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 | +} | |