My configuration simply has %msg in the pattern layout to output the message.  
However, that seems to be outputting the message along with some serialized 
representation of the exception.  I was looking at the message pattern 
converter at:


https://github.com/apache/logging-log4j2/blob/master/log4j-core/src/main/java/org/apache/logging/log4j/core/pattern/MessagePatternConverter.java


which I assume is what formats the string for the %msg pattern.  Is that 
correct?  I don't see in the code where it's getting the exception info, but I 
guess it might already be in the Message object.


Thanks,

Nick

________________________________
From: Ralph Goers <ralph.go...@dslextreme.com>
Sent: Sunday, November 6, 2016 1:38 AM
To: Log4J Users List
Subject: Re: looking for source

If you look at PatternLayout you will see a few choices for how the Exception 
gets formatted. %ex uses printStackTrace to format the Exception, however that 
is not the default. We extend the stack trace to also include the source of 
each class (i.e. the jar or class directory) and its version, if it can be 
determined. Other Layouts may, or may not, format the Exception depending on 
what they are attempting to do.

To take this further, there are many components that make up the log event - 
the level, Marker, message (with or without parameters), time, ThreadContext 
values, logger name, class name, method name, line number and the exception. 
Each of these are discrete values that the Layout can format (or not) as it 
chooses.

Ralph

> On Nov 5, 2016, at 6:33 PM, Nicholas Duane <nic...@msn.com> wrote:
>
> Thanks.  I have no problem doing that.  Just wondering what needs to be done 
> and how?  I guess I was hoping that the logging framework, eg. log4j, handled 
> combining the message and the exception such that no matter what 
> appender/layout you used you'd get consistent results.  Sounds like that's 
> not the case.  So are you saying I need to combine the message and the 
> exception myself within our appender/layout?
>
>
> From the code I included below you can see we're doing:
>
>
> String message = logEvent.getMessage().getFormattedMessage();
>
>
> to get the event's message.  Are you saying we should be doing something like 
> this:
>
>
> StringWriter sw = new StringWriter();
> logEvent.getThrown().printStackTrace(new PrintWriter(sw));
> String exceptionAsString = sw.toString();
> String message = logEvent.getMessage().getFormattedMessage() + "\n" + 
> exceptionAsString;
>
>
> Thanks,
>
> Nick
>
> ________________________________
> From: Remko Popma <remko.po...@gmail.com <mailto:remko.po...@gmail.com>>
> Sent: Saturday, November 5, 2016 9:16 PM
> To: Log4J Users List
> Subject: Re: looking for source
>
> The point is that in a custom layout/appender you should get the throwable 
> from the LogEvent, not from the Message. That is the design that all Layouts 
> and Appenders follow and should follow.
>
> The Message object passed to the Layout may no longer have the Throwable.
>
> Sent from my iPhone
>
>> On 6 Nov 2016, at 10:01, Nicholas Duane <nic...@msn.com> wrote:
>>
>> Thanks for the info.  Unfortunately I'm not following.  If someone can point 
>> me to the source in question I will certainly look it over.  My sample 
>> outputs the message (%msg) and when the method logger.error(String message, 
>> Throwable t) is called it seems some code is combining the supplied string 
>> message with the exception message and stack trace.  Just wondering what 
>> code is doing that as I'm told someone using our appender/layout is not 
>> seeing the exception.
>>
>>
>> Thanks,
>>
>> Nick
>>
>> ________________________________
>> From: Remko Popma <remko.po...@gmail.com>
>> Sent: Friday, November 4, 2016 9:58 PM
>> To: Log4J Users List
>> Subject: Re: looking for source
>>
>> The Throwable is initially captured in the Message (usually 
>> ParameterizedMessage or its garbage-free equivalent), but is later 
>> transferred to the LogEvent.
>>
>> By the time the LogEvent reaches the Layout, the Message instance may be a 
