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Obtaining Manifest from Jar

Doug Melzer
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Joined: Mar 23, 2000
Posts: 51
I'd like to obtain a version number from a .jar file's manifest, but I'd like to do so without having to know the file location of the .jar file.
Is it possible, given a class that was loaded from the .jar file, to obtain a handle to that .jar file's manifest?
Thomas Smets
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Joined: Dec 11, 2001
Posts: 111
I believe you will have to work out the jars to find from which file it comes from !
This means that you will have to find all the JAR's in you classpath & find in them where you class source is located ! From there you could search for the MANIFEST file in the current jar !
This could be handy !
Sun's tutorial on how to read Jar from Java !


Thomas Smets
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Steve Deadsea
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Joined: Dec 03, 2001
Posts: 125
There may well be a way to do it without knowing the name of the jar file. It works for other files in the jar file (but note I haven't tried it with anything in the META-INF directory)
The basic idea is that everything that is in the jar file is in the classpath, and you get a InputStream to a system resource from the classloader. Here is how it might work.
Doug Melzer
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Joined: Mar 23, 2000
Posts: 51
I've tried a couple of these ideas, but the problem that I encounter is that if there are multiple .jar files on the classpath that I can't ensure I'm reading the desired manifest file.
Thanks for the suggestions!
 
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