diff -r a0f39cc47387 -r 46084917fde7 src/java.base/share/classes/java/nio/channels/ReadableByteChannel.java
--- a/src/java.base/share/classes/java/nio/channels/ReadableByteChannel.java	Fri Nov 22 17:20:43 2019 +0100
+++ b/src/java.base/share/classes/java/nio/channels/ReadableByteChannel.java	Fri Nov 22 09:00:16 2019 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2001, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2019, 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
@@ -84,6 +84,9 @@
      * @return  The number of bytes read, possibly zero, or {@code -1} if the
      *          channel has reached end-of-stream
      *
+     * @throws  IllegalArgumentException
+     *          If the buffer is read-only
+     *
      * @throws  NonReadableChannelException
      *          If this channel was not opened for reading
      *