1 /*
   2  * Copyright (c) 2003, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * A collection of utility methods used by the SelectorProvider.inheritedChannel
  26  * unit tests.
  27  */
  28 import java.net.*;
  29 import java.io.*;
  30 import java.nio.channels.*;
  31 import java.lang.reflect.*;
  32 
  33 public class Util {
  34 
  35     private static Object get(String className, String fieldName, Object o) throws Exception {
  36         Class cl = Class.forName(className);
  37         Field fld = cl.getDeclaredField(fieldName);
  38         fld.setAccessible(true);
  39         return fld.get(o);
  40     }
  41 
  42     private static int fdVal(FileDescriptor fdObj) throws Exception {
  43         Object fdVal = get("java.io.FileDescriptor", "fd", fdObj);
  44         return ((Integer)fdVal).intValue();
  45     }
  46 
  47     /*
  48      * Return the file descriptor underlying a given SocketChannel
  49      */
  50     public static int getFD(SocketChannel sc) {
  51         try {
  52             Object fdObj = get("sun.nio.ch.SocketChannelImpl", "fd", sc);
  53             return fdVal((FileDescriptor)fdObj);
  54         } catch (Exception x) {
  55             x.printStackTrace();
  56             throw new InternalError(x.getMessage());
  57         }
  58     }
  59 
  60     /*
  61      * Return the file descriptor underlying a given ServerSocketChannel
  62      */
  63     public static int getFD(ServerSocketChannel ssc) {
  64         try {
  65             Object fdObj = get("sun.nio.ch.ServerSocketChannelImpl", "fd", ssc);
  66             return fdVal((FileDescriptor)fdObj);
  67         } catch (Exception x) {
  68             x.printStackTrace();
  69             throw new InternalError(x.getMessage());
  70         }
  71     }
  72 
  73     /*
  74      * Return the file descriptor underlying a given DatagramChannel
  75      */
  76     public static int getFD(DatagramChannel dc) {
  77         try {
  78             Object fdObj = get("sun.nio.ch.DatagramChannelImpl", "fd", dc);
  79             return fdVal((FileDescriptor)fdObj);
  80         } catch (Exception x) {
  81             x.printStackTrace();
  82             throw new InternalError(x.getMessage());
  83         }
  84     }
  85 
  86     /*
  87      * Return the "java" command and any initial arguments to start the runtime
  88      * in the current configuration.
  89      */
  90     public static String javaCommand() {
  91         return System.getProperty("java.home") + File.separator + "bin" +
  92             File.separator + "java";
  93     }
  94 }