Using a Vagrant box (chef/centos-7.0) as the build server:

$ yum install rpm-build

... get rpmrebuild rpm from sourceforge

$ rpm -Uvh rpmrebuild-2.11-1.noarch.rpm

... get oracle jdk rpm from oracle

$ rpmrebuild --define "_rpmfilename jdk8.rpm" --change-spec-preamble='sed -e "s/^Name:.*/Name: jdk8/"' --package jdk-8u20-linux-x64.rpm