Showing the changes to java/pkg/sun/net/ftp/FtpClientProvider.java (1 of 18352 files). Show all
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| 1 | /* | ||
| 2 | * Copyright (c) 2009, 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 sun.net.ftp; | ||
| 26 | |||
| 27 | import java.security.AccessController; | ||
| 28 | import java.security.PrivilegedAction; | ||
| 29 | import java.util.ServiceConfigurationError; | ||
| 30 | //import sun.misc.Service; | ||
| 31 | |||
| 32 | /** | ||
| 33 | * Service provider class for FtpClient. | ||
| 34 | * Sub-classes of FtpClientProvider provide an implementation of {@link FtpClient} | ||
| 35 | * and associated classes. Applications do not normally use this class directly. | ||
| 36 | * See {@link #provider() } for how providers are found and loaded. | ||
| 37 | * | ||
| 38 | * @since 1.7 | ||
| 39 | */ | ||
| 40 | public abstract class FtpClientProvider { | ||
| 41 | |||
| 42 | /** | ||
| 43 | * Creates a FtpClient from this provider. | ||
| 44 | * | ||
| 45 | * @return The created {@link FtpClient}. | ||
| 46 | */ | ||
| 47 | public abstract FtpClient createFtpClient(); | ||
| 48 | private static final Object lock = new Object(); | ||
| 49 | private static FtpClientProvider provider = null; | ||
| 50 | |||
| 51 | /** | ||
| 52 | * Initializes a new instance of this class. | ||
| 53 | * | ||
| 54 | * @throws SecurityException if a security manager is installed and it denies | ||
| 55 | * {@link RuntimePermission}<tt>("ftpClientProvider")</tt> | ||
| 56 | */ | ||
| 57 | protected FtpClientProvider() { | ||
| 58 | SecurityManager sm = System.getSecurityManager(); | ||
| 59 | if (sm != null) { | ||
| 60 | sm.checkPermission(new RuntimePermission("ftpClientProvider")); | ||
| 61 | } | ||
| 62 | } | ||
| 63 | |||
| 64 | private static boolean loadProviderFromProperty() { | ||
| 65 | String cm = System.getProperty("sun.net.ftpClientProvider"); | ||
| 66 | if (cm == null) { | ||
| 67 | return false; | ||
| 68 | } | ||
| 69 | try { | ||
| 70 | Class c = Class.forName(cm, true, null); | ||
| 71 | provider = (FtpClientProvider) c.newInstance(); | ||
| 72 | return true; | ||
| 73 | } catch (ClassNotFoundException x) { | ||
| 74 | throw new ServiceConfigurationError(x.toString()); | ||
| 75 | } catch (IllegalAccessException x) { | ||
| 76 | throw new ServiceConfigurationError(x.toString()); | ||
| 77 | } catch (InstantiationException x) { | ||
| 78 | throw new ServiceConfigurationError(x.toString()); | ||
| 79 | } catch (SecurityException x) { | ||
| 80 | throw new ServiceConfigurationError(x.toString()); | ||
| 81 | } | ||
| 82 | } | ||
| 83 | |||
| 84 | private static boolean loadProviderAsService() { | ||
| 85 | // Iterator i = Service.providers(FtpClientProvider.class, | ||
| 86 | // ClassLoader.getSystemClassLoader()); | ||
| 87 | // while (i.hasNext()) { | ||
| 88 | // try { | ||
| 89 | // provider = (FtpClientProvider) i.next(); | ||
| 90 | // return true; | ||
| 91 | // } catch (ServiceConfigurationError sce) { | ||
| 92 | // if (sce.getCause() instanceof SecurityException) { | ||
| 93 | // // Ignore, try next provider, if any | ||
| 94 | // continue; | ||
| 95 | // } | ||
| 96 | // throw sce; | ||
| 97 | // } | ||
| 98 | // } | ||
| 99 | return false; | ||
| 100 | } | ||
| 101 | |||
| 102 | /** | ||
| 103 | * Returns the system wide default FtpClientProvider for this invocation of | ||
| 104 | * the Java virtual machine. | ||
| 105 | * | ||
| 106 | * <p> The first invocation of this method locates the default provider | ||
| 107 | * object as follows: </p> | ||
| 108 | * | ||
| 109 | * <ol> | ||
| 110 | * | ||
| 111 | * <li><p> If the system property | ||
| 112 | * <tt>java.net.FtpClientProvider</tt> is defined then it is | ||
| 113 | * taken to be the fully-qualified name of a concrete provider class. | ||
| 114 | * The class is loaded and instantiated; if this process fails then an | ||
| 115 | * unspecified unchecked error or exception is thrown. </p></li> | ||
| 116 | * | ||
| 117 | * <li><p> If a provider class has been installed in a jar file that is | ||
| 118 | * visible to the system class loader, and that jar file contains a | ||
| 119 | * provider-configuration file named | ||
| 120 | * <tt>java.net.FtpClientProvider</tt> in the resource | ||
| 121 | * directory <tt>META-INF/services</tt>, then the first class name | ||
| 122 | * specified in that file is taken. The class is loaded and | ||
| 123 | * instantiated; if this process fails then an unspecified unchecked error or exception is | ||
| 124 | * thrown. </p></li> | ||
| 125 | * | ||
| 126 | * <li><p> Finally, if no provider has been specified by any of the above | ||
| 127 | * means then the system-default provider class is instantiated and the | ||
| 128 | * result is returned. </p></li> | ||
| 129 | * | ||
| 130 | * </ol> | ||
| 131 | * | ||
| 132 | * <p> Subsequent invocations of this method return the provider that was | ||
| 133 | * returned by the first invocation. </p> | ||
| 134 | * | ||
| 135 | * @return The system-wide default FtpClientProvider | ||
| 136 | */ | ||
| 137 | public static FtpClientProvider provider() { | ||
| 138 | synchronized (lock) { | ||
| 139 | if (provider != null) { | ||
| 140 | return provider; | ||
| 141 | } | ||
| 142 | return (FtpClientProvider) AccessController.doPrivileged( | ||
| 143 | new PrivilegedAction<Object>() { | ||
| 144 | |||
| 145 | public Object run() { | ||
| 146 | if (loadProviderFromProperty()) { | ||
| 147 | return provider; | ||
| 148 | } | ||
| 149 | if (loadProviderAsService()) { | ||
| 150 | return provider; | ||
| 151 | } | ||
| 152 | provider = new sun.net.ftp.impl.DefaultFtpClientProvider(); | ||
| 153 | return provider; | ||
| 154 | } | ||
| 155 | }); | ||
| 156 | } | ||
| 157 | } | ||
| 158 | } | ||