Sorry to be naive about java, but isn't .jar just .zip with a manifest and a different extension? Even if the goal is to make jar "100% pure java", which I don

Sorry to be naive about java, but isn't .jar just .zip with a manifest and a different extension? Even if the goal is to make jar "100% pure java", which I don't recall it being, why wouldn't they transcribe a relatively complete implementation of .zip from the get-go? A relatively complete, solid, performant implementation of what is probably the world's most common compression algorithm seems like exactly the kind of thing that belongs in Java's enormous library system. Maybe typical jar duties wouldn't tax it but it seems like someone somewhere would use it for something big and these kinds of issues would have shaken out long ago.