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.lang.constant.ConstantDescs.BSM_INVOKE;
  33 import static java.lang.constant.ConstantDescs.MHR_CLASSDESC_FACTORY;
  34 import static java.util.Objects.requireNonNull;
  35 
  36 /**
  37  * A <a href="package-summary.html#nominal">nominal descriptor</a> for the class
  38  * constant corresponding to a primitive type (e.g., {@code int.class}).
  39  */
  40 final class PrimitiveClassDescImpl
  41         extends DynamicConstantDesc<Class<?>> implements ClassDesc {
  42 
  43     private final String descriptor;
  44 
  45     /**
  46      * Create a {@linkplain ClassDesc} given a descriptor string for a primitive
  47      * type.
  48      *
  49      * @param descriptor the descriptor string, which must be a one-character
  50      * string corresponding to one of the nine base types as per JVMS 4.3
  51      * @throws IllegalArgumentException if the descriptor string does not
  52      * describe a valid primitive type
  53      * @jvms 4.3 Descriptors
  54      */
  55     PrimitiveClassDescImpl(String descriptor) {
  56         super(ConstantDescs.BSM_PRIMITIVE_CLASS, requireNonNull(descriptor), ConstantDescs.CR_Class);
  57         if (descriptor.length() != 1
  58             || "VIJCSBFDZ".indexOf(descriptor.charAt(0)) < 0)
  59             throw new IllegalArgumentException(String.format("not a valid primitive type descriptor: %s", descriptor));
  60         this.descriptor = descriptor;
  61     }
  62 
  63     @Override
  64     public String descriptorString() {
  65         return descriptor;
  66     }
  67 
  68     @Override
  69     public Class<?> resolveConstantDesc(MethodHandles.Lookup lookup) {
  70         return Wrapper.forBasicType(descriptorString().charAt(0)).primitiveType();
  71     }
  72 
  73     @Override
  74     public Optional<? extends ConstantDesc<ConstantDesc<Class<?>>>> describeConstable() {
  75         return Optional.of(DynamicConstantDesc.of(BSM_INVOKE, MHR_CLASSDESC_FACTORY, descriptor));
  76     }
  77 
  78     @Override
  79     public String toString() {
  80         return String.format("PrimitiveClassDesc[%s]", displayName());
  81     }
  82 }