Shell Programming and Scripting

Hey all,

My boss tasked me with the job to write a script which would invoke various java programs, the thing is I don't know much about shell scripting so would you experts help me out?

Here is the requirement
- 2 applications written in java: App_A and App_B
- App_A will accept a set of parameters and different action will be
taken depending on the paramters
i.e) ./java App_A Apple and ./java App_A Orange => different results
- App_A can be ran simultaneously with different parameters
i.e) ./java App_A Apple and ./java App_A Orange => run at same time
- App_B must be executed after all instances of App_A are finished

App_A required an input file which would be ftp to our server, so App_A is given a timeframe of one hour to check if the file exists before continue to invoke the program. If within the given timeframe, no file arrived then that instance of App_A would not be invoked.

What I need to do is to write a shell script which would invoke 3 instances of App_A, at least one instance of App_A need to be invoked in order for App_B to be called.

So here is the conclusion
1) all 3 instances of App_A are invoked (files found), so App_B is then called
2) all 3 instances of App_A are not invoked (waited for an hour and still no file found), so App_B won't be invoked instead an error is writen to log file
3) at least 1 instances of App_A is called, App_B is then invoked also an error message is logged.

I hope I explain myself clearly and please all you experts shine some light on me. Thanks! Sample codes would be GREATLY appreciated!!!!