JAR files and the
Java compiled classes in them are binary data, not text data. XML isn't really suited for transmission of binary data - the only truly safe way to pack a JAR or other binary file into XML is to MIME-encode it into text. Which makes it bigger. And you'd still have to make the whole thing, XML tags and all be 160 characters or less to be able to fit it in an SMS message packet.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.