WeakHashMap(Map <? extends K ,? extends V > m) constructor from WeakHashMap has the following syntax.
public WeakHashMap(Map <? extends K ,? extends V> m)
In the following code shows how to use WeakHashMap.WeakHashMap(Map <? extends K ,? extends V > m) constructor.
import java.util.HashMap; import java.util.Map; import java.util.WeakHashMap; /* w w w .ja va 2 s . c o m*/ public class Main { public static void main(String[] args) { Map<String, String> hashMap = new HashMap<String, String> (); hashMap.put("1", "first"); hashMap.put("2", "two"); hashMap.put("3", "from java2s.com"); Map<String, String> weakHashMap = new WeakHashMap<String, String> (hashMap); } }