Sets Java's web proxy properties, so that tasks and code run in the same JVM can have through-the-firewall access to remote web sites, and remote ftp sites. You can nominate an http and ftp proxy, or a socks server, reset the server settings, or do nothing at all.
<setproxy/> do nothing
<setproxy proxyhost="firewall"/> set the proxy to firewall:80
<setproxy proxyhost="firewall" proxyport="81"/> set the proxy to firewall:81
<setproxy proxyhost=""/> stop using the http proxy; don't change the socks settings
<setproxy socksproxyhost="socksy"/> use socks via socksy:1080
<setproxy socksproxyhost=""/> stop using the socks server.
You can set a username and password for http with the proxyHost and proxyPassword attributes. On Java1.4 and above these can also be used against SOCKS5 servers.