Log4J conversion specifier "%l" not printing the whole stack trace

Question

I am trying to send an email in case error occurs in our project. For this we are using Log4j's SMTPAppender. I am running my project in the development mode and trying to get the full stack trace of the error by using following ConversionPattern in SMTPAppender :

<param name="ConversionPattern" 
    value="[%d{ISO8601}] [%t] [%5p] [%c ] %n %m %l %X{config}"/>

I am throwing error as follows:

try {
  throw new Exception(" To get the MDC values !!!");
} catch (Exception e)
{
  LOGGER.error(" To get the MDC values !!!", e);
}

%m is replaced by the text To get the MDC values !!! but %l (lower-case L) is printing the fully qualified class name of the caller issuing the logging request with line number (just like %c do, with one difference that %c never prints the line number while %l does).

What could be the correct way to get the stack trace and why %l is not getting the whole stack trace ?

Answer 1

%l is used to output location information of the caller which generated the logging event. it si snot print whole stacktrace. you can add these lines of code in your catch block.

catch (Exception e) {
            CharArrayWriter cw = new CharArrayWriter();
            PrintWriter w = new PrintWriter(cw);
            e.printStackTrace(w);
            w.close();
            String trace = cw.toString();
     LOGGER.error(" To get the MDC values !!!",trace);
}