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 */
25package java.net;
26
27import 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
37class 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