1 /* 2 * Copyright (c) 2000, 2006, 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 26 package java.rmi.server; 27 28 import java.net.MalformedURLException; 29 import java.net.URL; 30 31 /** 32 * <code>RMIClassLoaderSpi</code> is the service provider interface for 33 * <code>RMIClassLoader</code>. 34 * 35 * In particular, an <code>RMIClassLoaderSpi</code> instance provides an 36 * implementation of the following static methods of 37 * <code>RMIClassLoader</code>: 38 * 39 * <ul> 40 * 41 * <li>{@link RMIClassLoader#loadClass(URL,String)} 42 * <li>{@link RMIClassLoader#loadClass(String,String)} 43 * <li>{@link RMIClassLoader#loadClass(String,String,ClassLoader)} 44 * <li>{@link RMIClassLoader#loadProxyClass(String,String[],ClassLoader)} 45 * <li>{@link RMIClassLoader#getClassLoader(String)} 46 * <li>{@link RMIClassLoader#getClassAnnotation(Class)} 47 * 48 * </ul> 49 * 50 * When one of those methods is invoked, its behavior is to delegate 51 * to a corresponding method on an instance of this class. 52 * The details of how each method delegates to the provider instance is 53 * described in the documentation for each particular method. 54 * See the documentation for {@link RMIClassLoader} for a description 55 * of how a provider instance is chosen. 56 * 57 * @author Peter Jones 58 * @author Laird Dornin 59 * @see RMIClassLoader 60 * @since 1.4 61 */ 62 public abstract class RMIClassLoaderSpi { 63 64 /** 65 * Provides the implementation for 66 * {@link RMIClassLoader#loadClass(URL,String)}, 67 * {@link RMIClassLoader#loadClass(String,String)}, and 68 * {@link RMIClassLoader#loadClass(String,String,ClassLoader)}. 69 * 70 * Loads a class from a codebase URL path, optionally using the 71 * supplied loader. 72 * 73 * Typically, a provider implementation will attempt to 74 * resolve the named class using the given <code>defaultLoader</code>, 75 * if specified, before attempting to resolve the class from the 76 * codebase URL path. 77 * 78 * <p>An implementation of this method must either return a class 79 * with the given name or throw an exception. 80 * 81 * @param codebase the list of URLs (separated by spaces) to load 82 * the class from, or <code>null</code> 83 * 84 * @param name the name of the class to load 85 * 86 * @param defaultLoader additional contextual class loader 87 * to use, or <code>null</code> 88 * 89 * @return the <code>Class</code> object representing the loaded class 90 * 91 * @throws MalformedURLException if <code>codebase</code> is 92 * non-<code>null</code> and contains an invalid URL, or 93 * if <code>codebase</code> is <code>null</code> and a provider-specific 94 * URL used to load classes is invalid 95 * 96 * @throws ClassNotFoundException if a definition for the class 97 * could not be found at the specified location 98 */ loadClass(String codebase, String name, ClassLoader defaultLoader)99 public abstract Class<?> loadClass(String codebase, String name, 100 ClassLoader defaultLoader) 101 throws MalformedURLException, ClassNotFoundException; 102 103 /** 104 * Provides the implementation for 105 * {@link RMIClassLoader#loadProxyClass(String,String[],ClassLoader)}. 106 * 107 * Loads a dynamic proxy class (see {@link java.lang.reflect.Proxy} 108 * that implements a set of interfaces with the given names 109 * from a codebase URL path, optionally using the supplied loader. 110 * 111 * <p>An implementation of this method must either return a proxy 112 * class that implements the named interfaces or throw an exception. 113 * 114 * @param codebase the list of URLs (space-separated) to load 115 * classes from, or <code>null</code> 116 * 117 * @param interfaces the names of the interfaces for the proxy class 118 * to implement 119 * 120 * @return a dynamic proxy class that implements the named interfaces 121 * 122 * @param defaultLoader additional contextual class loader 123 * to use, or <code>null</code> 124 * 125 * @throws MalformedURLException if <code>codebase</code> is 126 * non-<code>null</code> and contains an invalid URL, or 127 * if <code>codebase</code> is <code>null</code> and a provider-specific 128 * URL used to load classes is invalid 129 * 130 * @throws ClassNotFoundException if a definition for one of 131 * the named interfaces could not be found at the specified location, 132 * or if creation of the dynamic proxy class failed (such as if 133 * {@link java.lang.reflect.Proxy#getProxyClass(ClassLoader,Class[])} 134 * would throw an <code>IllegalArgumentException</code> for the given 135 * interface list) 136 */ loadProxyClass(String codebase, String[] interfaces, ClassLoader defaultLoader)137 public abstract Class<?> loadProxyClass(String codebase, 138 String[] interfaces, 139 ClassLoader defaultLoader) 140 throws MalformedURLException, ClassNotFoundException; 141 142 /** 143 * Provides the implementation for 144 * {@link RMIClassLoader#getClassLoader(String)}. 145 * 146 * Returns a class loader that loads classes from the given codebase 147 * URL path. 148 * 149 * <p>If there is a security manger, its <code>checkPermission</code> 150 * method will be invoked with a 151 * <code>RuntimePermission("getClassLoader")</code> permission; 152 * this could result in a <code>SecurityException</code>. 153 * The implementation of this method may also perform further security 154 * checks to verify that the calling context has permission to connect 155 * to all of the URLs in the codebase URL path. 156 * 157 * @param codebase the list of URLs (space-separated) from which 158 * the returned class loader will load classes from, or <code>null</code> 159 * 160 * @return a class loader that loads classes from the given codebase URL 161 * path 162 * 163 * @throws MalformedURLException if <code>codebase</code> is 164 * non-<code>null</code> and contains an invalid URL, or 165 * if <code>codebase</code> is <code>null</code> and a provider-specific 166 * URL used to identify the class loader is invalid 167 * 168 * @throws SecurityException if there is a security manager and the 169 * invocation of its <code>checkPermission</code> method fails, or 170 * if the caller does not have permission to connect to all of the 171 * URLs in the codebase URL path 172 */ getClassLoader(String codebase)173 public abstract ClassLoader getClassLoader(String codebase) 174 throws MalformedURLException; // SecurityException 175 176 /** 177 * Provides the implementation for 178 * {@link RMIClassLoader#getClassAnnotation(Class)}. 179 * 180 * Returns the annotation string (representing a location for 181 * the class definition) that RMI will use to annotate the class 182 * descriptor when marshalling objects of the given class. 183 * 184 * @param cl the class to obtain the annotation for 185 * 186 * @return a string to be used to annotate the given class when 187 * it gets marshalled, or <code>null</code> 188 * 189 * @throws NullPointerException if <code>cl</code> is <code>null</code> 190 */ getClassAnnotation(Class<?> cl)191 public abstract String getClassAnnotation(Class<?> cl); 192 } 193