Name: auR10023 Date: 08/04/2000



HashMap.entrySet().addAll(Collection) does not throw UnsupportedOperationException for empty Collection. Following example shows that first call of the addAll() method does not throw UnsupportedOperationException when collection has no elements.

 ---------test.java----------
 import java.util.*;

 class test {
     public static void main(String [] args) {
         Vector vect = new Vector();
         HashMap map = new HashMap();
         Set set = map.entrySet();
         try {
             set.addAll(vect);
             // ^^^^^^^^^^^^ The UnsupportedOperationException should be thrown here

         } catch (UnsupportedOperationException e) {
             System.out.println("UnsupportedOperationException exception was " +
                                "thrown for empty collection");
         }

         vect.addElement("val");
         try {
             set.addAll(vect);
         } catch (UnsupportedOperationException e) {
             System.out.println("UnsupportedOperationException exception was " +
                                "thrown for non empty collection");
         }

     }
 }
 ------output--------

 Second exception was thrown

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