List contents of multiple jar files

Question

I am searching for a .class file inside a bunch of jars.

jar tf abc.jar 

works for one file. I tried

find -name "*.jar" | xargs jar tf

prints nothing. The only solution I can think of, is unzip all, then search. Is there a better way? I'm on LUnix.

Edit: When scanning many jars, it is useful to print the jar file name along with the class. This method works well:

find . | grep jar$ | while read fname; do jar tf $fname | grep SchemaBuilder && echo $fname; done

Sample output produced:

  1572 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder$1.class
  1718 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder$2.class
 42607 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder.class
./XmlSchema-1.3.2.jar
  1572 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder$1.class
  1718 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder$2.class
 42607 Wed Jul 25 10:20:18 EDT 2007 org/apache/ws/commons/schema/SchemaBuilder.class
./XmlSchema.jar

Solution 1

You need to pass -n 1 to xargs to force it to run a separate jar command for each filename that it gets from find:

find -name "*.jar" | xargs -n 1 jar tf

Otherwise xargs's command line looks like jar tf file1.jar file2.jar..., which has a different meaning to what is intended.

A useful debugging technique is to stick echo before the command to be run by xargs:

find -name "*.jar" | xargs echo jar tf

This would print out the full jar command instead of executing it, so that you can see what's wrong with it.

Solution 2

I faced a similar situation where I need to search for a class in a list of jar files present in a directory. Also I wanted to know from which jar file the class belongs to. I used this below code snippet(shell script) and found out to be helpful. Below script will list down the jar files that contains the class to be searched.

#!/bin/sh
LOOK_FOR="codehaus/xfire/spring"
for i in `find . -name "*jar"`
do
  echo "Looking in $i ..."
  jar tvf $i | grep $LOOK_FOR > /dev/null
  if [ $? == 0 ]
  then
    echo "==> Found \"$LOOK_FOR\" in $i"
  fi
done

Shell script taken from : http://alvinalexander.com/blog/post/java/shell-script-search-search-multiple-jar-files-class-pattern

Solution 3

You can also use -exec option of find

find . -name "*.jar" -exec jar tf {} \;

Solution 4

Here's what I use in Cygwin. It supports section headers per jar file as requested above.

find . -name "*.jar" \
 -exec echo ======\ {}\ ====== \; \
 -exec /c/Program\ Files/Java/jdk1.7.0_45/bin/jar.exe tf {} \; | less

For *nix, drop the ".exe":

find . -name "*.jar" \
 -exec echo ======\ {}\ ====== \; \
 -exec jar tf {} \; | less

View more solutions

Comments

[Lucas]

Your Edit is exactly what i was looking for. Thanks

[im8bit]

Excellent tip with the "echo"

[Abhijit Gaikwad]

can you please modify command find -name "*.jar" | xargs -n 1 jar tf to show which file's contents are being show?

[mjuarez]

Please try to add more context, not only post a link, since it may go stale in the future.

[Praveen Baskar]

thanks for your inputs piet.t@ and mjuarez@. Updated my answer accordingly. feel free to provide your inputs. thanks!

[Irina Rapoport]

Wonder why it's so slow?

[Angus Grant]

@AbhijitGaikwad I believe I have achieved which you and i wanted with this command for i in $(ls -t $(find . -name '*.jar')); do echo $i && jar tf $i; done