test/java/util/Collections/ReverseOrder.java

rev 6620 : 8001667: Comparator combinators and extension methods
Reviewed-by: mduigou, briangoetz
Contributed-by: henry.jen@oracle.com

*** 21,47 ****
   * questions.
   */
  
  /*
   * @test
!  * @bug 4593209
   * @summary Reverse comparator was subtly broken
   * @author Josh bloch
   */
  
  import java.util.*;
  
  public class ReverseOrder {
      public static void main(String[] args) throws Exception {
          Foo[] a = { new Foo(2), new Foo(3), new Foo(1) };
          List list = Arrays.asList(a);
!         Collections.sort(list, Collections.reverseOrder());
  
          Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) };
          List goldenList = Arrays.asList(golden);
          if (!list.equals(goldenList))
              throw new Exception(list.toString());
      }
  }
  
  class Foo implements Comparable {
      int val;
--- 21,80 ----
   * questions.
   */
  
  /*
   * @test
!  * @bug 4593209 8001667
   * @summary Reverse comparator was subtly broken
   * @author Josh bloch
   */
  
  import java.util.*;
+ import java.io.*;
  
  public class ReverseOrder {
+     static byte[] serialBytes(Object o) {
+         try {
+             ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             ObjectOutputStream oos = new ObjectOutputStream(bos);
+             oos.writeObject(o);
+             oos.flush();
+             oos.close();
+             return bos.toByteArray();
+         } catch (Throwable t) {
+             throw new Error(t);
+         }
+     }
+ 
+     @SuppressWarnings("unchecked")
+     static <T> T serialClone(T o) {
+         try {
+             ObjectInputStream ois = new ObjectInputStream
+                 (new ByteArrayInputStream(serialBytes(o)));
+             T clone = (T) ois.readObject();
+             return clone;
+         } catch (Throwable t) {
+             throw new Error(t);
+         }
+     }
+ 
      public static void main(String[] args) throws Exception {
          Foo[] a = { new Foo(2), new Foo(3), new Foo(1) };
          List list = Arrays.asList(a);
!         Comparator cmp = Collections.reverseOrder();
!         Collections.sort(list, cmp);
  
          Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) };
          List goldenList = Arrays.asList(golden);
          if (!list.equals(goldenList))
              throw new Exception(list.toString());
+ 
+         Comparator clone = serialClone(cmp);
+         List list2 = Arrays.asList(a);
+         Collections.sort(list2, clone);
+         if (!list2.equals(goldenList))
+             throw new Exception(list.toString());
      }
  }
  
  class Foo implements Comparable {
      int val;