| /* |
| * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.lang.reflect; |
| |
| import java.lang.ref.Reference; |
| import java.lang.ref.WeakReference; |
| import java.security.AccessController; |
| import java.security.Permission; |
| import java.security.PrivilegedAction; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.List; |
| import java.util.WeakHashMap; |
| import sun.misc.ProxyGenerator; |
| import sun.reflect.CallerSensitive; |
| import sun.reflect.Reflection; |
| import sun.reflect.misc.ReflectUtil; |
| import sun.security.util.SecurityConstants; |
| |
| /** |
| * {@code Proxy} provides static methods for creating dynamic proxy |
| * classes and instances, and it is also the superclass of all |
| * dynamic proxy classes created by those methods. |
| * |
| * <p>To create a proxy for some interface {@code Foo}: |
| * <pre> |
| * InvocationHandler handler = new MyInvocationHandler(...); |
| * Class proxyClass = Proxy.getProxyClass( |
| * Foo.class.getClassLoader(), new Class[] { Foo.class }); |
| * Foo f = (Foo) proxyClass. |
| * getConstructor(new Class[] { InvocationHandler.class }). |
| * newInstance(new Object[] { handler }); |
| * </pre> |
| * or more simply: |
| * <pre> |
| * Foo f = (Foo) Proxy.newProxyInstance(Foo.class.getClassLoader(), |
| * new Class[] { Foo.class }, |
| * handler); |
| * </pre> |
| * |
| * <p>A <i>dynamic proxy class</i> (simply referred to as a <i>proxy |
| * class</i> below) is a class that implements a list of interfaces |
| * specified at runtime when the class is created, with behavior as |
| * described below. |
| * |
| * A <i>proxy interface</i> is such an interface that is implemented |
| * by a proxy class. |
| * |
| * A <i>proxy instance</i> is an instance of a proxy class. |
| * |
| * Each proxy instance has an associated <i>invocation handler</i> |
| * object, which implements the interface {@link InvocationHandler}. |
| * A method invocation on a proxy instance through one of its proxy |
| * interfaces will be dispatched to the {@link InvocationHandler#invoke |
| * invoke} method of the instance's invocation handler, passing the proxy |
| * instance, a {@code java.lang.reflect.Method} object identifying |
| * the method that was invoked, and an array of type {@code Object} |
| * containing the arguments. The invocation handler processes the |
| * encoded method invocation as appropriate and the result that it |
| * returns will be returned as the result of the method invocation on |
| * the proxy instance. |
| * |
| * <p>A proxy class has the following properties: |
| * |
| * <ul> |
| * <li>Proxy classes are public, final, and not abstract. |
| * |
| * <li>The unqualified name of a proxy class is unspecified. The space |
| * of class names that begin with the string {@code "$Proxy"} |
| * should be, however, reserved for proxy classes. |
| * |
| * <li>A proxy class extends {@code java.lang.reflect.Proxy}. |
| * |
| * <li>A proxy class implements exactly the interfaces specified at its |
| * creation, in the same order. |
| * |
| * <li>If a proxy class implements a non-public interface, then it will |
| * be defined in the same package as that interface. Otherwise, the |
| * package of a proxy class is also unspecified. Note that package |
| * sealing will not prevent a proxy class from being successfully defined |
| * in a particular package at runtime, and neither will classes already |
| * defined by the same class loader and the same package with particular |
| * signers. |
| * |
| * <li>Since a proxy class implements all of the interfaces specified at |
| * its creation, invoking {@code getInterfaces} on its |
| * {@code Class} object will return an array containing the same |
| * list of interfaces (in the order specified at its creation), invoking |
| * {@code getMethods} on its {@code Class} object will return |
| * an array of {@code Method} objects that include all of the |
| * methods in those interfaces, and invoking {@code getMethod} will |
| * find methods in the proxy interfaces as would be expected. |
| * |
| * <li>The {@link Proxy#isProxyClass Proxy.isProxyClass} method will |
| * return true if it is passed a proxy class-- a class returned by |
| * {@code Proxy.getProxyClass} or the class of an object returned by |
| * {@code Proxy.newProxyInstance}-- and false otherwise. |
| * |
| * <li>The {@code java.security.ProtectionDomain} of a proxy class |
| * is the same as that of system classes loaded by the bootstrap class |
| * loader, such as {@code java.lang.Object}, because the code for a |
| * proxy class is generated by trusted system code. This protection |
