Java Generics

[zonic]

Why and where ? we do need to use java generics?

example
public abstract class refData<I> {
public abstract void printCustome(I query);
}

Please provide an example which helpful for me to get the full picture .

[eRaaaa]

Have you read the generic lesson on the java tutorials page? Lesson: Generics (The Java™ Tutorials > Learning the Java Language)