LOGGER.debug("Another Output");
}
In my example, I want the two classes to appear in different (perhaps random) colors (instead of yellow as in the example).
My current pattern layout:
%highlight{${LOG_LEVEL_PATTERN:-%5p}}{FATAL=red blink, ERROR=red, WARN=yellow bold, INFO=green, DEBUG=green bold, TRACE=blue} : %style{%logger{36}:}{blue} %msg%n
Is this possible with Log4j?

Per defeault log4j writes simple text files with no fancy formatting applied (FileAppender, ConsoleAppender).
I have never done this, but I believe you can add ANSI escape sequences using a suitable formatting pattern, then enjoy the colours when the log output is sent to a terminal capable of understanding these sequences.

log4j2: custom formating for pattern parameter

Usually logging looks like this:
Duration duration = ...;
log.info("Duration: {}", duration);
But what do if you need custom formatting?
if (log.isInfoEnabled()) {
String value = duration.toSeconds() + "." + duration.toMillis();
log.info("Duration: {}", value);
}
In this case code is complicated. I'm looking for a way to do simple logging as in first sample but to be able to customize value formatting using some mechanism, e.g, define a format function for given type:
LogSystem.install(Duration.class, duration -> {
return String.format("%d.%d", duration.toSeconds(), duration.toMillis();
});
Questions:
does log4j 2.x have such or similar feature?
may be it exists in other logging libraries?
if no, can if (log.isInfoEnabled()) { ... } be simplified somehow?

does log4j 2.x have such or similar feature?
Yes, you can use
log.info("Duration: {}.{}", duration.toSeconds(), duration.toMillis());
You can pass as many parameters as you like. If you use parameterized logging, you don't need to check log.isInfoEnabled().
may be it exists in other logging libraries?
SLF4j also supports parameterized logging.

Yes, you can do it using the properties file.Set policies pattern in your log4j2.properties file like:
appender.rolling.type = RollingFile
appender.rolling.name = RollingFile
appender.rolling.fileName = ABClog/ABCapplication.log
appender.rolling.filePattern = ABClog/ABCapplication.%d{dd-MMM}.log
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = { [%-5level %d{dd-MM-yyyy hh:mm:ss.SSS } ] [%msg] }%n
After setting the above configuration in your log4j2.proerties file, you will get your desired output, even using properties file concept you can add extra info too e.g. Correlation-ID
log.info("hello")
Log4j2 document for more pattern style: https://logging.apache.org/log4j/2.x/manual/layouts.html

How to print event level in lowercase using log4j12?

Is there any possibility to print event levels to log in lower case in log4j 2?
Like %level{lowerCase=true} in pattern in Log4j 2.
Can I process result string somehow, or use custom renderer?

You have to set a pattern to the appropriate appender in the log4j.properties file.
For instance, with ConsoleAppender:
log4j.appender.ConsoleAppender.layout.ConversionPattern=%d [%p{lowerCase=true}] %c{1} - %m%n
You can check the output here.