how to find the jar file containing a class definition? [closed]

Question

Is there a tool, plugin, or script I can use to find a java class in a bunch of jar files?

Very often I inherit code that complains about a class that doesn't exist, and it is just because the jar file is not included in the classpath. But, in what jar file(s) is the class? I may not have the JAR (so I have to search online), or adding a JAR to the classpath could create a duplicated class definition problem.

I obviously would prefer an eclipse plugin, but I'm open to any piece of software that works with Windows.

I know... Windows is not my choice, but that's what I got to work with.

Thanks!

Luis

P.S. Thank you for your answers. After reviewing some responses, I became aware that I should have explained better my scenario. We had a library of downloaded or created JAR files, but sometimes the class would be online somewhere.

Answer 1

(This is an improvement over the script I had in previous versions of the answer as it produces much cleaner output at the price of some awk special/ugly quoting.)

I've built a script (findinjars) which does just that.

#!/usr/bin/env bash if [[ ($# -ne 1) && ($# -ne 2) ]] then     echo "usage is $0 <grep pattern to look for in 'jar tvf' output> [<top-of-dir-tree> or, if missing, current dir]" else     THING_TO_LOOKFOR="$1"     DIR=${2:-.}     if [ ! -d $DIR ]; then         echo "directory [$DIR] does not exist";         exit 1;     fi     find "$DIR" -iname \*.jar | while read f ; do (jar tf $f | awk '{print "'"$f"'" "  " $0}' | grep -i "$THING_TO_LOOKFOR") ; done fi 

you can then invoke it with:

$findinjars a.b.c.d.Class [directoryTreeRoot or, if missing, current dir] 

or just

$findinjars partOfClassName [directoryTreeRoot or, if missing, current dir] 

Dot characters in the fully qualified class name will be interpreted in the regexp sense of 'any character' but that's not a big deal since this is a heuristics utility (that's why it's case-insensitive too BTW). Usually I don't bother with the full class name and just type part of it.

Answer 2

In the same lines as BalusC's answer (I can't post comment yet nor link 2 urls, no reputation :( ), you can find a jar thanks to these 2 jar finder engines: - http://www.jarfinder.com/ - findjar