for example i have two times one is the system time its stored as an integer if the time is 15:32:21 its stored as 153221
and the flight time stored as an integer as well
This time that you have, which is stored as an integer, is not compatible with the current (system) time from the System class. So when you say system time, what are you referring to?
now i need to get the difference between this two times
in my program i'm using an if statement if the current system is greater than the flight time
then it should subtract the flight time from the system time and display the difference in the time format
otherwise it should say you missed the flight
If all you want is to check if you missed the flight, then what you described should work. If you actually need to calculate the difference in time, then you will have to develop an algorithm for your format. Or you can take the string version, parse it with the simple data format class to a Date object to find the difference, in milliseconds.
Henry