title: Getting error when trying to add SkyEpub reader
body: <p>This is the code that i have tried to implement SkyEpub Reader and adding books to it.</p>
  
  <pre><code>public boolean makeBooksDirectory() {
          boolean res;
          String filePath = new String(getFilesDir().getAbsolutePath() + "/books");
          Log.d("Debug", filePath);
          File file = new File(filePath);
          if (!file.exists()) {
              res = file.mkdirs();
              Log.d("Land",file.getPath());
          }else {
              res = false;
          }
          return res;
      }
  
      public boolean fileExists(String fileName) {
          boolean res;
  
          String pureName = this.removeExtention(fileName);
          String targetDirectory = getFilesDir().getAbsolutePath() + "/books/"+pureName;
          String targetPath = targetDirectory+"/"+ fileName;
  
          File file = new File(targetPath);
          debug(file.getAbsolutePath());
  
          if (file.exists()) res = true;
          else  res = false;
          return res;
      }
  </code></pre>
  
  <p>But When i tried to run it, it shows following error. I cant understand if should i need to make book folder anywhere?</p>
  
  <p>Error:</p>
  
  <pre><code>I/Timeline: Timeline: Activity_launch_request  D/Debug: /data/user/0/com.App/files/books
  
  08-30 19:43:34.425 15819-15819/com.App D/EPub: faild to make books directory
  
  08-30 19:43:34.457 15819-15819/com.App D/PhoneWindow: notifyNavigationBarColor, color=0x: ff000000, token: android.view.ViewRootImplAO$WEx@4064635
  
  08-30 19:43:34.629 15819-15819/com.App V/ViewRootImpl: Contents drawing finished : com.App/com.App.activities.EPubActivity
  08-30 19:43:34.671 15819-15877/com.App E/Surface: getSlotFromBufferLocked: unknown buffer: 0xa5d062e0
  </code></pre>