1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.juneau.commons.reflect;
18
19 import static org.apache.juneau.commons.utils.Utils.*;
20 import static org.apache.juneau.commons.utils.AssertionUtils.*;
21
22 import java.lang.reflect.*;
23
24 /**
25 * Abstract base class for reflection info classes that wrap {@link AccessibleObject}.
26 *
27 * <p>
28 * This class extends {@link ElementInfo} to provide common functionality for reflection elements that can be made
29 * accessible (fields, methods, and constructors). It mirrors the {@link AccessibleObject} API, allowing private
30 * members to be accessed via reflection.
31 *
32 * <h5 class='section'>Features:</h5>
33 * <ul class='spaced-list'>
34 * <li>Accessibility control - make private members accessible
35 * <li>Security exception handling - gracefully handles security exceptions
36 * <li>Accessibility checking - check if an element is accessible
37 * <li>Fluent API - methods return <c>this</c> for method chaining
38 * </ul>
39 *
40 * <h5 class='section'>Use Cases:</h5>
41 * <ul class='spaced-list'>
42 * <li>Accessing private fields, methods, or constructors
43 * <li>Building frameworks that need to work with non-public members
44 * <li>Testing scenarios where private members need to be accessed
45 * </ul>
46 *
47 * <h5 class='section'>Usage:</h5>
48 * <p class='bjava'>
49 * <jc>// Make accessible</jc>
50 * AccessibleInfo <jv>ai</jv> = ...;
51 * <jv>ai</jv>.setAccessible(); <jc>// Makes private member accessible</jc>
52 *
53 * <jc>// Check accessibility</jc>
54 * <jk>if</jk> (! <jv>ai</jv>.isAccessible()) {
55 * <jv>ai</jv>.setAccessible();
56 * }
57 *
58 * <jc>// Fluent API</jc>
59 * <jv>ai</jv>.accessible(); <jc>// Returns this after making accessible</jc>
60 * </p>
61 *
62 * <h5 class='section'>Security:</h5>
63 * <p>
64 * The {@link #setAccessible()} method attempts to make the element accessible and quietly ignores
65 * {@link SecurityException} if the security manager denies access. This allows code to work in
66 * both secure and non-secure environments.
67 *
68 * <h5 class='section'>See Also:</h5><ul>
69 * <li class='jc'>{@link ElementInfo} - Base class for all reflection elements
70 * <li class='jc'>{@link FieldInfo} - Field introspection
71 * <li class='jc'>{@link MethodInfo} - Method introspection
72 * <li class='jc'>{@link ConstructorInfo} - Constructor introspection
73 * <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauCommonsReflection">Reflection Package</a>
74 * </ul>
75 */
76 public abstract class AccessibleInfo extends ElementInfo {
77
78 private final AccessibleObject inner;
79
80 /**
81 * Constructor.
82 *
83 * @param inner The {@link AccessibleObject} being wrapped.
84 */
85 protected AccessibleInfo(AccessibleObject inner, int modifiers) {
86 super(modifiers);
87 this.inner = assertArgNotNull("inner", inner);
88 }
89
90 //-----------------------------------------------------------------------------------------------------------------
91 // Accessibility
92 //-----------------------------------------------------------------------------------------------------------------
93
94 /**
95 * Returns <jk>true</jk> if this object is accessible.
96 *
97 * <p>
98 * This method was added in Java 9. For earlier versions, this always returns <jk>false</jk>.
99 *
100 * <h5 class='section'>Example:</h5>
101 * <p class='bjava'>
102 * <jc>// Check if accessible without security checks</jc>
103 * <jk>if</jk> (!accessibleInfo.isAccessible()) {
104 * accessibleInfo.setAccessible();
105 * }
106 * </p>
107 *
108 * @return <jk>true</jk> if this object is accessible, <jk>false</jk> otherwise or if not supported.
109 */
110 public boolean isAccessible() {
111 return safeOpt(() -> (boolean)AccessibleObject.class.getMethod("isAccessible").invoke(inner)).orElse(false);
112 }
113
114 /**
115 * Attempts to call <code>x.setAccessible(<jk>true</jk>)</code> and quietly ignores security exceptions.
116 *
117 * @return <jk>true</jk> if call was successful.
118 */
119 public boolean setAccessible() {
120 return safeOpt(() -> { inner.setAccessible(true); return true;}).orElse(false);
121 }
122 }