1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
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   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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  23 
  24 /**
  25  * @test
  26  * @bug 8072726
  27  * @summary Tests for Enumeration-to-Iterator conversion.
  28  * @run testng EnumerationAsIterator
  29  */
  30 
  31 import java.util.*;
  32 
  33 import org.testng.annotations.Test;
  34 import static org.testng.Assert.*;
  35 
  36 @Test
  37 public class EnumerationAsIterator {
  38     public void emptyHasNext() {
  39         Iterator<Object> it = Collections.emptyEnumeration().asIterator();
  40         assertFalse(it.hasNext());
  41     }
  42 
  43     @Test(expectedExceptions = {NoSuchElementException.class})
  44     public void emptyNextThrows() {
  45         Iterator<Object> it = Collections.emptyEnumeration().asIterator();
  46         Object o = it.next();
  47     }
  48 
  49     private List<String> copy(List<String> input) {
  50         List<String> output = new ArrayList<>();
  51         Collections.enumeration(input)
  52                    .asIterator()
  53                    .forEachRemaining(output::add);
  54         return output;
  55     }
  56 
  57     public void copyZero() {
  58         assertEquals(copy(Collections.emptyList()), Collections.emptyList());
  59     }
  60 
  61     public void copyOne() {
  62         assertEquals(copy(Collections.singletonList("a")),
  63                           Collections.singletonList("a"));
  64     }
  65 
  66     public void copyMany() {
  67         List<String> input = Arrays.asList("a", "b", "c");
  68         assertEquals(copy(input), input);
  69     }
  70 
  71     @Test(expectedExceptions = {UnsupportedOperationException.class})
  72     public void removeThrowsInitially() {
  73         Collections.enumeration(Arrays.asList("a", "b", "c"))
  74                    .asIterator()
  75                    .remove();
  76     }
  77 
  78     @Test(expectedExceptions = {UnsupportedOperationException.class})
  79     public void removeThrowsLater() {
  80         Iterator<String> iter =
  81             Collections.enumeration(Arrays.asList("a", "b", "c")).asIterator();
  82         iter.next();
  83         iter.remove();
  84     }
  85 
  86 
  87     public void repeatedCalls() {
  88         Iterator<String> iter = new Vector<>(Arrays.asList("a", "b", "c"))
  89             .elements().asIterator();
  90         assertTrue(iter.hasNext());
  91         assertTrue(iter.hasNext());
  92         assertEquals(iter.next(), "a");
  93         assertEquals(iter.next(), "b");
  94         assertEquals(iter.next(), "c");
  95         assertFalse(iter.hasNext());
  96         assertFalse(iter.hasNext());
  97     }
  98 }