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javajarpackaging

Problem when packaging using jar

I try to use jar command to pack a bunch of java class files and images that are used by them. I have .class files in two folders (packages): a and b, and all the images in folder c. I also have a manifest.mf file in META-INF folder, and inside manifest.mf I specify the main class when launching the jar file. I use the following jar command:

jar cvf MyJar.jar a b c META-INF

But the output MyJar.jar simply doesn't run at all. Did I miss anything? Thanks!

Solution

  • It seems that manifest files need to be handled with a special parameter:

    If you have a pre-existing manifest file that you want the jar tool to use for the new jar archive, you can specify it using the -m option:

     % jar cmf myManifestFile myJarFile *.class

    So, in your case

    % jar cvmf META-INF/manifest.mf MyJar.jar a b c META-INF

    If you do not need the META-INF anymore (for other files in there), I'd drop it to be on the safe side.