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.reflect.Field;
88import java.lang.reflect.Member;
89import java.lang.reflect.Method;
90import java.lang.reflect.Modifier;
91import java.util.ArrayList;
92import java.util.Collection;
93import java.util.Collections;
94import java.util.Map;
95import jdk.dynalink.linker.support.Lookup;
96
97/**
98 * Base for classes that expose class field and method information to an {@link AbstractJavaLinker}. There are
99 * subclasses for instance (bean) and static facet of a class.
100 */
101abstract class FacetIntrospector {
102    private final Class<?> clazz;
103    private final boolean instance;
104    private final boolean isRestricted;
105
106    protected final AccessibleMembersLookup membersLookup;
107
108    FacetIntrospector(final Class<?> clazz, final boolean instance) {
109        this.clazz = clazz;
110        this.instance = instance;
111        isRestricted = CheckRestrictedPackage.isRestrictedClass(clazz);
112        membersLookup = new AccessibleMembersLookup(clazz, instance);
113    }
114
115    /**
116     * Returns getters for inner classes.
117     * @return getters for inner classes.
118     */
119    abstract Map<String, MethodHandle> getInnerClassGetters();
120
121    /**
122     * Returns the fields for the class facet.
123     * @return the fields for the class facet.
124     */
125    Collection<Field> getFields() {
126        if(isRestricted) {
127            // NOTE: we can't do anything here. Unlike with methods in AccessibleMethodsLookup, we can't just return
128            // the fields from a public superclass, because this class might define same-named fields which will shadow
129            // the superclass fields, and we have no way to know if they do, since we're denied invocation of
130            // getFields(). Therefore, the only correct course of action is to not expose any public fields from a class
131            // defined in a restricted package.
132            return Collections.emptySet();
133        }
134
135        final Field[] fields = clazz.getFields();
136        final Collection<Field> cfields = new ArrayList<>(fields.length);
137        for(final Field field: fields) {
138            final boolean isStatic = Modifier.isStatic(field.getModifiers());
139            if(isStatic && clazz != field.getDeclaringClass()) {
140                // ignore inherited static fields
141                continue;
142            }
143
144            if(instance != isStatic && isAccessible(field)) {
145                cfields.add(field);
146            }
147        }
148        return cfields;
149    }
150
151    boolean isAccessible(final Member m) {
152        final Class<?> declaring = m.getDeclaringClass();
153        // (declaring == clazz) is just an optimization - we're calling this only from code that operates on a
154        // non-restricted class, so if the declaring class is identical to the class being inspected, then forego
155        // a potentially expensive restricted-package check.
156        return declaring == clazz || !CheckRestrictedPackage.isRestrictedClass(declaring);
157    }
158
159    /**
160     * Returns all the methods in the facet.
161     * @return all the methods in the facet.
162     */
163    Collection<Method> getMethods() {
164        return membersLookup.getMethods();
165    }
166
167
168    MethodHandle unreflectGetter(final Field field) {
169        return editMethodHandle(Lookup.PUBLIC.unreflectGetter(field));
170    }
171
172    MethodHandle unreflectSetter(final Field field) {
173        return editMethodHandle(Lookup.PUBLIC.unreflectSetter(field));
174    }
175
176    /**
177     * Returns an edited method handle. A facet might need to edit an unreflected method handle before it is usable with
178     * the facet. By default, returns the passed method handle unchanged. The class' static facet will introduce a
179     * dropArguments.
180     * @param mh the method handle to edit.
181     * @return the edited method handle.
182     */
183    abstract MethodHandle editMethodHandle(MethodHandle mh);
184}
185