OnJava8-Examples/generics/LostInformation.java
2015-12-15 11:47:04 -08:00

34 lines
964 B
Java

// generics/LostInformation.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
import java.util.*;
class Frob {}
class Fnorkle {}
class Quark<Q> {}
class Particle<POSITION,MOMENTUM> {}
public class LostInformation {
public static void main(String[] args) {
List<Frob> list = new ArrayList<>();
Map<Frob,Fnorkle> map = new HashMap<>();
Quark<Fnorkle> quark = new Quark<>();
Particle<Long,Double> p = new Particle<>();
System.out.println(Arrays.toString(
list.getClass().getTypeParameters()));
System.out.println(Arrays.toString(
map.getClass().getTypeParameters()));
System.out.println(Arrays.toString(
quark.getClass().getTypeParameters()));
System.out.println(Arrays.toString(
p.getClass().getTypeParameters()));
}
}
/* Output:
[E]
[K, V]
[Q]
[POSITION, MOMENTUM]
*/