1 install the ide and run it on java8 , this will work well
2 close the eclipse and add "-vm\n
/bin/javaw.exe" to first line eclipse.ini to let your eclipse run on java7
3 start eclipse and wait some seconds , you will find a dialog showed at lower right corner of your desktop.
4 click the "Got it , please don't show..." and the dialog will close
5 restart the eclipse and you will not get the dialog.