title: Create nested folders into internal storage
body: <p>I am currently working with <strong>internal storage.</strong> i want to create multiple folders like <strong>mainFolder/subFolder/fileName.</strong></p>
  
  <p>i already prepare lot of tutorials and i wouldn't find the best solution.. And i am also getting error <strong>java.io.FileNotFoundException: open failed: EISDIR (Is a directory).</strong></p>
  
  <p><strong><em>My query was</em></strong></p>
  
  <ul>
  <li>What is this error? <em>any one can please explain this</em>.</li>
  <li>How to create folders  in internal storage.</li>
  </ul>