wget --header "Cookie: oraclelicense=accept-securebackup-cookie" [DOWNLOAD-URL]
Example: download JDK 8u66 for Mac OS X
wget --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u66-b17/jdk-8u66-macosx-x64.dmg