1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 package p;
  25 
  26 import java.lang.invoke.*;
  27 import java.lang.reflect.Field;
  28 import java.util.Arrays;
  29 import java.util.Comparator;
  30 import java.util.List;
  31 import java.util.stream.Collectors;
  32 
  33 import jdk.experimental.value.ValueType;
  34 import p.internal.Point;
  35 
  36 public class Main {
  37     private static List<String> FIELD_NAMES = List.of("x", "y", "z");
  38     private static List<Class<?>> FIELD_TYPES =  List.of(int.class, short.class, short.class);
  39 
  40     public static void main(String... args) throws Exception {
  41         ValueType<?> valueType = ValueType.forClass(Point.class);
  42         Module module = Point.class.getModule();
  43         assertTrue(module.isNamed(), "unexpected " + module.toString());
  44         assertTrue(valueType.boxClass().getModule() == module,
  45                    "unexpected " + valueType.boxClass().getModule());
  46         assertTrue(valueType.valueClass().getModule() == module,
  47             "unexpected " + valueType.valueClass().getModule() );
  48 
  49         Field[] fields = Point.class.getDeclaredFields();
  50         assertTrue(fields.length == FIELD_NAMES.size(), Arrays.toString(fields));
  51 
  52         // validate field names
  53         List<String> names = Arrays.stream(fields)
  54                                    .sorted(Comparator.comparing(Field::getName))
  55                                    .map(Field::getName)
  56                                    .collect(Collectors.toList());
  57         assertTrue(names.equals(FIELD_NAMES), names.toString());
  58 
  59         // validate field types
  60         List<Class<?>> types = Arrays.stream(fields)
  61                                      .sorted(Comparator.comparing(Field::getName))
  62                                      .map(Field::getType)
  63                                      .collect(Collectors.toList());
  64         assertTrue(types.equals(FIELD_TYPES), types.toString());
  65 
  66         // getting MethodHandle
  67         MethodHandles.Lookup lookup =
  68             MethodHandles.privateLookupIn(Point.class, MethodHandles.lookup());
  69         for (Field f : fields) {
  70             MethodHandle mh1 = valueType.findGetter(lookup, f.getName(), f.getType());
  71             MethodHandle mh2 = valueType.findWither(lookup, f.getName(), f.getType());
  72             System.out.println(mh1 + " " + mh2);
  73         }
  74     }
  75 
  76     private static void assertTrue(boolean b, String msg) {
  77         if (!b) {
  78             throw new RuntimeException(msg);
  79         }
  80     }
  81 }