The one exception is that the system will not replace the current JRE with a lower version. Installing the JDK also installs the JRE. You cannot install Java for a single user. Wide basis, for all users, and administrator privileges are Note that installing the JDK on a Mac is performed on a system Any Intel-based Mac running Mac OS X 10.7.3 (Lion) or.See the Mac OS X Platform Install FAQ for general information about installing JDK 7 on Mac OS X. See JDK 7 and JRE 7 Installation Guide for general information about installing JDK 7 and JRE 7.