1 /*
   2  * Copyright (c) 2018, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package java.lang.constant;
  26 
  27 import java.lang.invoke.MethodHandles;
  28 import java.util.Optional;
  29 
  30 import sun.invoke.util.Wrapper;
  31 
  32 import static java.util.Objects.requireNonNull;
  33 
  34 /**
  35  * A <a href="package-summary.html#nominal">nominal descriptor</a> for the class
  36  * constant corresponding to a primitive type (e.g., {@code int.class}).
  37  */
  38 final class PrimitiveClassDescImpl
  39         extends DynamicConstantDesc<Class<?>> implements ClassDesc {
  40 
  41     private final String descriptor;
  42 
  43     /**
  44      * Creates a {@linkplain ClassDesc} given a descriptor string for a primitive
  45      * type.
  46      *
  47      * @param descriptor the descriptor string, which must be a one-character
  48      * string corresponding to one of the nine base types
  49      * @throws IllegalArgumentException if the descriptor string does not
  50      * describe a valid primitive type
  51      * @jvms 4.3 Descriptors
  52      */
  53     PrimitiveClassDescImpl(String descriptor) {
  54         super(ConstantDescs.BSM_PRIMITIVE_CLASS, requireNonNull(descriptor), ConstantDescs.CD_Class);
  55         if (descriptor.length() != 1
  56             || "VIJCSBFDZ".indexOf(descriptor.charAt(0)) < 0)
  57             throw new IllegalArgumentException(String.format("not a valid primitive type descriptor: %s", descriptor));
  58         this.descriptor = descriptor;
  59     }
  60 
  61     @Override
  62     public String descriptorString() {
  63         return descriptor;
  64     }
  65 
  66     @Override
  67     public Class<?> resolveConstantDesc(MethodHandles.Lookup lookup) {
  68         return Wrapper.forBasicType(descriptorString().charAt(0)).primitiveType();
  69     }
  70 
  71     @Override
  72     public String toString() {
  73         return String.format("PrimitiveClassDesc[%s]", displayName());
  74     }
  75 
  76     @Override
  77     public Optional<? extends ConstantDesc> describeConstable() {
  78         return Optional.empty();
  79     }
  80 }