J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.net.httpserver.spi; |
| 27 | |
| 28 | import java.io.FileDescriptor; |
| 29 | import java.io.IOException; |
| 30 | import java.net.*; |
| 31 | import java.security.AccessController; |
| 32 | import java.security.PrivilegedAction; |
| 33 | import java.util.Iterator; |
| 34 | import sun.misc.Service; |
| 35 | import sun.misc.ServiceConfigurationError; |
| 36 | import sun.security.action.GetPropertyAction; |
| 37 | import com.sun.net.httpserver.*; |
| 38 | |
| 39 | /** |
| 40 | * Service provider class for HttpServer. |
| 41 | * Sub-classes of HttpServerProvider provide an implementation of {@link HttpServer} and |
| 42 | * associated classes. Applications do not normally use this class. |
| 43 | * See {@link #provider()} for how providers are found and loaded. |
| 44 | */ |
| 45 | public abstract class HttpServerProvider { |
| 46 | |
| 47 | /** |
| 48 | * creates a HttpServer from this provider |
| 49 | * @param addr the address to bind to. May be <code>null</code> |
| 50 | * @param backlog the socket backlog. A value of <code>zero</code> means the systems default |
| 51 | */ |
| 52 | public abstract HttpServer createHttpServer (InetSocketAddress addr, int backlog) throws IOException; |
| 53 | |
| 54 | /** |
| 55 | * creates a HttpsServer from this provider |
| 56 | * @param addr the address to bind to. May be <code>null</code> |
| 57 | * @param backlog the socket backlog. A value of <code>zero</code> means the systems default |
| 58 | */ |
| 59 | public abstract HttpsServer createHttpsServer (InetSocketAddress addr, int backlog) throws IOException; |
| 60 | |
| 61 | |
| 62 | |
| 63 | private static final Object lock = new Object(); |
| 64 | private static HttpServerProvider provider = null; |
| 65 | |
| 66 | /** |
| 67 | * Initializes a new instance of this class. </p> |
| 68 | * |
| 69 | * @throws SecurityException |
| 70 | * If a security manager has been installed and it denies |
| 71 | * {@link RuntimePermission}<tt>("httpServerProvider")</tt> |
| 72 | */ |
| 73 | protected HttpServerProvider() { |
| 74 | SecurityManager sm = System.getSecurityManager(); |
| 75 | if (sm != null) |
| 76 | sm.checkPermission(new RuntimePermission("httpServerProvider")); |
| 77 | } |
| 78 | |
| 79 | private static boolean loadProviderFromProperty() { |
| 80 | String cn = System.getProperty("com.sun.net.httpserver.HttpServerProvider"); |
| 81 | if (cn == null) |
| 82 | return false; |
| 83 | try { |
| 84 | Class c = Class.forName(cn, true, |
| 85 | ClassLoader.getSystemClassLoader()); |
| 86 | provider = (HttpServerProvider)c.newInstance(); |
| 87 | return true; |
| 88 | } catch (ClassNotFoundException x) { |
| 89 | throw new ServiceConfigurationError(x); |
| 90 | } catch (IllegalAccessException x) { |
| 91 | throw new ServiceConfigurationError(x); |
| 92 | } catch (InstantiationException x) { |
| 93 | throw new ServiceConfigurationError(x); |
| 94 | } catch (SecurityException x) { |
| 95 | throw new ServiceConfigurationError(x); |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | private static boolean loadProviderAsService() { |
| 100 | Iterator i = Service.providers(HttpServerProvider.class, |
| 101 | ClassLoader.getSystemClassLoader()); |
| 102 | for (;;) { |
| 103 | try { |
| 104 | if (!i.hasNext()) |
| 105 | return false; |
| 106 | provider = (HttpServerProvider)i.next(); |
| 107 | return true; |
| 108 | } catch (ServiceConfigurationError sce) { |
| 109 | if (sce.getCause() instanceof SecurityException) { |
| 110 | // Ignore the security exception, try the next provider |
| 111 | continue; |
| 112 | } |
| 113 | throw sce; |
| 114 | } |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Returns the system wide default HttpServerProvider for this invocation of |
| 120 | * the Java virtual machine. |
| 121 | * |
| 122 | * <p> The first invocation of this method locates the default provider |
| 123 | * object as follows: </p> |
| 124 | * |
| 125 | * <ol> |
| 126 | * |
| 127 | * <li><p> If the system property |
| 128 | * <tt>com.sun.net.httpserver.HttpServerProvider</tt> is defined then it is |
| 129 | * taken to be the fully-qualified name of a concrete provider class. |
| 130 | * The class is loaded and instantiated; if this process fails then an |
| 131 | * unspecified unchecked error or exception is thrown. </p></li> |
| 132 | * |
| 133 | * <li><p> If a provider class has been installed in a jar file that is |
| 134 | * visible to the system class loader, and that jar file contains a |
| 135 | * provider-configuration file named |
| 136 | * <tt>com.sun.net.httpserver.HttpServerProvider</tt> in the resource |
| 137 | * directory <tt>META-INF/services</tt>, then the first class name |
| 138 | * specified in that file is taken. The class is loaded and |
| 139 | * instantiated; if this process fails then an unspecified unchecked error or exception is |
| 140 | * thrown. </p></li> |
| 141 | * |
| 142 | * <li><p> Finally, if no provider has been specified by any of the above |
| 143 | * means then the system-default provider class is instantiated and the |
| 144 | * result is returned. </p></li> |
| 145 | * |
| 146 | * </ol> |
| 147 | * |
| 148 | * <p> Subsequent invocations of this method return the provider that was |
| 149 | * returned by the first invocation. </p> |
| 150 | * |
| 151 | * @return The system-wide default HttpServerProvider |
| 152 | */ |
| 153 | public static HttpServerProvider provider () { |
| 154 | synchronized (lock) { |
| 155 | if (provider != null) |
| 156 | return provider; |
| 157 | return (HttpServerProvider)AccessController |
| 158 | .doPrivileged(new PrivilegedAction<Object>() { |
| 159 | public Object run() { |
| 160 | if (loadProviderFromProperty()) |
| 161 | return provider; |
| 162 | if (loadProviderAsService()) |
| 163 | return provider; |
| 164 | provider = new sun.net.httpserver.DefaultHttpServerProvider(); |
| 165 | return provider; |
| 166 | } |
| 167 | }); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | } |