V1’s advice pertains to Oracle versions of Java (7 and up). Older versions (up to and including 6) were provided by Apple. Those older versions can still be installed and work on current Macs running anything up to and including Yosemite (10.10.2), which is not to say you should (but see below
*). Unfortunately, in Yosemite (and possibly earlier Mac OS X versions) Apple Java versions will not be seen by the online test V1 linked to, nor will you see a Java System Prefs panel servicing it. In addition, Yosemite no longer comes with Apple’s
Java Preferences utility, although it still appears to support copies from previous OS X versions, at least all the way back to Mac OS X 10.5 and the PPC-Mac era.
That said, there is an issue with having different versions of Java installed concurrently. While Apple’s JP allowed that, this is no longer the case with Oracle’s Java (7 and up): you can only keep one version of its Java around (ideally the latest), and
have to uninstall the existing one to accommodate another. I don’t yet know, however, if older Apple Java versions can coexist with Oracle’s.
To return to the issue underlying your query, the inability to run a ping test begs the question whether such a test should be Java-based to begin with, let alone with a Java version that’s not up-to-date. It also makes a difference if the ping is intended to test a LAN or an internet item. Using Java online is always dangerous, with the possible exception of known sites, where one is sure to actually access that site and not an imposter. This is the reason Apple removed Java from its OS installs, and the Java checkbox from Safari’s Security Prefs panel.
In this case the fact that the Java plugin is not enabled may mean that an older and more vulnerable version of Java is installed; if there’s none installed, the latest (Oracle) plugin will do. But it’s much better to a use non-Java based ping utility altogether. For internet purposes, how about the online
Network Tools? Alternatively, use what you already have at hand:
How to Ping on Mac OS.
*) The main reason you might want to keep older Java versions around is for legacy purposes: to enable (locally run) software that hasn’t been updated to run with newer versions of Java. Even so, it’s MUCH better to look for alternatives than to keep on using older Java versions, but sometimes that’s just not possible. And as long as this Java isn’t used online to run web applets, there shouldn’t be any security issues (Apple disables the Java SE 6 web plugin on new J6 installs, but this block can be circumvented by using the latest version of Oracle’s Java web plugin). And anyone still using J6 should make sure to apply Apple’s latest security update (
2014-01) while realizing that
this still is not 100% safe. Fortunately, most users will not need to keep potentially dangerous (older versions of) Java around, and should remove them from their computers if they can’t be sure they can be effectively disabled.