Im creating a log file system. the log file will be in json format so a server can read it after but i dont think thats too important. What i need to know is can log4j be configured to write into to a file but without any tags like info,debug, timestamp etc in the file. I have looked here
but this polutes the file with with other things. I want ONLY the data i write to show up in the file. I'd also like to set some kind of file rotation on the file if it gets too big after a max size is reached.
This is relatively easy, using a log4j.properties configuration file (place it at the top of your classpath, and Log4j will 'just find it'):
# This is the default logger, simply logs to console
log4j.logger.com.foo.bar=DEBUG,A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
# Note the Pattern here, emits a lot of stuff - btw, don't use this in production
# %C is expensive - see the Javadoc for ConversionPattern for the meaning of all
# the % modifiers:
log4j.appender.A1.layout.ConversionPattern=%d{MMM dd, HH:mm:ss} [%C{2}] %-5p - %m%n
# Logging to file can be enabled by using this one
log4j.logger.com.example=DEBUG, R
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=/var/log/generic.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
# This is the most minimalist layout you can have: just the 'm'essage is emitted
# (and a \n newline):
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%m%n
All the classes in the com.foo.bar package (and subpackages) will log to console, those in com.example (and below) will log to /var/log/generic.log.
To emit JSON, just use Jackson (com.fasterxml) convert your data to a JSON object and write it out as a string.
What you want is the PatternLayout with %m%n only, and combine with the answer to previously asked question here
You should be able to write a custom log appender, I have a vague recollection of there being an example to do this with MongoDB.
MongoDD stores its data as JSON, so it have converted the log to json format before inserting it.
I would start by searching for a MondgoDB appender, and looking at the file appender that is shipped, that should give you a starting point for an appender if one doesnt already exist.
http://log4mongo.org/display/PUB/Home
Related
This is the log4j properties file we are using, could you please explain why the limit for number of files is stuck at 13 instead of 50 as defined in "maxIndex" Property?
# Root logger option
log4j.rootLogger=INFO,file,stdout
log4j.logger.com.cisco.assurance=DEBUG, file
# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.Threshold=DEBUG
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd'T'HH:mm:ss.SZ} %-5p %m%n
# Redirect log messages to a log file
log4j.appender.file=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.file.rollingPolicy=org.apache.log4j.rolling.FixedWindowRollingPolicy
log4j.appender.file.triggeringPolicy=org.apache.log4j.rolling.SizeBasedTriggeringPolicy
log4j.appender.file.rollingPolicy.FileNamePattern=/var/log/smeu/AssuranceMS-%i.log.gz
log4j.appender.file.rollingPolicy.ActiveFileName=/var/log/smeu/AssuranceMS.log
log4j.appender.file.triggeringPolicy.MaxFileSize=204800000
log4j.appender.file.rollingPolicy.maxIndex=50
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d [%t] %-5p (%F:%L) - %m%n
log4j.appender.file.Threshold=DEBUG
From the API of org.apache.log4j.rolling.FixedWindowRollingPolicy, it is reduced by design to 12 backups plus the current one, so 13 maximum.
You can look at it : https://logging.apache.org/log4j/extras/apidocs/org/apache/log4j/rolling/FixedWindowRollingPolicy.html
This is happening because large window size is discouraged and the maxIndex is automatically reduced to 12. It is well documented here.
Given that this rollover algorithm requires as many file renaming operations as the window size, large window sizes are discouraged. The current implementation will automatically reduce the window size to 12 when larger values are specified by the user.
How to write a Hebrew string to a log4j file. Right now I see ?????? in the file.
I have searched everywhere online to convert Unicode to string:
String abc = myStr.replaceAll("\u200F", "");
abc = abc.replaceAll("\u200E", "");
byte[] utf8Bytes = abc.getBytes(Charset.forName("UTF-8"));
String value = new String(utf8Bytes);
log.debug("value : "+ value );
I just need to write out a Hebrew string to a Log4j file in a readable format. Here is my configuration:
log4j.rootLogger=debug, stdout, R log4j.logger.testlogging=DEBUG
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd} %5p [%t] (%F:%L) - %m%n log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=C:\\dri\\ums.log log4j.appender.R.MaxBackupIndex=5
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern= %d{dd MMM yyyy HH:mm:ss,SSS} %5p [%t] (%F:%L) - %m%n log4j.appender.FILE.encoding=UTF-8
Based from what I've gathered from the comments and my own experience this is most probably not an issue with Log4j itself. I've posted a comment indicating just that:
What exactly do you mean with Log4j file? Is it a regular text log file that the FileAppender points to? Because I've tried printing Hebrew text right now and all is working out fine. I believe this is not a Log4j issue and might be related to your text reader.
