title: How to extract files from .obb file?
body: <p>in my application I downloaded the expansion file at Android->obb->packagename->main.1.packagename.obb .
  Can someone explain to me, even with the sample code how to extract my files from it ?</p>
  
  <p>I tried to use the APK Expansion Zip Library as :</p>
  
  <pre><code>ZipResourceFile expansionFile = APKExpansionSupport.getAPKExpansionZipFile(MainActivity.this, 3, 0);  
  for (ZipResourceFile.ZipEntryRO entry : expansionFile.getAllEntries())
  Log.d("",entry.mFileName);
  InputStream input = expansionFile.getInputStream(Environment.getExternalStorageDirectory().toString()
                              + "/sdcard/Android/obb/com.example.project/main.3.com.example.project.obb/obb/file.zip/file.apk");
  </code></pre>
  
  <p>But expansionFile is always null.
  The .obb file was created with Jobb, used on the folder obb/file.zip .</p>