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.MethodHandle;
  28 import java.lang.invoke.MethodHandles;
  29 import java.lang.invoke.MethodType;
  30 
  31 import static java.lang.constant.ConstantDescs.BSM_INVOKE;
  32 import static java.lang.constant.ConstantDescs.CD_MethodHandle;
  33 import static java.util.Objects.requireNonNull;
  34 
  35 /**
  36  * A <a href="package-summary.html#nominal">nominal descriptor</a> for a
  37  * {@link MethodHandle} constant that performs a {@link MethodHandle#asType(MethodType)}
  38  * adaptation on another {@link MethodHandle}.
  39  */
  40 final class AsTypeMethodHandleDesc extends DynamicConstantDesc<MethodHandle>
  41         implements MethodHandleDesc {
  42 
  43     private final MethodHandleDesc underlying;
  44     private final MethodTypeDesc type;
  45 
  46     AsTypeMethodHandleDesc(MethodHandleDesc underlying, MethodTypeDesc type) {
  47         super(BSM_INVOKE, ConstantDescs.DEFAULT_NAME, CD_MethodHandle,
  48               ConstantDescs.MHD_METHODHANDLE_ASTYPE, underlying, type);
  49         this.underlying = requireNonNull(underlying);
  50         this.type = requireNonNull(type);
  51     }
  52 
  53     @Override
  54     public MethodTypeDesc invocationType() {
  55         return type;
  56     }
  57 
  58     @Override
  59     public MethodHandle resolveConstantDesc(MethodHandles.Lookup lookup)
  60             throws ReflectiveOperationException {
  61         MethodHandle handle = (MethodHandle) underlying.resolveConstantDesc(lookup);
  62         MethodType methodType = (MethodType) type.resolveConstantDesc(lookup);
  63         return handle.asType(methodType);
  64     }
  65 
  66     @Override
  67     public String toString() {
  68         return  String.format("%s.asType%s", underlying.toString(), type.displayDescriptor());
  69     }
  70 }