title: Config files needed for SLF4J bridging
body: <p>I am writing a Java app that will use SLF4J to handle logging with a runtime binding of JUL (Java Utils Logging). Thus my classpath will have <code>slf4j-api-1.6.4.jar</code> as well as <code>slf4j-jdk14-1.6.4.jar</code> on it.</p>
  
  <p>JUL can be configured via <code>logging.properties</code> so I will need that on my classpath too.</p>
  
  <p>In order to make sure that all my 3rd party dependencies log to the same JUL configuration, I am planning on putting all of the following bridges on my classpath as well:</p>
  
  <ul>
  <li><code>jcl-over-slf4j-1.6.4.jar</code></li>
  <li><code>log4j-over-slf4j-1.6.4.jar</code></li>
  </ul>
  
  <p>JCL is configured via <code>commons-logging.properties</code> and Log4J is configured via <code>log4j.properties</code>.</p>
  
  <p>My question: <strong>do I need to put <code>commons-logging.properties</code> and <code>log4j.properties</code> on my classpath, or is this unnecessary because of the SLF4J bridges?</strong></p>
  
  <p>I'm 90% sure I don't have to, but need a sanity check here! My theory is that the bridges replace the normal JCL/Log4J classes with stubs that just blindly call SLF4J API calls.</p>
  
  <p>These SLF4J API calls in turn, like my code will do, use whatever implementations they bind to at runtime. Since the binding in my case is JUL, only a <code>logging.properties</code> file should be required.</p>
  
  <p>But I'm not a logging expert, and I'd rather be safe than sorry. So do I need these extra config files, and if so, please explain why so I can better understand how SLF4J works! Thanks in advance!</p>