How to send a flat file to application server ?

How to send a flat file to application server ?
in
3 types
1.to write in bound inteface
   in bdc > call transation

•   In call transation the data will processed immidetly.
•   In call transation   errors wil not handle
• For errors we have to use bdcmsgcoll .
• This is used for short data.

            >session method

• In session the data should not processed immidietly.when we have to process at that time it will process
• In session the Background jobs are created ,
• The errors will stored in log file.

2.to write lsmw(this for excat or straight forward data , at that time this is using)

3.Stranded program  :cg3z  this is direct file tranfer program.