Logging is processed by the logger twice

Question

I have a web-application which I want to log for. There is some default logging provided by a logging.properties file, which I am unable to influence. It logs the server startup, shutdown, etc.

These are examples of such logs (normal ones, nothing wrong here):

2016/01/22 12:25:10  INFO (ApplicationContext.java:671 [ServerService Thread Pool -- 64]) - Initializing Spring root WebApplicationContext
2016/01/22 12:25:13  INFO (ConfigureListener.java:202 [ServerService Thread Pool -- 64]) - Initializing Mojarra 2.1.28-jbossorg-6  for context '/MyServices'
2016/01/22 12:25:15  INFO (DeploymentHandlerUtil.java:137 [ServerService Thread Pool -- 28]) - JBAS015859: Deployed "MyServices.war" (runtime-name : "MyServices.war")
2016/01/22 12:25:15  INFO (BootstrapListener.java:93 [Controller Boot Thread]) - JBAS015874: JBoss EAP 6.4.0.GA (AS 7.5.0.Final-redhat-21) started in 27257ms - Started 485 of 520 services (63 services are lazy, passive or on-demand)

Now I also have logging in my application for my own methods, specified using:

private static final org.slf4j.Logger LOG = org.slf4j.LoggerFactory.getLogger(PropertiesValues.class);
...
LOG.info("Properties loaded.");

The problem is that when these logs are hit, the causes double logging, where each line has two timestamps, two log levels, and two sources, such as:

2016/01/22 11:50:49  INFO (AbstractLoggingWriter.java:71 [ServerService Thread Pool -- 111]) - 2016/01/22 11:50:49  INFO (EnvironmentLoader.java:128 [ServerService Thread Pool -- 111]) - Starting Shiro environment initialization.
2016/01/22 11:50:49  INFO (AbstractLoggingWriter.java:71 [ServerService Thread Pool -- 111]) - 2016/01/22 11:50:49  INFO (EnvironmentLoader.java:141 [ServerService Thread Pool -- 111]) - Shiro environment initialized in 125 ms.
...
2016/01/22 11:51:20  INFO (AbstractLoggingWriter.java:71 [http-localhost/127.0.0.1:8443-6]) - 2016/01/22 11:51:20  INFO (PropertiesValues.java:101 [http-localhost/127.0.0.1:8443-6]) - Properties loaded.

Note the logs are being processed twice. That is - Each line that would be printed is run through the logger again, resulting in two timestamps, two log levels, and two sources. I can get around this by changing the last line in my log4j.properties file:

log4j.rootLogger=INFO, STDOUT
log4j.additivity.rootLogger=false
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.Target=System.out
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.ConversionPattern=%d{yyyy/MM/dd HH:mm:ss} %5p (%F:%L [%t]) - %m%n

To only be %m but I feel that this is a poor solution, and results in the source being shown as AbstractLoggingWriter.java:71 for everything.

Is there a way to make it so that my logs show the correct method and line number, and are formatted how I choose, rather than the server? At the same time, I also don't want to lose the logging provided by the server.

My Maven dependencies are:

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.5</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.5</version>
</dependency>
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>

Answer 1

We had the same problem with our application, we fixed that by adding the following in jboss-deployment-structure.xml to WEB-INF in the web application:

<?xml version="1.0" encoding="utf-8"?>
<jboss-deployment-structure>
   <deployment>
       <!-- Exclusions allow you to prevent the server from automatically adding some dependencies -->
       <exclude-subsystems>  
           <subsystem name="logging" />
       </exclude-subsystems>  
   </deployment>
</jboss-deployment-structure>

Answer 2

It's hard to say exactly what's happening, but I'll try to guess. I see you use JBoss, it uses commons-logging to log events. You set log4j to output to stdout. Possibly Logger from JBoss grabs what's being sent to stdout and logs it, so you have a message decorated twice.

Try to use org.jboss.logging.Logger from JBoss instead of slf4j Or as a dirty trick you may try to switch off log4j output by adding log4j.appender.STDOUT.Threshold=off to log4j.properties