title: FileInputStream NullpointerException
body: <p>I'm trying to read a properties file <code>/res/version.num</code>. 
  But all I get is a NPE.</p>
  
  <pre><code>try {
      URL url = getClass().getResource("/res/version.num");
      logger.writeLog(JammEnum.INFO, "version.num path: " + url.getPath());
      File prop_file = new File(url.getPath());
      FileInputStream fis = new FileInputStream(prop_file);
      prop.load(fis);
      fis.close();
  } 
  catch (FileNotFoundException e) {
      logger.writeLog(JammEnum.ERROR, "File not found: version.num");
      e.printStackTrace();
  } 
  catch (IOException e) {
      logger.writeLog(JammEnum.ERROR, "Cannot read version.num");
      e.printStackTrace();
  }
  </code></pre>
  
  <p>The output is:</p>
  
  <pre><code>(II) - version.num path: /home/andreas/Programmieren/Java/Jamm/bin/res/version.num
  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
      at jamm.gui.InfoGui.&lt;init&gt;(InfoGui.java:83)
      at jamm.gui.FinanzmanagerGui$ButtonInfoListener.actionPerformed(FinanzmanagerGui.java:553)
      at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
      at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
      at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
      at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
      at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
      at java.awt.Component.processMouseEvent(Component.java:6504)
      at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
      at java.awt.Component.processEvent(Component.java:6269)
      at java.awt.Container.processEvent(Container.java:2229)
      at java.awt.Component.dispatchEventImpl(Component.java:4860)
      at java.awt.Container.dispatchEventImpl(Container.java:2287)
      at java.awt.Component.dispatchEvent(Component.java:4686)
      at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
      at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
      at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
      at java.awt.Container.dispatchEventImpl(Container.java:2273)
      at java.awt.Window.dispatchEventImpl(Window.java:2713)
      at java.awt.Component.dispatchEvent(Component.java:4686)
      at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
      at java.awt.EventQueue.access$000(EventQueue.java:101)
      at java.awt.EventQueue$3.run(EventQueue.java:666)
      at java.awt.EventQueue$3.run(EventQueue.java:664)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
      at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
      at java.awt.EventQueue$4.run(EventQueue.java:680)
      at java.awt.EventQueue$4.run(EventQueue.java:678)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
      at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
      at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
      at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
      at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
      at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
      at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
  </code></pre>
  
  <p>Line 83 is: FileInputStream fis = new FileInputStream(prop_file);</p>
  
  <p>The path for the file is logged correct. But why do I get this Exception?</p>