OnJava8-Examples/generics/UnboundedWildcards2.java
2015-04-20 15:36:01 -07:00

22 lines
683 B
Java

//: generics/UnboundedWildcards2.java
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<String,Integer>());
assign2(new HashMap<String,Integer>());
assign3(new HashMap<String,Integer>());
}
} ///:~