1 /*
   2  * Copyright (c) 2017, 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.javafx.fxml;
  27 
  28 import com.sun.javafx.reflect.MethodUtil;
  29 import java.lang.reflect.InvocationTargetException;
  30 import java.lang.reflect.Method;
  31 import java.security.AccessController;
  32 import java.security.PrivilegedAction;
  33 import sun.reflect.misc.ReflectUtil;
  34 
  35 /**
  36  * Utility class to wrap method invocation.
  37  */
  38 public class MethodHelper {
  39     private static final boolean logAccessErrors
  40             = AccessController.doPrivileged((PrivilegedAction<Boolean>) ()
  41                     -> Boolean.getBoolean("sun.reflect.debugModuleAccessChecks"));
  42 
  43     private static final Module trampolineModule = MethodUtil.getTrampolineModule();
  44 
  45     public static Object invoke(Method m, Object obj, Object[] params)
  46             throws InvocationTargetException, IllegalAccessException {
  47 
  48         // Check that the class in question is in a package that is open to
  49         // this module (or exported unconditionally). If so, then we will open
  50         // the containing package to the unnamed trampoline module. If not,
  51         // we will throw an IllegalAccessException in order to generate a
  52         // clearer error message.
  53         final Class<?> clazz = m.getDeclaringClass();
  54         final String packageName = clazz.getPackage().getName();
  55         final Module module = clazz.getModule();
  56         final Module thisModule = MethodHelper.class.getModule();
  57         try {
  58             // Verify that the module being called either exports the package
  59             // in question unconditionally or opens the package in question to
  60             // this module.
  61             if (!module.isExported(packageName)) {
  62                 if (!module.isOpen(packageName, thisModule)) {
  63                     throw new IllegalAccessException(
  64                             "class " + MethodHelper.class.getName()
  65                             + " cannot access class " + clazz.getName()
  66                             + " (in module " + module.getName()
  67                             + ") because module " + module.getName()
  68                             + " does not open " + packageName
  69                             + " to " + thisModule.getName());
  70                 }
  71                 if (!module.isOpen(packageName, trampolineModule)) {
  72                     ReflectUtil.checkPackageAccess(packageName);
  73                     module.addOpens(packageName, trampolineModule);
  74                 }
  75             }
  76         } catch (IllegalAccessException ex) {
  77             if (logAccessErrors) {
  78                 ex.printStackTrace(System.err);
  79             }
  80             throw ex;
  81         }
  82 
  83         return MethodUtil.invoke(m, obj, params);
  84     }
  85 
  86     // Utility class, do not instantiate
  87     private MethodHelper() {
  88     }
  89 
  90 }