Question

In general in java, when do you use the following import statements
a) import java.io;
b) import java.*;

Answer 1

Well, if you think about what the wildcard means, you can guess why it is avoided. But here is a little ore technical description on it:

http://www.javaperformancetuning.com/news/qotm031.shtml

Answer 2

You use that "*" so that all are included. For example, import java.*; includes all the java libraries. And where as import java.io; imports only th Input/Output API