samples/BufferArray.java

Fri, 05 Jun 2015 12:38:53 +0200

author
mhaupt
date
Fri, 05 Jun 2015 12:38:53 +0200
changeset 1398
2f1b9f4daec1
parent 1028
d79265f2fa92
permissions
-rw-r--r--

8080087: Nashorn $ENV.PWD is originally undefined
Summary: On Windows, the PWD environment variable does not exist and cannot be imported in scripting mode, so it is set explicitly.
Reviewed-by: lagergren, sundar

     1 /*
     2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
     3  *
     4  * Redistribution and use in source and binary forms, with or without
     5  * modification, are permitted provided that the following conditions
     6  * are met:
     7  *
     8  *   - Redistributions of source code must retain the above copyright
     9  *     notice, this list of conditions and the following disclaimer.
    10  *
    11  *   - Redistributions in binary form must reproduce the above copyright
    12  *     notice, this list of conditions and the following disclaimer in the
    13  *     documentation and/or other materials provided with the distribution.
    14  *
    15  *   - Neither the name of Oracle nor the names of its
    16  *     contributors may be used to endorse or promote products derived
    17  *     from this software without specific prior written permission.
    18  *
    19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
    20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
    23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    30  */
    32 import java.nio.DoubleBuffer;
    33 import jdk.nashorn.api.scripting.AbstractJSObject;
    35 /**
    36  * Simple class demonstrating pluggable script object
    37  * implementation. By implementing jdk.nashorn.api.scripting.JSObject
    38  * (or extending AbstractJSObject which implements it), you
    39  * can supply a friendly script object. Nashorn will call
    40  * 'magic' methods on such a class on 'obj.foo, obj.foo = 33,
    41  * obj.bar()' etc. from script.
    42  *
    43  * In this example, Java nio DoubleBuffer object is wrapped
    44  * as a friendly script object that provides indexed acces
    45  * to buffer content and also support array-like "length"
    46  * readonly property to retrieve buffer's capacity. This class
    47  * also demonstrates a function valued property called "buf".
    48  * On 'buf' method, we return the underlying nio buffer object
    49  * that is being wrapped.
    50  */
    51 public class BufferArray extends AbstractJSObject {
    52     // underlying nio buffer
    53     private final DoubleBuffer buf;
    55     /**
    56      * Constructor
    57      * @param size initial size
    58      */
    59     public BufferArray(final int size) {
    60         buf = DoubleBuffer.allocate(size);
    61     }
    63     /**
    64      * Constructur
    65      * @param buf {@link DoubleBuffer} to link to
    66      */
    67     public BufferArray(final DoubleBuffer buf) {
    68         this.buf = buf;
    69     }
    71     // called to check if indexed property exists
    72     @Override
    73     public boolean hasSlot(final int index) {
    74         return index > 0 && index < buf.capacity();
    75     }
    77     // get the value from that index
    78     @Override
    79     public Object getSlot(final int index) {
    80        return buf.get(index);
    81     }
    83     // set the value at that index
    84     @Override
    85     public void setSlot(final int index, final Object value) {
    86        buf.put(index, ((Number)value).doubleValue());
    87     }
    89     // do you have a property of that given name?
    90     @Override
    91     public boolean hasMember(final String name) {
    92        return "length".equals(name) || "buf".equals(name);
    93     }
    95     // get the value of that named property
    96     @Override
    97     public Object getMember(final String name) {
    98        switch (name) {
    99           case "length":
   100               return buf.capacity();
   101           case "buf":
   102               // return a 'function' value for this property
   103               return new AbstractJSObject() {
   104                   @Override
   105                   public Object call(final Object thiz, final Object... args) {
   106                       return BufferArray.this.buf;
   107                   }
   109                   // yes, I'm a function !
   110                   @Override
   111                   public boolean isFunction() {
   112                       return true;
   113                   }
   114               };
   115           default:
   116               break;
   117        }
   118        return null;
   119     }
   120 }

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