i tested the above JDK applet values against my new applet. http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2204.0
the values are not the same.
could i check if your y value in thew above JDK applet is indeed 7.924E6 m
i suspect it is the same as counting from center of earth as 6.38E+7.924E6 = 1.43E07
which means if my understanding is valid, both applet did not give the same answer.