title: Prevent Weblogic 12c from using system's slf4j binding
body: <p>We're building new systen using slf4j as logging facade. When deploying on newly Weblogic 12c, we found this error on console log:</p>
  
  <pre><code>SLF4J: Class path contains multiple SLF4J bindings.
  SLF4J: Found binding in [jar:file:/opt/Oracle/Middleware2/modules/org.slf4j.jdk14_1.6.1.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
  SLF4J: Found binding in [zip:/opt/Oracle/Middleware2/user_projects/domains/m3/servers/AdminServer/tmp/_WL_user/test/t030q4/war/WEB-INF/lib/slf4j-log4j12-1.6.4.jar!/org/slf4j/impl/StaticLoggerBinder.class]
  </code></pre>
  
  <p>after googling, we found that this is just a warning, slf4j will bind first found logger, which in this case is weblogic's system logger framework. Is there any way to make it bind to logging framework in our WAR file? Having &lt;prefer-web-inf-classes&gt; in weblogic.xml does not help</p>