shaiful Welcome to the Java Ranch, we hope you’ll enjoy visiting as a regular however, your name is not in keeping with our naming policy here at the ranch. Please re-register under an appropriate name as shown in the policy. Thanks again and we hope to see you around the ranch!!
Also, I dont think the JDBC forum is the place to ask about swing - as soon as David see's this I'm sure it'll get moved.
There have been a few of the calculator projects in the beginner forum. You could do a search there. Since this is most likely a class project, I think you would learn more by trying the project and then asking more detailed questions from that.