src/java.base/share/classes/java/util/OptionalInt.java

rev 17011 : 8167981: Optional: add notes explaining intended use
Reviewed-by: XXX

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -43,10 +43,17 @@
  * <p>This is a <a href="../lang/doc-files/ValueBased.html">value-based</a>
  * class; use of identity-sensitive operations (including reference equality
  * ({@code ==}), identity hash code, or synchronization) on instances of
  * {@code OptionalInt} may have unpredictable results and should be avoided.
  *
+ * @apiNote
+ * {@code OptionalInt} is primarily intended for use as a method return type where
+ * there is a clear need to represent "no result," and where using {@code null}
+ * is likely to cause errors. A variable whose type is {@code OptionalInt} should
+ * never itself be {@code null}; it should always point to an {@code OptionalInt}
+ * instance.
+ *
  * @since 1.8
  */
 public final class OptionalInt {
     /**
      * Common instance for {@code empty()}.

@@ -108,10 +115,16 @@
 
     /**
      * If a value is present, returns the value, otherwise throws
      * {@code NoSuchElementException}.
      *
+     * @apiNote
+     * The methods {@link #orElse(int) orElse()} and
+     * {@link #orElseGet(java.util.function.IntSupplier) orElseGet()}
+     * are generally preferable to this method, as they return a substitute
+     * value if the value is absent, instead of throwing an exception.
+     *
      * @return the value described by this {@code OptionalInt}
      * @throws NoSuchElementException if no value is present
      * @see OptionalInt#isPresent()
      */
     public int getAsInt() {