1 /*
   2  * Copyright (c) 2000, 2014, 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 package sun.nio.ch;
  27 
  28 import java.io.*;
  29 import java.lang.reflect.*;
  30 import java.security.AccessController;
  31 import java.security.PrivilegedAction;
  32 
  33 
  34 class Reflect {                                 // package-private
  35 
  36     private Reflect() { }
  37 
  38     private static class ReflectionError extends Error {
  39         @java.io.Serial
  40         private static final long serialVersionUID = -8659519328078164097L;
  41         ReflectionError(Throwable x) {
  42             super(x);
  43         }
  44     }
  45 
  46     private static void setAccessible(final AccessibleObject ao) {
  47         AccessController.doPrivileged(new PrivilegedAction<Void>() {
  48                 public Void run() {
  49                     ao.setAccessible(true);
  50                     return null;
  51                 }});
  52     }
  53 
  54     static Constructor<?> lookupConstructor(String className,
  55                                             Class<?>[] paramTypes)
  56     {
  57         try {
  58             Class<?> cl = Class.forName(className);
  59             Constructor<?> c = cl.getDeclaredConstructor(paramTypes);
  60             setAccessible(c);
  61             return c;
  62         } catch (ClassNotFoundException | NoSuchMethodException x) {
  63             throw new ReflectionError(x);
  64         }
  65     }
  66 
  67     static Object invoke(Constructor<?> c, Object[] args) {
  68         try {
  69             return c.newInstance(args);
  70         } catch (InstantiationException |
  71                  IllegalAccessException |
  72                  InvocationTargetException x) {
  73             throw new ReflectionError(x);
  74         }
  75     }
  76 
  77     static Method lookupMethod(String className,
  78                                String methodName,
  79                                Class<?>... paramTypes)
  80     {
  81         try {
  82             Class<?> cl = Class.forName(className);
  83             Method m = cl.getDeclaredMethod(methodName, paramTypes);
  84             setAccessible(m);
  85             return m;
  86         } catch (ClassNotFoundException | NoSuchMethodException x) {
  87             throw new ReflectionError(x);
  88         }
  89     }
  90 
  91     static Object invoke(Method m, Object ob, Object[] args) {
  92         try {
  93             return m.invoke(ob, args);
  94         } catch (IllegalAccessException | InvocationTargetException x) {
  95             throw new ReflectionError(x);
  96         }
  97     }
  98 
  99     static Object invokeIO(Method m, Object ob, Object[] args)
 100         throws IOException
 101     {
 102         try {
 103             return m.invoke(ob, args);
 104         } catch (IllegalAccessException x) {
 105             throw new ReflectionError(x);
 106         } catch (InvocationTargetException x) {
 107             if (IOException.class.isInstance(x.getCause()))
 108                 throw (IOException)x.getCause();
 109             throw new ReflectionError(x);
 110         }
 111     }
 112 
 113     static Field lookupField(String className, String fieldName) {
 114         try {
 115             Class<?> cl = Class.forName(className);
 116             Field f = cl.getDeclaredField(fieldName);
 117             setAccessible(f);
 118             return f;
 119         } catch (ClassNotFoundException | NoSuchFieldException x) {
 120             throw new ReflectionError(x);
 121         }
 122     }
 123 
 124     static Object get(Object ob, Field f) {
 125         try {
 126             return f.get(ob);
 127         } catch (IllegalAccessException x) {
 128             throw new ReflectionError(x);
 129         }
 130     }
 131 
 132     static Object get(Field f) {
 133         return get(null, f);
 134     }
 135 
 136     static void set(Object ob, Field f, Object val) {
 137         try {
 138             f.set(ob, val);
 139         } catch (IllegalAccessException x) {
 140             throw new ReflectionError(x);
 141         }
 142     }
 143 
 144     static void setInt(Object ob, Field f, int val) {
 145         try {
 146             f.setInt(ob, val);
 147         } catch (IllegalAccessException x) {
 148             throw new ReflectionError(x);
 149         }
 150     }
 151 
 152     static void setBoolean(Object ob, Field f, boolean val) {
 153         try {
 154             f.setBoolean(ob, val);
 155         } catch (IllegalAccessException x) {
 156             throw new ReflectionError(x);
 157         }
 158     }
 159 
 160 }