src/share/classes/java/util/Collections.java

rev 7893 : 8023275: Wrapping collections should override default methods
Reviewed-by:

@@ -25,18 +25,18 @@
 
 package java.util;
 import java.io.Serializable;
 import java.io.ObjectOutputStream;
 import java.io.IOException;
-import java.io.InvalidObjectException;
 import java.lang.reflect.Array;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.UnaryOperator;
+import java.util.stream.IntStream;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
 /**
  * This class consists exclusively of static methods that operate on or return

@@ -1146,11 +1146,20 @@
         @SuppressWarnings("unchecked")
         @Override
         public Spliterator<E> spliterator() {
             return (Spliterator<E>)c.spliterator();
         }
-
+        @SuppressWarnings("unchecked")
+        @Override
+        public Stream<E> stream() {
+            return (Stream<E>)c.stream();
+        }
+        @SuppressWarnings("unchecked")
+        @Override
+        public Stream<E> parallelStream() {
+            return (Stream<E>)c.parallelStream();
+        }
     }
 
     /**
      * Returns an unmodifiable view of the specified set.  This method allows
      * modules to provide users with "read-only" access to internal sets.

@@ -2007,12 +2016,12 @@
      * collection.  In order to guarantee serial access, it is critical that
      * <strong>all</strong> access to the backing collection is accomplished
      * through the returned collection.<p>
      *
      * It is imperative that the user manually synchronize on the returned
-     * collection when traversing it via {@link Iterator} or
-     * {@link Spliterator}:
+     * collection when traversing it via {@link Iterator}, {@link Spliterator}
+     * or {@link Stream}:
      * <pre>
      *  Collection c = Collections.synchronizedCollection(myCollection);
      *     ...
      *  synchronized (c) {
      *      Iterator i = c.iterator(); // Must be in the synchronized block

@@ -2118,10 +2127,18 @@
         }
         @Override
         public Spliterator<E> spliterator() {
             return c.spliterator(); // Must be manually synched by user!
         }
+        @Override
+        public Stream<E> stream() {
+            return c.stream(); // Must be manually synched by user!
+        }
+        @Override
+        public Stream<E> parallelStream() {
+            return c.parallelStream(); // Must be manually synched by user!
+        }
         private void writeObject(ObjectOutputStream s) throws IOException {
             synchronized (mutex) {s.defaultWriteObject();}
         }
     }
 

@@ -3170,10 +3187,14 @@
         public boolean removeIf(Predicate<? super E> filter) {
             return c.removeIf(filter);
         }
         @Override
         public Spliterator<E> spliterator() {return c.spliterator();}
+        @Override
+        public Stream<E> stream()           {return c.stream();}
+        @Override
+        public Stream<E> parallelStream()   {return c.parallelStream();}
     }
 
     /**
      * Returns a dynamically typesafe view of the specified queue.
      * Any attempt to insert an element of the wrong type will result in

@@ -5095,10 +5116,26 @@
             if (fromIndex > toIndex)
                 throw new IllegalArgumentException("fromIndex(" + fromIndex +
                                                    ") > toIndex(" + toIndex + ")");
             return new CopiesList<>(toIndex - fromIndex, element);
         }
+
+        // Override default methods in Collection
+        @Override
+        public Stream<E> stream() {
+            return IntStream.range(0, n).mapToObj(i -> element);
+        }
+
+        @Override
+        public Stream<E> parallelStream() {
+            return IntStream.range(0, n).parallel().mapToObj(i -> element);
+        }
+
+        @Override
+        public Spliterator<E> spliterator() {
+            return stream().spliterator();
+        }
     }
 
     /**
      * Returns a comparator that imposes the reverse of the <em>natural
      * ordering</em> on a collection of objects that implement the

@@ -5502,10 +5539,14 @@
             return s.removeIf(filter);
         }
 
         @Override
         public Spliterator<E> spliterator() {return s.spliterator();}
+        @Override
+        public Stream<E> stream()           {return s.stream();}
+        @Override
+        public Stream<E> parallelStream()   {return s.parallelStream();}
 
         private static final long serialVersionUID = 2454657854757543876L;
 
         private void readObject(java.io.ObjectInputStream stream)
             throws IOException, ClassNotFoundException

@@ -5567,12 +5608,16 @@
 
         // Override default methods in Collection
         @Override
         public void forEach(Consumer<? super E> action) {q.forEach(action);}
         @Override
-        public Spliterator<E> spliterator() {return q.spliterator();}
-        @Override
         public boolean removeIf(Predicate<? super E> filter) {
             return q.removeIf(filter);
         }
+        @Override
+        public Spliterator<E> spliterator() {return q.spliterator();}
+        @Override
+        public Stream<E> stream()           {return q.stream();}
+        @Override
+        public Stream<E> parallelStream()   {return q.parallelStream();}
     }
 }