| /* |
| * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.net; |
| |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** |
| * This class defines a factory for creating DatagramSocketImpls. It defaults |
| * to creating plain DatagramSocketImpls, but may create other DatagramSocketImpls |
| * by setting the impl.prefix system property. |
| * |
| * For Windows versions lower than Windows Vista a TwoStacksPlainDatagramSocketImpl |
| * is always created. This impl supports IPv6 on these platform where available. |
| * |
| * On Windows platforms greater than Vista that support a dual layer TCP/IP stack |
| * a DualStackPlainDatagramSocketImpl is created for DatagramSockets. For MulticastSockets |
| * a TwoStacksPlainDatagramSocketImpl is always created. This is to overcome the lack |
| * of behavior defined for multicasting over a dual layer socket by the RFC. |
| * |
| * @author Chris Hegarty |
| */ |
| |
| class DefaultDatagramSocketImplFactory |
| { |
| private static final Class<?> prefixImplClass; |
| |
| /* the windows version. */ |
| private static float version; |
| |
| /* java.net.preferIPv4Stack */ |
| private static boolean preferIPv4Stack = false; |
| |
| /* If the version supports a dual stack TCP implementation */ |
| private static final boolean useDualStackImpl; |
| |
| /* sun.net.useExclusiveBind */ |
| private static String exclBindProp; |
| |
| /* True if exclusive binding is on for Windows */ |
| private static final boolean exclusiveBind; |
| |
| static { |
| Class<?> prefixImplClassLocal = null; |
| boolean useDualStackImplLocal = false; |
| boolean exclusiveBindLocal = true; |
| |
| // Determine Windows Version. |
| java.security.AccessController.doPrivileged( |
| new PrivilegedAction<Object>() { |
| public Object run() { |
| version = 0; |
| try { |
| version = Float.parseFloat(System.getProperties() |
| .getProperty("os.version")); |
| preferIPv4Stack = Boolean.parseBoolean( |
| System.getProperties() |
| .getProperty( |
| "java.net.preferIPv4Stack")); |
| exclBindProp = System.getProperty( |
| "sun.net.useExclusiveBind"); |
| } catch (NumberFormatException e) { |
| assert false : e; |
| } |
| return null; // nothing to return |
| } |
| }); |
| |
| // (version >= 6.0) implies Vista or greater. |
| if (version >= 6.0 && !preferIPv4Stack) { |
| useDualStackImplLocal = true; |
| } |
| if (exclBindProp != null) { |
| // sun.net.useExclusiveBind is true |
| exclusiveBindLocal = exclBindProp.length() == 0 ? true |
| : Boolean.parseBoolean(exclBindProp); |
| } else if (version < 6.0) { |
| exclusiveBindLocal = false; |
| } |
| |
| // impl.prefix |
| String prefix = null; |
| try { |
| prefix = AccessController.doPrivileged( |
| new sun.security.action.GetPropertyAction("impl.prefix", null)); |
| if (prefix != null) |
| prefixImplClassLocal = Class.forName("java.net."+prefix+"DatagramSocketImpl"); |
| } catch (Exception e) { |
| System.err.println("Can't find class: java.net." + |
| prefix + |
| "DatagramSocketImpl: check impl.prefix property"); |
| } |
| |
| prefixImplClass = prefixImplClassLocal; |
| useDualStackImpl = useDualStackImplLocal; |
| exclusiveBind = exclusiveBindLocal; |
| } |
| |
| /** |
| * Creates a new <code>DatagramSocketImpl</code> instance. |
| * |
| * @param isMulticast true if this impl is to be used for a MutlicastSocket |
| * @return a new instance of <code>PlainDatagramSocketImpl</code>. |
| */ |
| static DatagramSocketImpl createDatagramSocketImpl(boolean isMulticast) |
| throws SocketException { |
| if (prefixImplClass != null) { |
| try { |
| return (DatagramSocketImpl) prefixImplClass.newInstance(); |
| } catch (Exception e) { |
| throw new SocketException("can't instantiate DatagramSocketImpl"); |
| } |
| } else { |
| if (useDualStackImpl && !isMulticast) |
| return new DualStackPlainDatagramSocketImpl(exclusiveBind); |
| else |
| return new TwoStacksPlainDatagramSocketImpl(exclusiveBind && !isMulticast); |
| } |
| } |
| } |