title: can't load jdbc driver class PostgreSQL + NIFI
body: <p>Start working with Nifi and this is my first exercise.</p>
  
  <p>So trying to put a csv file in a Postgres table. I defined my data base driver as shown in the picture.</p>
  
  <p>The error is: </p>
  
  <blockquote>
    <p>can't load jdbc driver class</p>
  </blockquote>
  
  <p>in my log file I have this message: </p>
  
  <pre><code>ERROR [StandardProcessScheduler Thread-1] o.a.n.c.s.StandardControllerServiceNode DBCPConnectionPool[id=c25f8f91-0161-1000-a496-8910832bdbd8] F$
  org.apache.nifi.reporting.InitializationException: Can't load Database Driver
          at org.apache.nifi.dbcp.DBCPConnectionPool.getDriverClassLoader(DBCPConnectionPool.java:249)
          at org.apache.nifi.dbcp.DBCPConnectionPool.onConfigured(DBCPConnectionPool.java:198)
          at sun.reflect.GeneratedMethodAccessor437.invoke(Unknown Source)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:498)
          at org.apache.nifi.util.ReflectionUtils.invokeMethodsWithAnnotations(ReflectionUtils.java:137)
          at org.apache.nifi.util.ReflectionUtils.invokeMethodsWithAnnotations(ReflectionUtils.java:125)
          at org.apache.nifi.util.ReflectionUtils.invokeMethodsWithAnnotations(ReflectionUtils.java:70)
          at org.apache.nifi.util.ReflectionUtils.invokeMethodsWithAnnotation(ReflectionUtils.java:47)
          at org.apache.nifi.controller.service.StandardControllerServiceNode$2.run(StandardControllerServiceNode.java:409)
          at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
          at java.util.concurrent.FutureTask.run(FutureTask.java:266)
          at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
          at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
          at java.lang.Thread.run(Thread.java:748)
  Caused by: java.lang.ClassNotFoundException: org.postgresql.Driver
  </code></pre>