How can I eliminate this repeated Java Runtime Environment (JRE) pop-up window? This window has been popping up repeatedly:

I was sure that I already had the latest version of Java installed, but to verify I went here: https://www.java.com/en/download/installed.jsp

And sure enough I have the latest JRE.


Then I went and followed the directions here to find the JRE via my command line:
https://www.java.com/en/download/help/version_manual.xml#cmdline
which says to enter: 


  $ /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java -version


and the terminal output was:


  java version "1.8.0_25"
  Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
  Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)`


Can anyone help me identify what I'm doing wrong here?  I definitely have Java.
I installed the Java Developer Kit and that fixed the problem. I'm not sure why that was needed.