>> different Object than the one that originally held the Throwable.
>>
>> The Layout should get the Throwable from the LogEvent, not from the Message.
>>
>> Remko
>>
>> Sent from my iPhone
>>
>>> On 5 Nov 2016, at 7:50,Nicholas Duane <nic...@msn.com> wrote:
>>>
>>> Thanks for the replies.  Let me ask a more pointed question now as 
>>> rummaging through the source will probably take me hours.  I'm curious 
>>> about the overloads with the throwable, for instance:
>>>
>>>
>>> logger.error("some message", <some throwable>);
>>>
>>>
>>> What's the expected behavior?  Meaning, what is the logging framework going 
>>> to do with the message and the exception?  I know the message is usually 
>>> output via the message property in the pattern layout.  But what happens 
>>> with the throwable?  Is there some code responsible for constructing a 
>>> message which combines the supplied message with the throwable exception 
>>> message and callstack?
>>>
>>>
>>> I wrote the following simple java sample:
>>>
>>>
>>> import org.apache.logging.log4j.Logger;
>>> import org.apache.logging.log4j.LogManager;
>>>
>>> public class Test
>>> {
>>>  private static final Logger logger = LogManager.getLogger(Test.class);
>>>
>>>  public static void main(String[] args)
>>>  {
>>>       logger.info("entered main");
>>>  try
>>>          {
>>>          throw(new IllegalArgumentException("bad argument"));
>>>          }
>>>  catch(Throwable t)
>>>          {
>>>          logger.error("caught exception", t);
>>>          }
>>>  logger.info("exiting main");
>>>  }
>>> }
>>>
>>>
>>> Here is the log4j2.xml file:
>>>
>>>
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <Configuration status="WARN">
>>>  <Appenders>
>>>      <Console name="Console" >
>>>          <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} 
>>> \
>>> - %msg%n"/>
>>>      </Console>
>>>  </Appenders>
>>>  <Loggers>
>>>  <Root level="info">
>>>          <AppenderRef ref="Console"/>
>>>  </Root>
>>>  </Loggers>
>>> </Configuration>
>>>
>>>
>>> Here is the output to the console when I run the sample:
>>>
>>>
>>> [nick@thinkpad log4j]$ java Test
>>> 16:37:57.681 [main] INFO  Test - entered main
>>> 16:37:57.683 [main] ERROR Test - caught exception
>>> java.lang.IllegalArgumentException: bad argument
>>>  at Test.main(Test.java:13) [log4j/:?]
>>> 16:37:57.689 [main] INFO  Test - exiting main
>>>
>>>
>>> So there does seem to be some code which is combining the message with the 
>>> exception.  Just wondering where that happens.  Now onto my specific 
>>> problem.  We've got someone saying that when they use the error() method 
>>> which takes a string message and an throwable the exception information is 
>>> not making it to our central repository.  We have written our own appender 
>>> and our own layout.  Here is a snippet from our appender:
>>>
>>>
>>> String serializedEvent = (String) getLayout().toSerializable(logEvent);
>>>
>>> Here is a snippet from our layout:
>>>
>>>
>>> String message = logEvent.getMessage().getFormattedMessage();
>>>
>>>
>>> It seems the message above does not include any exception info.  What are 
>>> we doing wrong?
>>>
>>>
>>> Thanks,
>>>
>>> Nick
>>>
>>> ________________________________
>>> From: Remko Popma <remko.po...@gmail.com>
>>> Sent: Friday, November 4, 2016 10:42 AM
>>> To: Log4J Users List
>>> Subject: Re: looking for source
>>>
>>> Sure. Start in AbstractLogger in the API module: 
>>> https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java
> [https://avatars1.githubusercontent.com/u/47359?v=3&s=400]<https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java>
>
> apache/logging-log4j2<https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java>
> github.com
> logging-log4j2 - Mirror of Apache Logging Log4J2
>
>
>> [https://avatars1.githubusercontent.com/u/47359?v=3&s=400]<https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java>
>>  
>> <https://avatars1.githubusercontent.com/u/47359?v=3&s=400]%3Chttps://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java%3E>
>>
