1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
/* * @(#)ClassLoaderRepository.java 1.20 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.management.loading; import javax.management.MBeanServer; // for Javadoc /** * <p>Instances of this interface are used to keep the list of ClassLoaders * registered in an MBean Server. * They provide the necessary methods to load classes using the registered * ClassLoaders.</p> * * <p>The first ClassLoader in a <code>ClassLoaderRepository</code> is * always the MBean Server's own ClassLoader.</p> * * <p>When an MBean is registered in an MBean Server, if it is of a * subclass of {@link java.lang.ClassLoader} and if it does not * implement the interface {@link PrivateClassLoader}, it is added to * the end of the MBean Server's <code>ClassLoaderRepository</code>. * If it is subsequently unregistered from the MBean Server, it is * removed from the <code>ClassLoaderRepository</code>.</p> * * <p>The order of MBeans in the <code>ClassLoaderRepository</code> is * significant. For any two MBeans <em>X</em> and <em>Y</em> in the * <code>ClassLoaderRepository</code>, <em>X</em> must appear before * <em>Y</em> if the registration of <em>X</em> was completed before * the registration of <em>Y</em> started. If <em>X</em> and * <em>Y</em> were registered concurrently, their order is * indeterminate. The registration of an MBean corresponds to the * call to {@link MBeanServer#registerMBean} or one of the {@link * MBeanServer}<code>.createMBean</code> methods.</p> * * @see javax.management.MBeanServerFactory * * @since 1.5 * @since.unbundled JMX 1.1 */ public interface ClassLoaderRepository { /** * <p>Load the given class name through the list of class loaders. * Each ClassLoader in turn from the ClassLoaderRepository is * asked to load the class via its {@link * ClassLoader#loadClass(String)} method. If it successfully * returns a {@link Class} object, that is the result of this * method. If it throws a {@link ClassNotFoundException}, the * search continues with the next ClassLoader. If it throws * another exception, the exception is propagated from this * method. If the end of the list is reached, a {@link * ClassNotFoundException} is thrown.</p> * * @param className The name of the class to be loaded. * * @return the loaded class. * * @exception ClassNotFoundException The specified class could not be * found. */ public Class<?> loadClass(String className) throws ClassNotFoundException; /** * <p>Load the given class name through the list of class loaders, * excluding the given one. Each ClassLoader in turn from the * ClassLoaderRepository, except <code>exclude</code>, is asked to * load the class via its {@link ClassLoader#loadClass(String)} * method. If it successfully returns a {@link Class} object, * that is the result of this method. If it throws a {@link * ClassNotFoundException}, the search continues with the next * ClassLoader. If it throws another exception, the exception is * propagated from this method. If the end of the list is * reached, a {@link ClassNotFoundException} is thrown.</p> * * <p>Be aware that if a ClassLoader in the ClassLoaderRepository * calls this method from its {@link ClassLoader#loadClass(String) * loadClass} method, it exposes itself to a deadlock if another * ClassLoader in the ClassLoaderRepository does the same thing at * the same time. The {@link #loadClassBefore} method is * recommended to avoid the risk of deadlock.</p> * * @param className The name of the class to be loaded. * @param exclude The class loader to be excluded. May be null, * in which case this method is equivalent to {@link #loadClass * loadClass(className)}. * * @return the loaded class. * * @exception ClassNotFoundException The specified class could not * be found. */ public Class<?> loadClassWithout(ClassLoader exclude, String className) throws ClassNotFoundException; /** * <p>Load the given class name through the list of class loaders, * stopping at the given one. Each ClassLoader in turn from the * ClassLoaderRepository is asked to load the class via its {@link * ClassLoader#loadClass(String)} method. If it successfully * returns a {@link Class} object, that is the result of this * method. If it throws a {@link ClassNotFoundException}, the * search continues with the next ClassLoader. If it throws * another exception, the exception is propagated from this * method. If the search reaches <code>stop</code> or the end of * the list, a {@link ClassNotFoundException} is thrown.</p> * * <p>Typically this method is called from the {@link * ClassLoader#loadClass(String) loadClass} method of * <code>stop</code>, to consult loaders that appear before it * in the <code>ClassLoaderRepository</code>. By stopping the * search as soon as <code>stop</code> is reached, a potential * deadlock with concurrent class loading is avoided.</p> * * @param className The name of the class to be loaded. * @param stop The class loader at which to stop. May be null, in * which case this method is equivalent to {@link #loadClass(String) * loadClass(className)}. * * @return the loaded class. * * @exception ClassNotFoundException The specified class could not * be found. * * @since.unbundled JMX 1.2 */ public Class<?> loadClassBefore(ClassLoader stop, String className) throws ClassNotFoundException; }