Menu
▾
▴
#24 stdout, stderr redirect capability
I'm migrating from some homegrown scripts for
linux/win32 to java service wrapper and I used to
redirect STDOUT and STDERR to simple files by appending
> app.output 2> app.errors to the command line.
It appears I cant to that anymore? It would be nice if
maybe there were some extra .conf settings to support this?
Logged In: YES
user_id=228081
You can get this functionality by redirecting the System.out
and System.err Print Streams from within the JVM.
Create your own class that extends PrintStream and simply
writes anything printed to the stream to a specific file.
Then call System.setOut and System.setErr with instances of
your class.
I used this method a long time ago to create a simple
logging tool. Before all the current logging tools were
available.
Overriding the output PrintStreams should allow you to
capture pretty much all of your JVM output. I don't think
it will capture any fatal JVM crash errors as they are
printed to the error stream as the JVM is dying. But they
would be captured in the wrapper.log file still.
Let me know if this will meet your needs. You are unable
to redirect the output and error output using redirects as
you described above because the Wrapper is launching the
Java process directly rather than using a shell. This means
that shell functions are not available.
It would be possible to implement what you are asking for
within the Wrapper but would involve adding new properties
to the wrapper.conf for each output stream. I would then
also need properties to configure whether or not the output
was also sent to the console, wrapper log file, syslog
etc... I would like to keep the logging configuration from
getting any more complicated. so am hoping that the above
work around will work for you.
It is really designed to make it possible to log fatal
errors and basic startup messages that may not be possible
to log from within the JVM. Writing yet another complicated
logging tool is something that I would like to avoid if
possible.
Cheers,
Leif
Logged In: YES
user_id=53112
I'd like this feature too.
Probably the best thing would be having "jvm-out 1" and
"jvm-err 1" as log prefix mantaining a single log file that
could be split using grep o a similar command if needed.
Are there plans to implement this?
Logged In: YES
user_id=228081
This is still on my todo list. It will involve a rework of
the way output is piped from the JVM to the Wrapper proess
however and is thus not as simple as one would think. Not
forgotten though.
Cheers,
Leif
Logged In: YES
user_id=1467052
I know an old feature, but bumping a little. My take on this
would be to have the System.out to be logged as
INFO | jvm 1 | 2006/03/14 15:19:28 | .....
and the System.err to be logged as
ERROR | jvm 1 | 2006/03/14 15:19:28 | .....
The reason I argue for this instead of jvm-out and jvm-err,
is that you should be able to see more clearly (i.e. caps
and start of line) those lines in the log which are errors,
such as Exception dumps, and custom err messages. Plus I
think its a bit easier to write a RegEx testing on the start
of a line, rather that finding jvm-err in the middle of a
line. (I know I know, I can figure it out, but its just
easier :-)).
Thanks Leif,
David Hayes