1/* 2 * Copyright (c) 2010, 2013, 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/* 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file, and Oracle licenses the original version of this file under the BSD 31 * license: 32 */ 33/* 34 Copyright 2009-2013 Attila Szegedi 35 36 Licensed under both the Apache License, Version 2.0 (the "Apache License") 37 and the BSD License (the "BSD License"), with licensee being free to 38 choose either of the two at their discretion. 39 40 You may not use this file except in compliance with either the Apache 41 License or the BSD License. 42 43 If you choose to use this file in compliance with the Apache License, the 44 following notice applies to you: 45 46 You may obtain a copy of the Apache License at 47 48 http://www.apache.org/licenses/LICENSE-2.0 49 50 Unless required by applicable law or agreed to in writing, software 51 distributed under the License is distributed on an "AS IS" BASIS, 52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 53 implied. See the License for the specific language governing 54 permissions and limitations under the License. 55 56 If you choose to use this file in compliance with the BSD License, the 57 following notice applies to you: 58 59 Redistribution and use in source and binary forms, with or without 60 modification, are permitted provided that the following conditions are 61 met: 62 * Redistributions of source code must retain the above copyright 63 notice, this list of conditions and the following disclaimer. 64 * Redistributions in binary form must reproduce the above copyright 65 notice, this list of conditions and the following disclaimer in the 66 documentation and/or other materials provided with the distribution. 67 * Neither the name of the copyright holder nor the names of 68 contributors may be used to endorse or promote products derived from 69 this software without specific prior written permission. 70 71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER 75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 82*/ 83 84package jdk.dynalink.beans; 85 86import java.lang.invoke.MethodHandle; 87import java.lang.invoke.MethodType; 88import java.security.AccessControlContext; 89import java.security.AccessController; 90import java.security.PrivilegedAction; 91import java.util.Arrays; 92import java.util.LinkedList; 93import java.util.List; 94import jdk.dynalink.internal.AccessControlContextFactory; 95import jdk.dynalink.internal.InternalTypeUtilities; 96import jdk.dynalink.linker.LinkerServices; 97import jdk.dynalink.linker.support.TypeUtilities; 98 99/** 100 * Represents a sequence of {@link Class} objects, useful for representing method signatures. Provides value 101 * semantics for using them as map keys, as well as specificity calculations and applicability checks as per 102 * JLS. 103 */ 104final class ClassString { 105 private static final AccessControlContext GET_CLASS_LOADER_CONTEXT = 106 AccessControlContextFactory.createAccessControlContext("getClassLoader"); 107 108 /** 109 * An anonymous inner class used solely to represent the "type" of null values for method applicability checking. 110 */ 111 static final Class<?> NULL_CLASS = (new Object() { /* Intentionally empty */ }).getClass(); 112 113 private final Class<?>[] classes; 114 private int hashCode; 115 116 ClassString(final Class<?>[] classes) { 117 this.classes = classes; 118 } 119 120 ClassString(final MethodType type) { 121 this(type.parameterArray()); 122 } 123 124 @Override 125 public boolean equals(final Object other) { 126 if(!(other instanceof ClassString)) { 127 return false; 128 } 129 final Class<?>[] otherClasses = ((ClassString)other).classes; 130 if(otherClasses.length != classes.length) { 131 return false; 132 } 133 for(int i = 0; i < otherClasses.length; ++i) { 134 if(otherClasses[i] != classes[i]) { 135 return false; 136 } 137 } 138 return true; 139 } 140 141 @Override 142 public int hashCode() { 143 if(hashCode == 0) { 144 int h = 0; 145 for(int i = 0; i < classes.length; ++i) { 146 h ^= classes[i].hashCode(); 147 } 148 hashCode = h; 149 } 150 return hashCode; 151 } 152 153 @Override 154 public String toString() { 155 return "ClassString[" + Arrays.toString(classes) + "]"; 156 } 157 158 boolean isVisibleFrom(final ClassLoader classLoader) { 159 return AccessController.doPrivileged(new PrivilegedAction<Boolean>() { 160 @Override 161 public Boolean run() { 162 for(final Class<?> clazz: classes) { 163 if(!InternalTypeUtilities.canReferenceDirectly(classLoader, clazz.getClassLoader())) { 164 return false; 165 } 166 } 167 return true; 168 } 169 }, GET_CLASS_LOADER_CONTEXT); 170 } 171 172 List<MethodHandle> getMaximallySpecifics(final List<MethodHandle> methods, final LinkerServices linkerServices, final boolean varArg) { 173 return MaximallySpecific.getMaximallySpecificMethodHandles(getApplicables(methods, linkerServices, varArg), 174 varArg, classes, linkerServices); 175 } 176 177 /** 178 * Returns all methods that are applicable to actual parameter classes represented by this ClassString object. 179 */ 180 LinkedList<MethodHandle> getApplicables(final List<MethodHandle> methods, final LinkerServices linkerServices, final boolean varArg) { 181 final LinkedList<MethodHandle> list = new LinkedList<>(); 182 for(final MethodHandle member: methods) { 183 if(isApplicable(member, linkerServices, varArg)) { 184 list.add(member); 185 } 186 } 187 return list; 188 } 189 190 /** 191 * Returns true if the supplied method is applicable to actual parameter classes represented by this ClassString 192 * object. 193 * 194 */ 195 private boolean isApplicable(final MethodHandle method, final LinkerServices linkerServices, final boolean varArg) { 196 final Class<?>[] formalTypes = method.type().parameterArray(); 197 final int cl = classes.length; 198 final int fl = formalTypes.length - (varArg ? 1 : 0); 199 if(varArg) { 200 if(cl < fl) { 201 return false; 202 } 203 } else { 204 if(cl != fl) { 205 return false; 206 } 207 } 208 // Starting from 1 as we ignore the receiver type 209 for(int i = 1; i < fl; ++i) { 210 if(!canConvert(linkerServices, classes[i], formalTypes[i])) { 211 return false; 212 } 213 } 214 if(varArg) { 215 final Class<?> varArgType = formalTypes[fl].getComponentType(); 216 for(int i = fl; i < cl; ++i) { 217 if(!canConvert(linkerServices, classes[i], varArgType)) { 218 return false; 219 } 220 } 221 } 222 return true; 223 } 224 225 private static boolean canConvert(final LinkerServices ls, final Class<?> from, final Class<?> to) { 226 if(from == NULL_CLASS) { 227 return !to.isPrimitive(); 228 } 229 return ls == null ? TypeUtilities.isMethodInvocationConvertible(from, to) : ls.canConvert(from, to); 230 } 231} 232