| * domain will typically be granted |
| * {@code java.security.AllPermission}. |
| * |
| * <li>Each proxy class has one public constructor that takes one argument, |
| * an implementation of the interface {@link InvocationHandler}, to set |
| * the invocation handler for a proxy instance. Rather than having to use |
| * the reflection API to access the public constructor, a proxy instance |
| * can be also be created by calling the {@link Proxy#newProxyInstance |
| * Proxy.newProxyInstance} method, which combines the actions of calling |
| * {@link Proxy#getProxyClass Proxy.getProxyClass} with invoking the |
| * constructor with an invocation handler. |
| * </ul> |
| * |
| * <p>A proxy instance has the following properties: |
| * |
| * <ul> |
| * <li>Given a proxy instance {@code proxy} and one of the |
| * interfaces implemented by its proxy class {@code Foo}, the |
| * following expression will return true: |
| * <pre> |
| * {@code proxy instanceof Foo} |
| * </pre> |
| * and the following cast operation will succeed (rather than throwing |
| * a {@code ClassCastException}): |
| * <pre> |
| * {@code (Foo) proxy} |
| * </pre> |
| * |
| * <li>Each proxy instance has an associated invocation handler, the one |
| * that was passed to its constructor. The static |
| * {@link Proxy#getInvocationHandler Proxy.getInvocationHandler} method |
| * will return the invocation handler associated with the proxy instance |
| * passed as its argument. |
| * |
| * <li>An interface method invocation on a proxy instance will be |
| * encoded and dispatched to the invocation handler's {@link |
| * InvocationHandler#invoke invoke} method as described in the |
| * documentation for that method. |
| * |
| * <li>An invocation of the {@code hashCode}, |
| * {@code equals}, or {@code toString} methods declared in |
| * {@code java.lang.Object} on a proxy instance will be encoded and |
| * dispatched to the invocation handler's {@code invoke} method in |
| * the same manner as interface method invocations are encoded and |
| * dispatched, as described above. The declaring class of the |
| * {@code Method} object passed to {@code invoke} will be |
| * {@code java.lang.Object}. Other public methods of a proxy |
| * instance inherited from {@code java.lang.Object} are not |
| * overridden by a proxy class, so invocations of those methods behave |
| * like they do for instances of {@code java.lang.Object}. |
| * </ul> |
| * |
| * <h3>Methods Duplicated in Multiple Proxy Interfaces</h3> |
| * |
| * <p>When two or more interfaces of a proxy class contain a method with |
| * the same name and parameter signature, the order of the proxy class's |
| * interfaces becomes significant. When such a <i>duplicate method</i> |
| * is invoked on a proxy instance, the {@code Method} object passed |
| * to the invocation handler will not necessarily be the one whose |
| * declaring class is assignable from the reference type of the interface |
| * that the proxy's method was invoked through. This limitation exists |
| * because the corresponding method implementation in the generated proxy |
| * class cannot determine which interface it was invoked through. |
| * Therefore, when a duplicate method is invoked on a proxy instance, |
| * the {@code Method} object for the method in the foremost interface |
| * that contains the method (either directly or inherited through a |
| * superinterface) in the proxy class's list of interfaces is passed to |
| * the invocation handler's {@code invoke} method, regardless of the |
| * reference type through which the method invocation occurred. |
| * |
| * <p>If a proxy interface contains a method with the same name and |
| * parameter signature as the {@code hashCode}, {@code equals}, |
| * or {@code toString} methods of {@code java.lang.Object}, |
| * when such a method is invoked on a proxy instance, the |
| * {@code Method} object passed to the invocation handler will have |
| * {@code java.lang.Object} as its declaring class. In other words, |
| * the public, non-final methods of {@code java.lang.Object} |
| * logically precede all of the proxy interfaces for the determination of |
| * which {@code Method} object to pass to the invocation handler. |
| * |
| * <p>Note also that when a duplicate method is dispatched to an |
| * invocation handler, the {@code invoke} method may only throw |
| * checked exception types that are assignable to one of the exception |
| * types in the {@code throws} clause of the method in <i>all</i> of |
| * the proxy interfaces that it can be invoked through. If the |
