--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/BufferArray.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import java.nio.DoubleBuffer;
+import jdk.nashorn.api.scripting.AbstractJSObject;
+
+/**
+ * Simple class demonstrating pluggable script object
+ * implementation. By implementing jdk.nashorn.api.scripting.JSObject
+ * (or extending AbstractJSObject which implements it), you
+ * can supply a friendly script object. Nashorn will call
+ * 'magic' methods on such a class on 'obj.foo, obj.foo = 33,
+ * obj.bar()' etc. from script.
+ *
+ * In this example, Java nio DoubleBuffer object is wrapped
+ * as a friendly script object that provides indexed acces
+ * to buffer content and also support array-like "length"
+ * readonly property to retrieve buffer's capacity. This class
+ * also demonstrates a function valued property called "buf".
+ * On 'buf' method, we return the underlying nio buffer object
+ * that is being wrapped.
+ */
+public class BufferArray extends AbstractJSObject {
+    // underlying nio buffer
+    private final DoubleBuffer buf;
+
+    /**
+     * Constructor
+     * @param size initial size
+     */
+    public BufferArray(final int size) {
+        buf = DoubleBuffer.allocate(size);
+    }
+
+    /**
+     * Constructur
+     * @param buf {@link DoubleBuffer} to link to
+     */
+    public BufferArray(final DoubleBuffer buf) {
+        this.buf = buf;
+    }
+
+    // called to check if indexed property exists
+    @Override
+    public boolean hasSlot(final int index) {
+        return index > 0 && index < buf.capacity();
+    }
+
+    // get the value from that index
+    @Override
+    public Object getSlot(final int index) {
+       return buf.get(index);
+    }
+
+    // set the value at that index
+    @Override
+    public void setSlot(final int index, final Object value) {
+       buf.put(index, ((Number)value).doubleValue());
+    }
+
+    // do you have a property of that given name?
+    @Override
+    public boolean hasMember(final String name) {
+       return "length".equals(name) || "buf".equals(name);
+    }
+
+    // get the value of that named property
+    @Override
+    public Object getMember(final String name) {
+       switch (name) {
+          case "length":
+              return buf.capacity();
+          case "buf":
+              // return a 'function' value for this property
+              return new AbstractJSObject() {
+                  @Override
+                  public Object call(final Object thiz, final Object... args) {
+                      return BufferArray.this.buf;
+                  }
+
+                  // yes, I'm a function !
+                  @Override
+                  public boolean isFunction() {
+                      return true;
+                  }
+              };
+          default:
+              break;
+       }
+       return null;
+    }
+}