Generic Programming - Java Concepts - page 1062

ordinary Java types. Each type variable is replaced with its bound, or with Object if
it is not bounded.
The virtual machine works with raw types, not with generic classes.
The raw type of a generic type is obtained by erasing the type variables.
The compiler erases the type variables when it compiles generic classes and methods.
For example, the generic class Pair < T, S > turns into the following raw
class:
public class Pair
{
public Pair( Object firstElement, Object
secondElement)
{
first = firstElement;
second = secondElement;
}
public Object getFirst() { return first; }
public Object getSecond() { return second; }
private Object first;
private Object second;
}
As you can see, the type variables T and S have been replaced by Object . The result
is an ordinary class.
The same process is applied to generic methods. After erasing the type parameter, the
min method of the preceding section turns into an ordinary method:
public static Comparable min( Comparable [] a)
{
Comparable smallest = a[0];
for (int i = 1; i < a.length; i++)
if (a[i].compareTo(smallest) < 0) smallest =
a[i];
return smallest;
}