StaticClassLinker.java revision 1551:f3b883bec2d0 
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
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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.StandardOperation;
95import jdk.dynalink.beans.GuardedInvocationComponent.ValidationType;
96import jdk.dynalink.linker.GuardedInvocation;
97import jdk.dynalink.linker.LinkRequest;
98import jdk.dynalink.linker.LinkerServices;
99import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
100import jdk.dynalink.linker.support.Lookup;
101
102/**
103 * Provides a linker for the {@link StaticClass} objects.
104 */
105class StaticClassLinker implements TypeBasedGuardingDynamicLinker {
106    private static final ClassValue<SingleClassStaticsLinker> linkers = new ClassValue<SingleClassStaticsLinker>() {
107        @Override
108        protected SingleClassStaticsLinker computeValue(final Class<?> clazz) {
109            return new SingleClassStaticsLinker(clazz);
110        }
111    };
112
113    private static class SingleClassStaticsLinker extends AbstractJavaLinker {
114        private final DynamicMethod constructor;
115
116        SingleClassStaticsLinker(final Class<?> clazz) {
117            super(clazz, IS_CLASS.bindTo(clazz));
118            // Map "staticClassObject.class" to StaticClass.getRepresentedClass(). Some adventurous soul could subclass
119            // StaticClass, so we use INSTANCE_OF validation instead of EXACT_CLASS.
120            setPropertyGetter("class", GET_CLASS, ValidationType.INSTANCE_OF);
121            constructor = createConstructorMethod(clazz);
122        }
123
124        /**
125         * Creates a dynamic method containing all overloads of a class' public constructor
126         * @param clazz the target class
127         * @return a dynamic method containing all overloads of a class' public constructor. If the class has no public
128         * constructors, returns null.
129         */
130        private static DynamicMethod createConstructorMethod(final Class<?> clazz) {
131            if(clazz.isArray()) {
132                final MethodHandle boundArrayCtor = ARRAY_CTOR.bindTo(clazz.getComponentType());
133                return new SimpleDynamicMethod(StaticClassIntrospector.editConstructorMethodHandle(
134                        boundArrayCtor.asType(boundArrayCtor.type().changeReturnType(clazz))), clazz, "<init>");
135            }
136            if(CheckRestrictedPackage.isRestrictedClass(clazz)) {
137                return null;
138            }
139            return createDynamicMethod(Arrays.asList(clazz.getConstructors()), clazz, "<init>");
140        }
141
142        @Override
143        FacetIntrospector createFacetIntrospector() {
144            return new StaticClassIntrospector(clazz);
145        }
146
147        @Override
148        public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices)
149                throws Exception {
150            final GuardedInvocation gi = super.getGuardedInvocation(request, linkerServices);
151            if(gi != null) {
152                return gi;
153            }
154            final CallSiteDescriptor desc = request.getCallSiteDescriptor();
155            if(NamedOperation.getBaseOperation(desc.getOperation()) == StandardOperation.NEW && constructor != null) {
156                final MethodHandle ctorInvocation = constructor.getInvocation(desc, linkerServices);
157                if(ctorInvocation != null) {
158                    return new GuardedInvocation(ctorInvocation, getClassGuard(desc.getMethodType()));
159                }
160            }
161            return null;
162        }
163
164        @Override
165        SingleDynamicMethod getConstructorMethod(final String signature) {
166            return constructor != null? constructor.getMethodForExactParamTypes(signature) : null;
167        }
168    }
169
170    static Object getConstructorMethod(final Class<?> clazz, final String signature) {
171        return linkers.get(clazz).getConstructorMethod(signature);
172    }
173
174    static Set<String> getReadableStaticPropertyNames(final Class<?> clazz) {
175        return linkers.get(clazz).getReadablePropertyNames();
176    }
177
178    static Set<String> getWritableStaticPropertyNames(final Class<?> clazz) {
179        return linkers.get(clazz).getWritablePropertyNames();
180    }
181
182    static Set<String> getStaticMethodNames(final Class<?> clazz) {
183        return linkers.get(clazz).getMethodNames();
184    }
185
186    @Override
187    public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
188        final Object receiver = request.getReceiver();
189        if(receiver instanceof StaticClass) {
190            return linkers.get(((StaticClass)receiver).getRepresentedClass()).getGuardedInvocation(request,
191                    linkerServices);
192        }
193        return null;
194    }
195
196    @Override
197    public boolean canLinkType(final Class<?> type) {
198        return type == StaticClass.class;
199    }
200
201    /*private*/ static final MethodHandle GET_CLASS;
202    /*private*/ static final MethodHandle IS_CLASS;
203    /*private*/ static final MethodHandle ARRAY_CTOR = Lookup.PUBLIC.findStatic(Array.class, "newInstance",
204            MethodType.methodType(Object.class, Class.class, int.class));
205
206    static {
207        final Lookup lookup = new Lookup(MethodHandles.lookup());
208        GET_CLASS = lookup.findVirtual(StaticClass.class, "getRepresentedClass", MethodType.methodType(Class.class));
209        IS_CLASS = lookup.findOwnStatic("isClass", Boolean.TYPE, Class.class, Object.class);
210    }
211
212    @SuppressWarnings("unused")
213    private static boolean isClass(final Class<?> clazz, final Object obj) {
214        return obj instanceof StaticClass && ((StaticClass)obj).getRepresentedClass() == clazz;
215    }
216}
217