Keep getting a "java" command-line tool notification on macOS Sierra 10
The problem was in my case that I installed the JRE, which was installed only as Safari Plugin, but not as usable commandline tool. Therefore /usr/libexec/java_home -v * would not find any installed Java. 

The solution is to install the JDK, not the JRE.

Recommending to install Java 6 is not a good idea, this is an outdated version that does not have current security fixes and TLS ciphers.

Oracle should fix this - should not be difficult to make a correct OSX installation.