Home | History | Annotate | Download | only in net 
      1 /*
      2  * Copyright (c) 2007,2011, 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 package java.net;
     26 
     27 import java.security.AccessController;
     28 
     29 /**
     30  * This class defines a factory for creating DatagramSocketImpls. It defaults
     31  * to creating plain DatagramSocketImpls, but may create other DatagramSocketImpls
     32  * by setting the impl.prefix system property.
     33  *
     34  * @author Chris Hegarty
     35  */
     36 
     37 class DefaultDatagramSocketImplFactory {
     38     static Class<?> prefixImplClass = null;
     39 
     40     static {
     41         String prefix = null;
     42         try {
     43             prefix = AccessController.doPrivileged(
     44                 new sun.security.action.GetPropertyAction("impl.prefix", null));
     45             if (prefix != null)
     46                 prefixImplClass = Class.forName("java.net."+prefix+"DatagramSocketImpl");
     47         } catch (Exception e) {
     48             System.err.println("Can't find class: java.net." +
     49                                 prefix +
     50                                 "DatagramSocketImpl: check impl.prefix property");
     51             //prefixImplClass = null;
     52         }
     53     }
     54 
     55     /**
     56      * Creates a new <code>DatagramSocketImpl</code> instance.
     57      *
     58      * @param   isMulticast     true if this impl if for a MutlicastSocket
     59      * @return  a new instance of a <code>DatagramSocketImpl</code>.
     60      */
     61     static DatagramSocketImpl createDatagramSocketImpl(boolean isMulticast /*unused on unix*/)
     62         throws SocketException {
     63         if (prefixImplClass != null) {
     64             try {
     65                 return (DatagramSocketImpl)prefixImplClass.newInstance();
     66             } catch (Exception e) {
     67                 throw new SocketException("can't instantiate DatagramSocketImpl");
     68             }
     69         } else {
     70             return new java.net.PlainDatagramSocketImpl();
     71         }
     72     }
     73 }
     74