StaticClassLinker.java revision 1805:7caf1f762f1d 
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.MethodHandles;
88import java.lang.invoke.MethodType;
89import java.lang.reflect.Array;
90import java.util.Arrays;
91import java.util.Set;
92import jdk.dynalink.CallSiteDescriptor;
93import jdk.dynalink.NamedOperation;
94import jdk.dynalink.StandardNamespace;
95import jdk.dynalink.StandardOperation;
96import jdk.dynalink.beans.GuardedInvocationComponent.ValidationType;
97import jdk.dynalink.linker.GuardedInvocation;
98import jdk.dynalink.linker.LinkRequest;
99import jdk.dynalink.linker.LinkerServices;
100import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
101import jdk.dynalink.linker.support.Lookup;
102
103/**
104 * Provides a linker for the {@link StaticClass} objects.
105 */
106class StaticClassLinker implements TypeBasedGuardingDynamicLinker {
107    private static final ClassValue<SingleClassStaticsLinker> linkers = new ClassValue<SingleClassStaticsLinker>() {
108        @Override
109        protected SingleClassStaticsLinker computeValue(final Class<?> clazz) {
110            return new SingleClassStaticsLinker(clazz);
111        }
112    };
113
114    private static class SingleClassStaticsLinker extends AbstractJavaLinker {
115        private final DynamicMethod constructor;
116
117        SingleClassStaticsLinker(final Class<?> clazz) {
118            super(clazz, IS_CLASS.bindTo(clazz));
119            // Map "staticClassObject.class" to StaticClass.getRepresentedClass(). Some adventurous soul could subclass
120            // StaticClass, so we use INSTANCE_OF validation instead of EXACT_CLASS.
121            setPropertyGetter("class", GET_CLASS, ValidationType.INSTANCE_OF);
122            constructor = createConstructorMethod(clazz);
123        }
124
125        /**
126         * Creates a dynamic method containing all overloads of a class' public constructor
127         * @param clazz the target class
128         * @return a dynamic method containing all overloads of a class' public constructor. If the class has no public
129         * constructors, returns null.
130         */
131        private static DynamicMethod createConstructorMethod(final Class<?> clazz) {
132            if(clazz.isArray()) {
133                final MethodHandle boundArrayCtor = ARRAY_CTOR.bindTo(clazz.getComponentType());
134                return new SimpleDynamicMethod(StaticClassIntrospector.editConstructorMethodHandle(
135                        boundArrayCtor.asType(boundArrayCtor.type().changeReturnType(clazz))), clazz, "<init>");
136            }
137            if(CheckRestrictedPackage.isRestrictedClass(clazz)) {
138                return null;
139            }
140            return createDynamicMethod(Arrays.asList(clazz.getConstructors()), clazz, "<init>");
141        }
142
143        @Override
144        FacetIntrospector createFacetIntrospector() {
145            return new StaticClassIntrospector(clazz);
146        }
147
148        @Override
149        public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices)
150                throws Exception {
151            final GuardedInvocation gi = super.getGuardedInvocation(request, linkerServices);
152            if(gi != null) {
153                return gi;
154            }
155            final CallSiteDescriptor desc = request.getCallSiteDescriptor();
156            if(NamedOperation.getBaseOperation(desc.getOperation()) == StandardOperation.NEW && constructor != null) {
157                final MethodHandle ctorInvocation = constructor.getInvocation(desc, linkerServices);
158                if(ctorInvocation != null) {
159                    return new GuardedInvocation(ctorInvocation, getClassGuard(desc.getMethodType()));
160                }
161            }
162            return null;
163        }
164
165        @Override
166        protected GuardedInvocationComponent getGuardedInvocationComponent(final ComponentLinkRequest req) throws Exception {
167            final GuardedInvocationComponent superGic = super.getGuardedInvocationComponent(req);
168            if (superGic != null) {
169                return superGic;
170            }
171            if (!req.namespaces.isEmpty()
172                && req.namespaces.get(0) == StandardNamespace.ELEMENT
173                && (req.baseOperation == StandardOperation.GET || req.baseOperation == StandardOperation.SET))
174            {
175                // StaticClass doesn't behave as a collection
176                return getNextComponent(req.popNamespace());
177            }
178            return null;
179        }
180
181        @Override
182        SingleDynamicMethod getConstructorMethod(final String signature) {
183            return constructor != null? constructor.getMethodForExactParamTypes(signature) : null;
184        }
185    }
186
187    static Object getConstructorMethod(final Class<?> clazz, final String signature) {
188        return linkers.get(clazz).getConstructorMethod(signature);
189    }
190
191    static Set<String> getReadableStaticPropertyNames(final Class<?> clazz) {
192        return linkers.get(clazz).getReadablePropertyNames();
193    }
194
195    static Set<String> getWritableStaticPropertyNames(final Class<?> clazz) {
196        return linkers.get(clazz).getWritablePropertyNames();
197    }
198
199    static Set<String> getStaticMethodNames(final Class<?> clazz) {
200        return linkers.get(clazz).getMethodNames();
201    }
202
203    @Override
204    public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
205        final Object receiver = request.getReceiver();
206        if(receiver instanceof StaticClass) {
207            return linkers.get(((StaticClass)receiver).getRepresentedClass()).getGuardedInvocation(request,
208                    linkerServices);
209        }
210        return null;
211    }
212
213    @Override
214    public boolean canLinkType(final Class<?> type) {
215        return type == StaticClass.class;
216    }
217
218    /*private*/ static final MethodHandle GET_CLASS;
219    /*private*/ static final MethodHandle IS_CLASS;
220    /*private*/ static final MethodHandle ARRAY_CTOR = Lookup.PUBLIC.findStatic(Array.class, "newInstance",
221            MethodType.methodType(Object.class, Class.class, int.class));
222
223    static {
224        final Lookup lookup = new Lookup(MethodHandles.lookup());
225        GET_CLASS = lookup.findVirtual(StaticClass.class, "getRepresentedClass", MethodType.methodType(Class.class));
226        IS_CLASS = lookup.findOwnStatic("isClass", Boolean.TYPE, Class.class, Object.class);
227    }
228
229    @SuppressWarnings("unused")
230    private static boolean isClass(final Class<?> clazz, final Object obj) {
231        return obj instanceof StaticClass && ((StaticClass)obj).getRepresentedClass() == clazz;
232    }
233}
234