OnJava8-Examples/generics/UnboundedWildcards2.java
2015-12-15 11:47:04 -08:00

25 lines
814 B
Java

// generics/UnboundedWildcards2.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.*;
public class UnboundedWildcards2 {
static Map map1;
static Map<?,?> map2;
static Map<String,?> map3;
static void assign1(Map map) { map1 = map; }
static void assign2(Map<?,?> map) { map2 = map; }
static void assign3(Map<String,?> map) { map3 = map; }
public static void main(String[] args) {
assign1(new HashMap());
assign2(new HashMap());
// assign3(new HashMap()); // Warning:
// Unchecked conversion. Found: HashMap
// Required: Map<String,?>
assign1(new HashMap<>());
assign2(new HashMap<>());
assign3(new HashMap<>());
}
}