Needed help in using javax.imagio.plugins.jpeg

Question

I want to manipulate DCT coeff of jpeg image
I want to Manipulate JPEG ImageWriteParam
Any one plz give me some tutorials,examples in using javax.image.plugins.jpeg

Answer 1

If you take a glance at the [API for ResultSet|http://java.sun.com/j2se/1.5.0/docs/api/java/sql/ResultSet.html#next()] you might notice that the rs.next() method returns a boolen value.
It returns true if there IS a next record, otherwise false.
Most people write code something like
if (rs.next()){
  // if only one result is expected
//or
while(rs.next()){
  // if multiple rows are expected.
}