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How to view jar files

 
Geoff Garcia
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Aright, I'm pretty much a java newbie.
I understand the basics of the language but have never done real work in it.
Currently I find myself on a project where I'm going to have to do some java development.
I'm at a stage now where I'd like to know whats in all of the jar files utilized by a 3rd party software company that I am interfacing a portal gadget into.
there are a ton of jar files, I've isolated the one I want to view the contents of, but how do I open the darn thing? I've tried wordpad which obviously doesn't work.
Is there some commands I need to run to seperate the .jar file and then be able to view the contents?
Thanks for any help on this simple/novice problem.
Geoff
 
Lasse Koskela
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The JDK contains a utility called "jar". You can create, update, extract, and view .jar files using the "jar" utility.
Here are some useful commands:

Hope I didn't post too many typos
 
damien malone
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you can open up, add and remove files from jar files by using winzip if you want, might be of some help to you
 
Ashik Uzzaman
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I strongly recommend WinRar which is very useful for exploring several kinds of compressed files including ZIP, WAR, TAR etc. I am sure you'ld delighted to get it.
 
Lasse Koskela
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Geoff, if you decide to use WinZip/WinRAR/whatever tools for handling your .jar/.war/.ear files, do remember that a valid .jar file must contain the META-INF/MANIFEST.MF file, which is added by default by the jar utility. With WinZip and others, you must create and add the manifest file yourself (it's not difficult, though).
 
Arvind Varma
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The commands lasse gave are right..but u can add option 'v' to get a verbose version ..

// Gives the table of contents in verbose fashion
jar -tvf
similarly,
//Extracts the files by displaying the information of every file that is being extracted.
jar -xvf
 
Geoff Garcia
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well thanks for the help! I just used the simple winzip tool and got a peek at all the class files in the jars...
I dont know what I was thinking though, looking at .class files is useless to me! I'm trying to figure out why a .jsp call I'm making is failing and thought that by looking at the code of the method I might get a better handle on things.
Any suggestions?
Is there a way to view a .java file from a .class file?
 
Vinod John
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Originally posted by Geoff Garcia:

Is there a way to view a .java file from a .class file?

You can actually unjar/unzip the jar file and use a decompiler like JAD to decompile the class file.
http://www.geocities.com/zz_xu/jad.html
 
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