Log4j does not print stack trace

Question

I catch NullPointerException but log4j does not print stack trace, I aspect number of line of exception occurred etc. what is wrong?

My log

20110412-101042,317[ Timer-7][R] Exception while processing for value: abc.                  [xyz.Dummy]
java.lang.NullPointerException

log4j.property file

log4j.rootCategory=ERROR, logfile
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%-5p %r [%t] : %m%n
log4j.appender.logfile=org.apache.log4j.RollingFileAppender
log4j.appender.logfile.File=my_application.log
log4j.appender.logfile.Append=true
log4j.appender.logfile.MaxBackupIndex =10
log4j.appender.logFile.MaxFileSize=40000KB
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d{yyyyMMdd-HHmmss,SSS}[%8.8t][%.1p] %-70m[%c{2}]%n

My snippet code

String value;
try {
   value = "abc";
   //... lots for code
}catch(Exception e) {
   logger.error("Exception while processing for value: " + value + ". ", e);
}

Answer 1

The problem is the %-70m in your Layout. It truncates the message, and therefore does not reach the stacktrace. Use %m as usual instead.

Even Better: Write a custom layout, this will work as you want.

Answer 2

Your code only shows the exception message.If you want to see stack trace ,you must use something like that:

How to store printStackTrace into a string

Try to use that one instead of exception 'e'.

Answer 3

Anybody who wants to print the line number to know where null pointer exception occurred without printing the full stacktrace, please try like below:

try {
 // your code here
}catch(NullPointerException ne){
 System.out.println("NullPointerException : LineNumber:"+ne.getStackTrace()[0].getLineNumber()+" : "+ne);

}