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1   /*
2    * Copyright 2017 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. 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, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.util.internal;
17  
18  import java.lang.reflect.AccessibleObject;
19  
20  public final class ReflectionUtil {
21  
22      private ReflectionUtil() { }
23  
24      /**
25       * Try to call {@link AccessibleObject#setAccessible(boolean)} but will catch any {@link SecurityException} and
26       * {@link java.lang.reflect.InaccessibleObjectException} and return it.
27       * The caller must check if it returns {@code null} and if not handle the returned exception.
28       */
29      public static Throwable trySetAccessible(AccessibleObject object, boolean checkAccessible) {
30          if (checkAccessible && !PlatformDependent0.isExplicitTryReflectionSetAccessible()) {
31              return new UnsupportedOperationException("Reflective setAccessible(true) disabled");
32          }
33          try {
34              object.setAccessible(true);
35              return null;
36          } catch (SecurityException e) {
37              return e;
38          } catch (RuntimeException e) {
39              return handleInaccessibleObjectException(e);
40          }
41      }
42  
43      private static RuntimeException handleInaccessibleObjectException(RuntimeException e) {
44          // JDK 9 can throw an inaccessible object exception here; since Netty compiles
45          // against JDK 7 and this exception was only added in JDK 9, we have to weakly
46          // check the type
47          if ("java.lang.reflect.InaccessibleObjectException".equals(e.getClass().getName())) {
48              return e;
49          }
50          throw e;
51      }
52  }