title: How to convert .jar 1.7 to .jar 1.6
body: <p>I've updated Dropbox API framework from 2.0.1 to current 3.1.2 in my android app. While packing my app i'm getting multiple errors like:</p>
  
  <blockquote>
    <p>[INFO] trouble processing: [INFO] bad class file magic (cafebabe) or
    version (0033.0000) [INFO] ...while parsing
    com/dropbox/sync/android/DbxStringValue.class [INFO] ...while
    processing com/dropbox/sync/android/DbxStringValue.class [INFO]</p>
  </blockquote>
  
  <p>It <a href="https://stackoverflow.com/questions/26355284/java-lang-noclassdeffounderror-com-dropbox-sync-android-dbxaccountmanager">seems</a> that files are compiled by jdk 1.7 but i'm still using jdk 1.6 and i would not like to update to jdk 1.7 (to avoid new bugs and incompatibilities).</p>
  
  <p>How to convert .jar 1.7 to .jar 1.6?</p>