log4j socket appender

From:

doug.farrell@gmail.com

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 19 Sep 2014 13:34:22 -0700 (PDT)

Message-ID:

<64807899-4e1f-4a12-853b-ad521a27ec48@googlegroups.com>

Hi all,

I'm not a Java developer (work primarily in Python and JavaScript), but I n=
eed some help. I've written a logging server that handles log records sent =
via UDP, and I'd like to do the same thing with Java. I've got a Java test =
harness built that looks like this:

import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;

public class HelloWorld {
=09
    /* get an actual logger */
    private static final Logger logger = LogManager.getLogger("HelloWorld");
    =09
    public static void main(String[] args) {
        logger.info("Info level message");
    }
}

and has a log4j.xml configuration file that looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
  <Appenders>
    <Console name="STDOUT" target="SYSTEM_OUT">
      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} =
- %msg%n"/>
    </Console>
    <Socket name="SOCKET" host="localhost" port="9023" protocol="UD=
P">
     <SerializedLayout />
    </Socket>
  </Appenders>
  <Loggers>
    <Root level="info">
      <AppenderRef ref="STDOUT"/>
      <AppenderRef ref="SOCKET"/>
    </Root>
  </Loggers>
</Configuration>

This works and sends log records from the Java test program to my Python lo=
gging server. However, I can't figure out what the format of the data recei=
ved by the Python logging server is? This is the data I get back in my hand=
ler:

'\xac\xed\x00\x05sr\x00>org.apache.logging.log4j.core.impl.Log4jLogEvent$Lo=
gEventProxy\x9c\xed\x0f]p\xda*\x16\x02\x00\rZ\x00\x0cisEndOfBatchZ\x00\x12i=
sLocationRequiredJ\x00\ntimeMillisL\x00\ncontextMapt\x00\x0fLjava/util/Map;=
L\x00\x0ccontextStackt\x005Lorg/apache/logging/log4j/ThreadContext$ContextS=
tack;L\x00\x05levelt\x00 Lorg/apache/logging/log4j/Level;L\x00\nloggerFQCNt=
\x00\x12Ljava/lang/String;L\x00\nloggerNameq\x00~\x00\x04L\x00\x06markert\x=
00!Lorg/apache/logging/log4j/Marker;L\x00\x07messaget\x00*Lorg/apache/loggi=
ng/log4j/message/Message;L\x00\x06sourcet\x00\x1dLjava/lang/StackTraceEleme=
nt;L\x00\nthreadNameq\x00~\x00\x04L\x00\x0bthrownProxyt\x003Lorg/apache/log=
ging/log4j/core/impl/ThrowableProxy;xp\x00\x01\x00\x00\x01H\x8f\x9d\xfb>sr\=
x00\x1ejava.util.Collections$EmptyMapY6\x14\x85Z\xdc\xe7\xd0\x02\x00\x00xps=
r\x00>org.apache.logging.log4j.ThreadContext$EmptyThreadContextStack\x00\x0=
0\x00\x00\x00\x00\x00\x01\x02\x00\x00xpsr\x00\x1eorg.apache.logging.log4j.L=
evel\x00\x00\x00\x00\x00\x18 \x1a\x02\x00\x03I\x00\x08intLevelL\x00\x04name=
q\x00~\x00\x04L\x00\rstandardLevelt\x00,Lorg/apache/logging/log4j/spi/Stand=
ardLevel;xp\x00\x00\x01\x90t\x00\x04INFO~r\x00*org.apache.logging.log4j.spi=
..StandardLevel\x00\x00\x00\x00\x00\x00\x00\x00\x12\x00\x00xr\x00\x0ejava.la=
ng.Enum\x00\x00\x00\x00\x00\x00\x00\x00\x12\x00\x00xpt\x00\x04INFOt\x00+org=
..apache.logging.log4j.spi.AbstractLoggert\x00\nHelloWorldpsr\x00.org.apache=
..logging.log4j.message.SimpleMessage\x8btM0`\xb7\xa2\xa8\x02\x00\x01L\x00\x=
07messageq\x00~\x00\x04xpt\x00\x12Info level messagesr\x00\x1bjava.lang.Sta=
ckTraceElementa\t\xc5\x9a&6\xdd\x85\x02\x00\x04I\x00\nlineNumberL\x00\x0ede=
claringClassq\x00~\x00\x04L\x00\x08fileNameq\x00~\x00\x04L\x00\nmethodNameq=
\x00~\x00\x04xp\x00\x00\x00\x0cq\x00~\x00\x17t\x00\x0fHelloWorld.javat\x00\=
x04maint\x00\x04mainpy'

I can see the data I want in there, but don't know how to parse this. Any h=
ints, pointers or suggestions would be most welcome!

Thanks in advance,
Doug