1 /*
   2  * Copyright (c) 2013, 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 com.sun.xml.internal.bind.v2.runtime;
  27 
  28 import com.sun.xml.internal.bind.v2.model.nav.Navigator;
  29 
  30 import java.lang.reflect.Field;
  31 import java.lang.reflect.InvocationTargetException;
  32 import java.lang.reflect.Method;
  33 import java.lang.reflect.Type;
  34 import java.security.AccessController;
  35 import java.security.PrivilegedAction;
  36 import java.util.logging.Level;
  37 import java.util.logging.Logger;
  38 
  39 /**
  40  * Utils class.
  41  *
  42  * WARNING: If you are doing any changes don't forget to change other Utils classes in different packages.
  43  *
  44  * Has *package private* access to avoid inappropriate usage.
  45  */
  46 final class Utils {
  47 
  48     private static final Logger LOGGER = Logger.getLogger(Utils.class.getName());
  49 
  50     /**
  51      * static ReflectionNavigator field to avoid usage of reflection every time we use it.
  52      */
  53     static final Navigator<Type, Class, Field, Method> REFLECTION_NAVIGATOR;
  54 
  55     static { // we statically initializing REFLECTION_NAVIGATOR property
  56         try {
  57             final Class refNav = Class.forName("com.sun.xml.internal.bind.v2.model.nav.ReflectionNavigator");
  58 
  59             // requires accessClassInPackage privilege
  60             final Method getInstance = AccessController.doPrivileged(
  61                     new PrivilegedAction<Method>() {
  62                         @Override
  63                         public Method run() {
  64                             try {
  65                                 Method getInstance = refNav.getDeclaredMethod("getInstance");
  66                                 getInstance.setAccessible(true);
  67                                 return getInstance;
  68                             } catch (NoSuchMethodException e) {
  69                                 throw new IllegalStateException("ReflectionNavigator.getInstance can't be found");
  70                             }
  71                         }
  72                     }
  73             );
  74 
  75             //noinspection unchecked
  76             REFLECTION_NAVIGATOR = (Navigator<Type, Class, Field, Method>) getInstance.invoke(null);
  77         } catch (ClassNotFoundException e) {
  78             throw new IllegalStateException("Can't find ReflectionNavigator class");
  79         } catch (InvocationTargetException e) {
  80             throw new IllegalStateException("ReflectionNavigator.getInstance throws the exception");
  81         } catch (IllegalAccessException e) {
  82             throw new IllegalStateException("ReflectionNavigator.getInstance method is inaccessible");
  83         } catch (SecurityException e) {
  84             LOGGER.log(Level.FINE, "Unable to access ReflectionNavigator.getInstance", e);
  85             throw e;
  86         }
  87     }
  88 
  89     /**
  90      * private constructor to avoid util class instantiating
  91      */
  92     private Utils() {
  93     }
  94 }