1 /*
   2  * Copyright (c) 2003, 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 
  26 package sun.reflect.generics.repository;
  27 
  28 
  29 import java.lang.reflect.Type;
  30 import sun.reflect.generics.factory.GenericsFactory;
  31 import sun.reflect.generics.visitor.Reifier;
  32 
  33 
  34 
  35 /**
  36  * This class represents the generic type information for a method.
  37  * The code is not dependent on a particular reflective implementation.
  38  * It is designed to be used unchanged by at least core reflection and JDI.
  39  */
  40 public class MethodRepository extends ConstructorRepository {
  41 
  42     /** The generic return type info.  Lazily initialized. */
  43     private volatile Type returnType;
  44 
  45  // private, to enforce use of static factory
  46     private MethodRepository(String rawSig, GenericsFactory f) {
  47       super(rawSig, f);
  48     }
  49 
  50     /**
  51      * Static factory method.
  52      * @param rawSig - the generic signature of the reflective object
  53      * that this repository is servicing
  54      * @param f - a factory that will provide instances of reflective
  55      * objects when this repository converts its AST
  56      * @return a <tt>MethodRepository</tt> that manages the generic type
  57      * information represented in the signature <tt>rawSig</tt>
  58      */
  59     public static MethodRepository make(String rawSig, GenericsFactory f) {
  60         return new MethodRepository(rawSig, f);
  61     }
  62 
  63     public Type getReturnType() {
  64         Type value = returnType;
  65         if (value == null) {
  66             value = computeReturnType();
  67             returnType = value;
  68         }
  69         return value;
  70     }
  71 
  72     private Type computeReturnType() {
  73         Reifier r = getReifier(); // obtain visitor
  74         // Extract return type subtree from AST and reify
  75         getTree().getReturnType().accept(r);
  76         // extract result from visitor and cache it
  77         return r.getResult();
  78     }
  79 
  80 }