When you download the Java Development Kit (JDK), the associated Java Runtime Environment (JRE) is installed at the same time. JDK 7 Installation Instructions Installation of the 64-bit JDK on Mac Platforms To install a lower version of the JRE, first uninstall the current version. 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 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.
