For Linux and MacOS is recomended to use the open-jdk-jre 1.8 or 1.7 included in your system. If they are not available on your system and you can not install them you can download from here.
For Linux is recomended to use the open-jdk-jre 1.7 or 1.6 included in your system. If they are not available on your system and you can not install them you can download from here.