When does Java's JVM unzip jar files?

Posted by TwentyMiles on Stack Overflow See other posts from Stack Overflow or by TwentyMiles
Published on 2010-05-20T16:05:35Z Indexed on 2010/05/20 16:50 UTC
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jvm

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Java's jar file format builds off of the zip file format, and supports compression of the class files inside it. When and how does the JVM decide which class files to uncompress and pull out of the jars on its classpath? Is the process dynamic and done at runtime as classes are needed, or are they all uncompressed up front before the program actually runs?

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