For Java 7, you will need an Intel-based Mac running Mac OS X version 10.7.3 (Lion) and above. Installing Java on a Mac is performed on a system wide basis, for all users, and administrator privileges are required. Java 7 can not be installed on a per-user basis.
Browser requirements: A 64-bit browser (Safari or Firefox, for example) is required to run Java 7 on Mac OS X. 32-bit browsers such as Chrome do not support Java 7 on the Mac platform.
Size : 50.3 MB