| * {@code invoke} method throws a checked exception that is not |
| * assignable to any of the exception types declared by the method in one |
| * of the proxy interfaces that it can be invoked through, then an |
| * unchecked {@code UndeclaredThrowableException} will be thrown by |
| * the invocation on the proxy instance. This restriction means that not |
| * all of the exception types returned by invoking |
| * {@code getExceptionTypes} on the {@code Method} object |
| * passed to the {@code invoke} method can necessarily be thrown |
| * successfully by the {@code invoke} method. |
| * |
| * @author Peter Jones |
| * @see InvocationHandler |
| * @since 1.3 |
| */ |
| public class Proxy implements java.io.Serializable { |
| |
| private static final long serialVersionUID = -2222568056686623797L; |
| |
| /** prefix for all proxy class names */ |
| private final static String proxyClassNamePrefix = "$Proxy"; |
| |
| /** parameter types of a proxy class constructor */ |
| private final static Class[] constructorParams = |
| { InvocationHandler.class }; |
| |
| /** maps a class loader to the proxy class cache for that loader */ |
| private static Map<ClassLoader, Map<List<String>, Object>> loaderToCache |
| = new WeakHashMap<>(); |
| |
| /** marks that a particular proxy class is currently being generated */ |
| private static Object pendingGenerationMarker = new Object(); |
| |
| /** next number to use for generation of unique proxy class names */ |
| private static long nextUniqueNumber = 0; |
| private static Object nextUniqueNumberLock = new Object(); |
| |
| /** set of all generated proxy classes, for isProxyClass implementation */ |
| private static Map<Class<?>, Void> proxyClasses = |
| Collections.synchronizedMap(new WeakHashMap<Class<?>, Void>()); |
| |
| /** |
| * the invocation handler for this proxy instance. |
| * @serial |
| */ |
| protected InvocationHandler h; |
| |
| /** |
| * Prohibits instantiation. |
| */ |
| private Proxy() { |
| } |
| |
| /** |
| * Constructs a new {@code Proxy} instance from a subclass |
| * (typically, a dynamic proxy class) with the specified value |
| * for its invocation handler. |
| * |
| * @param h the invocation handler for this proxy instance |
| */ |
| protected Proxy(InvocationHandler h) { |
| doNewInstanceCheck(); |
| this.h = h; |
| } |
| |
| private static class ProxyAccessHelper { |
| // The permission is implementation specific. |
| static final Permission PROXY_PERMISSION = |
| new ReflectPermission("proxyConstructorNewInstance"); |
| // These system properties are defined to provide a short-term |
| // workaround if customers need to disable the new security checks. |
| static final boolean allowNewInstance; |
| static final boolean allowNullLoader; |
| static { |
| allowNewInstance = getBooleanProperty("sun.reflect.proxy.allowsNewInstance"); |
| allowNullLoader = getBooleanProperty("sun.reflect.proxy.allowsNullLoader"); |
| } |
| |
| private static boolean getBooleanProperty(final String key) { |
| String s = AccessController.doPrivileged(new PrivilegedAction<String>() { |
| public String run() { |
| return System.getProperty(key); |
| } |
| }); |
| return Boolean.valueOf(s); |
| } |
| |
| static boolean needsNewInstanceCheck(Class<?> proxyClass) { |
| if (!Proxy.isProxyClass(proxyClass) || allowNewInstance) { |
| return false; |
| } |
| |
| if (ReflectUtil.isNonPublicProxyClass(proxyClass)) { |
| for (Class<?> intf : proxyClass.getInterfaces()) { |
| if (!Modifier.isPublic(intf.getModifiers())) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| } |
| |
| /* |
| * Access check on a proxy class that implements any non-public interface. |
| * |
| * @throws SecurityException if a security manager exists, and |
| * the caller does not have the permission. |
| */ |
| private void doNewInstanceCheck() { |
| SecurityManager sm = System.getSecurityManager(); |
| Class<?> proxyClass = this.getClass(); |
| if (sm != null && ProxyAccessHelper.needsNewInstanceCheck(proxyClass)) { |
| try { |
| sm.checkPermission(ProxyAccessHelper.PROXY_PERMISSION); |
| } catch (SecurityException e) { |
| throw new SecurityException("Not allowed to construct a Proxy " |
| + "instance that implements a non-public interface", e); |
| } |
| } |
| } |
| |
| /** |
| * Returns the {@code java.lang.Class} object for a proxy class |
| * given a class loader and an array of interfaces. The proxy class |
| * will be defined by the specified class loader and will implement |
| * all of the supplied interfaces. If a proxy class for the same |
| * permutation of interfaces has already been defined by the class |
