For uniform logging in Simantics Platform [ The Simple Logging Facade for Java](http://www.slf4j.org/) (`org.slf4j.api`) and [Logback Project](http://logback.qos.ch/) (`ch.qos.logback.classic`) is included in Simantics SDK. To use the SLF4J logging API just include the following bundle in your own plugin's `MANIFEST.MF` dependencies:

    Require-Bundle: ..,
    org.slf4j.api

An example usage of logging inside your own java code is presented below:

~~~
 1: import org.slf4j.Logger;
 2: import org.slf4j.LoggerFactory;
 3:
 4: public class Wombat {
 5:  
 6:   private static final Logger LOGGER = LoggerFactory.getLogger(Wombat.class);
 7:   private Integer t;
 8:   private Integer oldT;
 9:
10:   public void setTemperature(Integer temperature) {
11:    
12:     oldT = t;        
13:     t = temperature;
14:
15:     LOGGER.debug("Temperature set to {}. Old temperature was {}.", t, oldT);
16:
17:     if(temperature.intValue() > 50) {
18:       LOGGER.info("Temperature has risen above 50 degrees.");
19:     }
20:   }
21: }
~~~

The SLF4J Manual can be found here: http://www.slf4j.org/manual.html

## Configuring Logback

By default bundle `org.simantics.logback.configuration` contains the `logback.xml` configuration file in which the logging format and different appenders are defined. By default it looks like this:

~~~
<?xml version="1.0" encoding="UTF-8"?>
<configuration>

  <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
    <!-- encoders are assigned the type ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
    <encoder>
      <pattern>%-5p [%d] %c: %m%n%rEx</pattern>
    </encoder>
  </appender>

  <appender name="async-console" class="ch.qos.logback.classic.AsyncAppender">
    <appender-ref ref="console" />
  </appender>

  <root level="debug">
    <appender-ref ref="async-console" />
  </root>
</configuration>
~~~

This configuration creates a single ''asynchronous'' `ConsoleAppender` which prints all the logging to `System.out` by. An example output would look like:

    INFO  [2016-09-23 15:56:25,498] org.simantics.workbench.internal.SimanticsWorkbenchAdvisor: startPlatform finished

It is possible to override this default configuration be giving a VM-argument for the application in format:

    -Dlogback.configurationFile="C:\logbacs\logback.xml"

For detailed information see [Logback manual](http://logback.qos.ch/manual/).