Other comments have confirmed their suspicion that it is your text reader that might be causing this issue. I was able to reproduce your issue by doing the following in Notepad++:
Open a new tab in notepad++.
Copy and paste sample text containing Hebrew letters.
Language -> Convert to ANSI
Text before the conversion:
See also: אלף־בית and אַלף־בית
Text after conversion:
See also: ???????? and ?????????
Based on the code you provided (assuming there is no shenanigans that we don't know for behind the scenes) we can definitively conclude you are either writing to a file that has it's encoding set to ANSI where all your special characters are being converted to question marks because they cannot be decoded or your characters are being read as UTF-8 but merely displayed as ANSI.
ANSI and UTF-8 are both encoding formats. ANSI is the common one byte format used to encode Latin alphabet; whereas, UTF-8 is a Unicode format of variable length (from 1 to 4 bytes) which can encode all possible characters.
I would recommend following these steps:
Navigate to Settings -> Preferences -> New Document -> Encoding and make sure that the UTF-8 (Apply to opened ANSI files) option is selected.
Close all your files currently opened in Notepad++ and delete the log file. Make sure you are actually closing the files instead of just closing Notepad++. This should clear the file entries from cache and allow you to open them again with a different encoding.
Run your Java application and let Log4j print to the file.
Open the file with Notepad++ and check that you are encoding in UTF-8 by clicking on Encoding tab. If the option is not set to UTF-8, change it.
If none of the above worked, please post further information in the comments.
Unfortunately I am not that well versed in encoding matters and had to look some stuff up in the process of writing this, so I can't help you as much as I would like to. However in addition to providing the steps above I can direct you to the following links which should provide you with further knowledge and (consequently) more insight into your problem:
Encodings And Character Display - Notepad++ Wiki
ANSI to UTF-8 in Notepad++ - SuperUser
I fiddled around with a rolling file appender with autocompress to .gz, which gave me a lot of files like this:
foo_bar_1.gz
foo_bar_2.gz
...
and so on.
Next I changed the filePattern to "%d{yyyy-MM-dd}_%d{HH-mm-ss}.log.gz" which included a timestamp into the filename. Unfortunately our system management division can't use the timestamp, as this timestamp does not reflect the LAST insertion into the log (or at least the timestamp when rolling and compressing occured).
Is there any way to make Log4j2 to change the filename of the logfile (and of course of the compressed file) to the timestamp of the last insertion?
I have a log4j properties file and i want to generate log file on daily basis and remove the file before today i mean it should contains only today's log file.
I have used following Properties file:
log4j.rootLogger=ALL,Appender2
log4j.appender.Appender2=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Appender2.File=log/AlertLogfile.log
log4j.appender.Appender2.append=true
log4j.appender.Appender2.layout=org.apache.log4j.PatternLayout
From the docs of DailyRollingFileAppender
The rolling schedule is specified by the DatePattern option. This pattern should follow the SimpleDateFormat conventions. In particular, you must escape literal text within a pair of single quotes. A formatted version of the date pattern is used as the suffix for the rolled file name.
log4j.rootLogger=ALL,Appender2
log4j.appender.Appender2=org.apache.log4j.DailyRollingFileAppender
log4j.appender.Appender2.File=log/AlertLogfile.log
log4j.appender.Appender2.append=true
log4j.appender.Appender2.layout=org.apache.log4j.PatternLayout
log4j.appender.Appender2.DatePattern='.'yyyy-MM-dd
I supply a formatted java string with significant whitespace
String.format("%1$12s %2$15s", "someString", "anotherOne");
to be logged using the following conversion pattern in log4j
<param name="ConversionPattern" value="%d{ISO8601} %-5p [%t] %c{1} %m%n" />
In the logs, I receive the variable with just a single preceding whitespace.
... PatternStuff ... someString anotherOne
slf4j version 1.7.3
log4j version 1.2.14
Is it possible to show the whitespace added by String.format? Some other conversion pattern variable other than %m?
My workplace has an internal web-based logviewer that quickly gives developers a way to access the contents of log files. We have the ability to print logs out in a generated webpage or to download the log. When I view them in the browser, the spaces are collapsed (because of standard HTML output). However, when I download the log files, they appear with the given formatting! Sorry for the confusion.