my file contains several line of sql statement like " Select triangle where area > 10 "
square , polygon and triangle are my classes that extends shape.And i have a set on each of class that contains different sized triangle, square and polygon.So when I read area , I must go to the right class in that case which is triangle and find all area > 10 in triangles set.

yes , you are right but my problem is I don't know anything about reflection so I though that I might solve it by using generic.

I want to read a file which contains name of variable that are in class A,B and C and some other data ,I want to identify the class's variable which I read when tokenizing the file to further implementation.

Thanks

Thanks guys..

I found my error ,first I closed the bracket '}' in the first program which is cause to other program does not know conn object and for printing the result of query I have used system.out which is just OUT .print in JSP