title: Replacing and Patching classes in Android projects
body: <p>For a Android project, I need to use an existing library packaged as a JAR. </p>
  
  <p>This JAR however contains a class which performs Base64 encoding using javax.xml.DatatypeConverter.</p>
  
  <p>To use the library on Android, I need to remove this class from the JAR, and replace it with a class which uses the Android Base64 implementation.</p>
  
  <p>One option is to delete the incompatible class from JAR directly, and provide the Android replacement in my Android Studio project. This works as expected. </p>
  
  <p>Question: are there better ways to 'replace' (hide) the original class, which do not require manipulation of the JAR? </p>