>> apache/logging-log4j2<https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java
>>  
>> <https://github.com/apache/logging-log4j2/blob/master/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLogger.java>>
>> github.com <http://github.com/>
>> logging-log4j2 - Mirror of Apache Logging Log4J2
>>
>>
>>>
>>> and at some point you probably also want to look at the concrete subclass 
>>> Logger in the core module: 
>>> https://github.com/apache/logging-log4j2/blob/master/log4j-core/src/main/java/org/apache/logging/log4j/core/Logger.java
>> [https://avatars1.githubusercontent.com/u/47359?v=3&s=400]<https://github.com/apache/logging-log4j2/blob/master/log4j-core/src/main/java/org/apache/logging/log4j/core/Logger.java>
>>
>> apache/logging-log4j2<https://github.com/apache/logging-log4j2/blob/master/log4j-core/src/main/java/org/apache/logging/log4j/core/Logger.java>
>> github.com
>> logging-log4j2 - Mirror of Apache Logging Log4J2
>>
>>
>>>
>>> Hope this helps to get you started.
>>>
>>> It may be easier to use an IDE and check out the whole project 
>>> (https://logging.apache.org/log4j/2.x/source-repository.html).
> Log4j – Source Repository - Apache Log4j 
> 2<https://logging.apache.org/log4j/2.x/source-repository.html>
> logging.apache.org
> Access from Behind a Firewall. Refer to the documentation of the SCM used for 
> more information about access behind a firewall.
>
>
>> Log4j - Source Repository - Apache Log4j 
>> 2<https://logging.apache.org/log4j/2.x/source-repository.html>
> Log4j – Source Repository - Apache Log4j 
> 2<https://logging.apache.org/log4j/2.x/source-repository.html>
> logging.apache.org
> Access from Behind a Firewall. Refer to the documentation of the SCM used for 
> more information about access behind a firewall.
>
>
>> logging.apache.org
>> Access from Behind a Firewall. Refer to the documentation of the SCM used 
>> for more information about access behind a firewall.
>>
>>
>>> Log4j - Source Repository - Apache Log4j 
>>> 2<https://logging.apache.org/log4j/2.x/source-repository.html 
>>> <https://logging.apache.org/log4j/2.x/source-repository.html>>
> Log4j – Source Repository - Apache Log4j 
> 2<https://logging.apache.org/log4j/2.x/source-repository.html 
> <https://logging.apache.org/log4j/2.x/source-repository.html>>
> logging.apache.org <http://logging.apache.org/>
> Access from Behind a Firewall. Refer to the documentation of the SCM used for 
> more information about access behind a firewall.
>
>
>> Log4j - Source Repository - Apache Log4j 
>> 2<https://logging.apache.org/log4j/2.x/source-repository.html 
>> <https://logging.apache.org/log4j/2.x/source-repository.html>>
> Log4j – Source Repository - Apache Log4j 
> 2<https://logging.apache.org/log4j/2.x/source-repository.html 
> <https://logging.apache.org/log4j/2.x/source-repository.html>>
> logging.apache.org <http://logging.apache.org/>
> Access from Behind a Firewall. Refer to the documentation of the SCM used for 
> more information about access behind a firewall.
>
>
>> logging.apache.org <http://logging.apache.org/>
>> Access from Behind a Firewall. Refer to the documentation of the SCM used 
>> for more information about access behind a firewall.
>>
>>
>>> logging.apache.org <http://logging.apache.org/>
>>> Access from Behind a Firewall. Refer to the documentation of the SCM used 
>>> for more information about access behind a firewall.
>>>
>>>
>>>
>>> Enjoy!
>>> Remko
>>>
>>> Sent from my iPhone
>>>
>>>> On 4 Nov 2016, at 23:29, Nicholas Duane <nic...@msn.com> wrote:
>>>>
>>>> I'm not that familiar with java and java conventions, package names, etc.  
>>>> I'm trying to find the source for log4j2's implementation of 
>>>> logger.error(String, Throwable);.  Can someone point me to that?  I was 
>>>> looking around here:
>>>>
>>>>
>>>> https://git-wip-us.apache.org/repos/asf?p=logging-log4j2.git;a=tree;hb=refs/heads/master
>>>>
>>>>
>>>> But couldn't seem to find what I was looking for.
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Nick
>>
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