title: java.io.FileNotFoundException with FileWriter
body: <p>The following line</p>
  
  <pre><code>FileWriter fw = new FileWriter("/log0.txt");
  </code></pre>
  
  <p>throws:<br>
  <code>java.io.FileNotFoundException: /log0.txt (Read-only file system)</code></p>
  
  <p>I'm testing this on device and "USB storage"  is off. Any idea why this happens?</p>