Best Practices from Oracle Development's A‑Team
-
Diagnostics & Troubleshooting,
Products and Services /
Operating Systems
February 27, 2011
Finding which JAR contains a class – again!
I posted a few days ago about finding which JAR file contains a class file – something I often want to do. My friend Chris Johnson promptly posted a better version here with caching – thanks Chris!
Chris said I inspired him to finish his script and in return he has inspired me to improve it further. As I often work with JAR files in a development environment, and often a lot of them, the search can take a while, so the caching is great. But – those files can change over time, so I need the cache to be kept up to date.
Here is an updated version of Chris’ version that will update the cache if a JAR file is newer than the cache:
#!/bin/sh TARGET="$1" CACHEDIR=~/.jarfindcache # prevent people from hitting Ctrl-C and breaking our cache trap 'echo "Control-C disabled."' 2 if [ ! -d $CACHEDIR ]; then mkdir $CACHEDIR fi for JARFILE in `find $PWD -name "*jar"` do CACHEFILE=$CACHEDIR$JARFILE if [ ! -s $CACHEFILE ]; then mkdir -p `dirname $CACHEFILE` nohup jar tvf $JARFILE > $CACHEFILE # if the jar file has been updated, cache it again elif [ $JARFILE -nt $CACHEFILE ]; then nohup jar tvf $JARFILE > $CACHEFILE fi grep $TARGET $CACHEFILE > /dev/null if [ $? == 0 ] then echo "$TARGET is in $JARFILE" fi done
P.S. If you are running this on Ubuntu (or Debian), like me, you better make that first line a bit more explicit:
#!/bin/bash
Enjoy!