How you guys deal with some magic number, like the index of data field?
For example, on UI portion, you have to know the index of owner field is 5
so you can set a customer ID when someone book a contractor, like
data = "BS123456";
I fear that your point (2) might have contravened this requirement if you assume in your code that the application should have been started previously with the "server" mode.
By this i mean, If sun says "" means both the server and client must run it means you must (1) start the server,
then (2) start the client in the same execution instance/main() method entry point.