1 /*
   2  * Copyright (c) 2013, 2016, 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 java.beans;
  27 
  28 import java.lang.ref.SoftReference;
  29 import java.lang.ref.WeakReference;
  30 import java.lang.reflect.Method;
  31 
  32 import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
  33 
  34 final class MethodRef {
  35     private String signature;
  36     private SoftReference<Method> methodRef;
  37     private WeakReference<Class<?>> typeRef;
  38 
  39     void set(Method method) {
  40         if (method == null) {
  41             this.signature = null;
  42             this.methodRef = null;
  43             this.typeRef = null;
  44         }
  45         else {
  46             this.signature = method.toGenericString();
  47             this.methodRef = new SoftReference<>(method);
  48             this.typeRef = new WeakReference<Class<?>>(method.getDeclaringClass());
  49         }
  50     }
  51 
  52     boolean isSet() {
  53         return this.methodRef != null;
  54     }
  55 
  56     Method get() {
  57         if (this.methodRef == null) {
  58             return null;
  59         }
  60         Method method = this.methodRef.get();
  61         if (method == null) {
  62             method = find(this.typeRef.get(), this.signature);
  63             if (method == null) {
  64                 this.signature = null;
  65                 this.methodRef = null;
  66                 this.typeRef = null;
  67                 return null;
  68             }
  69             this.methodRef = new SoftReference<>(method);
  70         }
  71         return isPackageAccessible(method.getDeclaringClass()) ? method : null;
  72     }
  73 
  74     private static Method find(Class<?> type, String signature) {
  75         if (type != null) {
  76             for (Method method : type.getMethods()) {
  77                 if (type.equals(method.getDeclaringClass())) {
  78                     if (method.toGenericString().equals(signature)) {
  79                         return method;
  80                     }
  81                 }
  82             }
  83         }
  84         return null;
  85     }
  86 }