| * loader, then the existing proxy class will be returned; otherwise, |
| * a proxy class for those interfaces will be generated dynamically |
| * and defined by the class loader. |
| * |
| * <p>There are several restrictions on the parameters that may be |
| * passed to {@code Proxy.getProxyClass}: |
| * |
| * <ul> |
| * <li>All of the {@code Class} objects in the |
| * {@code interfaces} array must represent interfaces, not |
| * classes or primitive types. |
| * |
| * <li>No two elements in the {@code interfaces} array may |
| * refer to identical {@code Class} objects. |
| * |
| * <li>All of the interface types must be visible by name through the |
| * specified class loader. In other words, for class loader |
| * {@code cl} and every interface {@code i}, the following |
| * expression must be true: |
| * <pre> |
| * Class.forName(i.getName(), false, cl) == i |
| * </pre> |
| * |
| * <li>All non-public interfaces must be in the same package; |
| * otherwise, it would not be possible for the proxy class to |
| * implement all of the interfaces, regardless of what package it is |
| * defined in. |
| * |
| * <li>For any set of member methods of the specified interfaces |
| * that have the same signature: |
| * <ul> |
| * <li>If the return type of any of the methods is a primitive |
| * type or void, then all of the methods must have that same |
| * return type. |
| * <li>Otherwise, one of the methods must have a return type that |
| * is assignable to all of the return types of the rest of the |
| * methods. |
| * </ul> |
| * |
| * <li>The resulting proxy class must not exceed any limits imposed |
| * on classes by the virtual machine. For example, the VM may limit |
| * the number of interfaces that a class may implement to 65535; in |
| * that case, the size of the {@code interfaces} array must not |
| * exceed 65535. |
| * </ul> |
| * |
| * <p>If any of these restrictions are violated, |
| * {@code Proxy.getProxyClass} will throw an |
| * {@code IllegalArgumentException}. If the {@code interfaces} |
| * array argument or any of its elements are {@code null}, a |
| * {@code NullPointerException} will be thrown. |
| * |
| * <p>Note that the order of the specified proxy interfaces is |
| * significant: two requests for a proxy class with the same combination |
| * of interfaces but in a different order will result in two distinct |
| * proxy classes. |
| * |
| * @param loader the class loader to define the proxy class |
| * @param interfaces the list of interfaces for the proxy class |
| * to implement |
| * @return a proxy class that is defined in the specified class loader |
| * and that implements the specified interfaces |
| * @throws IllegalArgumentException if any of the restrictions on the |
| * parameters that may be passed to {@code getProxyClass} |
| * are violated |
| * @throws NullPointerException if the {@code interfaces} array |
| * argument or any of its elements are {@code null} |
| */ |
| @CallerSensitive |
| public static Class<?> getProxyClass(ClassLoader loader, |
| Class<?>... interfaces) |
| throws IllegalArgumentException |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| checkProxyAccess(Reflection.getCallerClass(), loader, interfaces); |
| } |
| |
| return getProxyClass0(loader, interfaces); |
| } |
| |
| /* |
| * Check permissions required to create a Proxy class. |
| * |
| * To define a proxy class, it performs the access checks as in |
| * Class.forName (VM will invoke ClassLoader.checkPackageAccess): |
| * 1. "getClassLoader" permission check if loader == null |
| * 2. checkPackageAccess on the interfaces it implements |
| * |
| * To get a constructor and new instance of a proxy class, it performs |
| * the package access check on the interfaces it implements |
| * as in Class.getConstructor. |
| * |
| * If an interface is non-public, the proxy class must be defined by |
| * the defining loader of the interface. If the caller's class loader |
| * is not the same as the defining loader of the interface, the VM |
| * will throw IllegalAccessError when the generated proxy class is |
| * being defined via the defineClass0 method. |
| */ |
| private static void checkProxyAccess(Class<?> caller, |
| ClassLoader loader, |
| Class<?>... interfaces) |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| ClassLoader ccl = caller.getClassLoader(); |
| if (loader == null && ccl != null) { |
| if (!ProxyAccessHelper.allowNullLoader) { |
| sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); |
| } |
| } |
| ReflectUtil.checkProxyPackageAccess(ccl, interfaces); |
| } |
| } |
| |
| /** |
| * Generate a proxy class. