1/*
2 * Copyright (C) 2012 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.reflect;
18
19import static com.google.common.base.Preconditions.checkNotNull;
20
21import java.lang.annotation.Annotation;
22import java.lang.reflect.AccessibleObject;
23import java.lang.reflect.Constructor;
24import java.lang.reflect.Field;
25import java.lang.reflect.Member;
26import java.lang.reflect.Method;
27import java.lang.reflect.Modifier;
28
29import javax.annotation.Nullable;
30
31/**
32 * Represents either a {@link Field}, a {@link Method} or a {@link Constructor}.
33 * Provides convenience methods such as {@link #isPublic} and {@link #isPackagePrivate}.
34 *
35 * @author Ben Yu
36 */
37class Element extends AccessibleObject implements Member {
38
39  private final AccessibleObject accessibleObject;
40  private final Member member;
41
42  <M extends AccessibleObject & Member> Element(M member) {
43    checkNotNull(member);
44    this.accessibleObject = member;
45    this.member = member;
46  }
47
48  public TypeToken<?> getOwnerType() {
49    return TypeToken.of(getDeclaringClass());
50  }
51
52  @Override public final boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
53    return accessibleObject.isAnnotationPresent(annotationClass);
54  }
55
56  @Override public final <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
57    return accessibleObject.getAnnotation(annotationClass);
58  }
59
60  @Override public final Annotation[] getAnnotations() {
61    return accessibleObject.getAnnotations();
62  }
63
64  @Override public final Annotation[] getDeclaredAnnotations() {
65    return accessibleObject.getDeclaredAnnotations();
66  }
67
68  @Override public final void setAccessible(boolean flag) throws SecurityException {
69    accessibleObject.setAccessible(flag);
70  }
71
72  @Override public final boolean isAccessible() {
73    return accessibleObject.isAccessible();
74  }
75
76  @Override public Class<?> getDeclaringClass() {
77    return member.getDeclaringClass();
78  }
79
80  @Override public final String getName() {
81    return member.getName();
82  }
83
84  @Override public final int getModifiers() {
85    return member.getModifiers();
86  }
87
88  @Override public final boolean isSynthetic() {
89    return member.isSynthetic();
90  }
91
92  /** Returns true if the element is public. */
93  public final boolean isPublic() {
94    return Modifier.isPublic(getModifiers());
95  }
96
97  /** Returns true if the element is protected. */
98  public final boolean isProtected() {
99    return Modifier.isProtected(getModifiers());
100  }
101
102  /** Returns true if the element is package-private. */
103  public final boolean isPackagePrivate() {
104    return !isPrivate() && !isPublic() && !isProtected();
105  }
106
107  /** Returns true if the element is private. */
108  public final boolean isPrivate() {
109    return Modifier.isPrivate(getModifiers());
110  }
111
112  /** Returns true if the element is static. */
113  public final boolean isStatic() {
114    return Modifier.isStatic(getModifiers());
115  }
116
117  /**
118   * Returns {@code true} if this method is final, per {@code Modifier.isFinal(getModifiers())}.
119   *
120   * <p>Note that a method may still be effectively "final", or non-overridable when it has no
121   * {@code final} keyword. For example, it could be private, or it could be declared by a final
122   * class. To tell whether a method is overridable, use {@link Invokable#isOverridable}.
123   */
124  public final boolean isFinal() {
125    return Modifier.isFinal(getModifiers());
126  }
127
128  /** Returns true if the method is abstract. */
129  public final boolean isAbstract() {
130    return Modifier.isAbstract(getModifiers());
131  }
132
133  /** Returns true if the element is native. */
134  public final boolean isNative() {
135    return Modifier.isNative(getModifiers());
136  }
137
138  /** Returns true if the method is synchronized. */
139  public final boolean isSynchronized() {
140    return Modifier.isSynchronized(getModifiers());
141  }
142
143  /** Returns true if the field is volatile. */
144  final boolean isVolatile() {
145    return Modifier.isVolatile(getModifiers());
146  }
147
148  /** Returns true if the field is transient. */
149  final boolean isTransient() {
150    return Modifier.isTransient(getModifiers());
151  }
152
153  @Override public boolean equals(@Nullable Object obj) {
154    if (obj instanceof Element) {
155      Element that = (Element) obj;
156      return getOwnerType().equals(that.getOwnerType()) && member.equals(that.member);
157    }
158    return false;
159  }
160
161  @Override public int hashCode() {
162    return member.hashCode();
163  }
164
165  @Override public String toString() {
166    return member.toString();
167  }
168}
169