Search for a string within files within jars - stolen from http://www.linuxquestions.org/questions/linux-newbie-8/searching-contents-of-class-file-within-jar-for-strings-705087/

search-in-jar.sh

#!/usr/bin/env bash
find . -iname '*.jar' -print | while read jar; do
  echo "$jar:"
  unzip -qq -l $jar | sed 's/.* //' | while read cls; do
    unzip -c $jar $cls | grep -q 'Tag read' && echo "   "$cls
  done
done