I am a fresher.I woundered what adobe has done in livecycle import option.so i want to know wht is the programming language used and how they read graphical fields like line,circle.
I don't really understand the question.
1) If you are asking to programmatically invoke LC you can use SOAP, Rest, Java, or a watched folder.
2) If you're asking what language was used to develop LC I don't know why you would care as it's irrelevant to it's usage.
3) LC converts different document types using different methods, for example a Word doc uses Office or Openoffice
Actually i was asked about the features of LC design engines import options.so,i am not asking about the usage of LC.i have generated a pdf document using LC design engine and i have imported. its working fine.but i have generated a pdf document using Java(iText),when i importing the pdf document that has been generated by java(iText),its not working good.the document which i was generated has graphics(using Java graphics2D).so why i am not able to modify the document as like the document generated by LC design engine?
Programatically, Java is the language used to implement business logic that would plug into LiveCycle. I believe you can use C# for older versions. However, that information is irrelevant to your problem.
That being said, it's typically not advisable to be modifying PDF files generated by different applications (iText, Adobe LiveCycle, etc.). While both documents may render out as "PDF", they will not be created internally in the same manner. I would advise that it may be easy to add PDF files generated by other applications as attachments, they are not going to be easily handled unless you address each specific document in a custom manner.