How to decompile a whole Jar file? [closed]

2009: JavaDecompiler can do a good job with a jar: since 0.2.5, All files, in JAR files, are displayed.

See also the question "How do I “decompile” Java class files?".

The JD-Eclipse doesn't seem to have changed since late 2009 though (see Changes).
So its integration with latest Eclipse (3.8, 4.2+) might be problematic.

JD-Core is actively maintained.

Both are the result of the fantastic work of (SO user) Emmanuel Dupuy.

2018: A more modern option, mentioned in the comments by David Kennedy Araujo:

JetBrains/intellij-community/plugins/java-decompiler/engine

Fernflower is the first actually working analytical decompiler for Java and probably for a high-level programming language in general.

java -jar fernflower.jar [-<option>=<value>]* [<source>]+ <destination>java -jar fernflower.jar -hes=0 -hdc=0 c:\Temp\binary\ -e=c:\Java\rt.jar c:\Temp\source\

See also How to decompile to java files intellij idea for a command working with recent IntelliJ IDEA.

First of all, it's worth remembering that all Java archive files (.jar/.war/etc...) are all basically just fancy.zip files, with a few added manifests and metadata.

Second, to tackle this problem I personally use several tools which handle this problem on all levels:

• Jad + Jadclipse while working in IDE for decompiling .class files
• WinRAR, my favorite compression tool natively supports Java archives (again, see first paragraph).
• Beyond Compare, my favorite diff tool, when configured correctly can do on-the-fly comparisons between any archive file, including jars. Well worth a try.

The advantage of all the aforementioned, is that I do not need to hold any other external tool which clutters my work environment. Everything I will ever need from one of those files can be handled inside my IDE or diffed with other files natively.

If you happen to have both a bash shell and jad:

JAR=(your jar file name)unzip -d $JAR.tmp $JARpushd $JAR.tmpfor f in `find . -name '*.class'`; do    jad -d $(dirname $f) -s java -lnc $fdonepopd

I might be a tiny, tiny bit off with that, but it should work more or less as advertised. You should end up with $JAR.tmp containing your decompiled files.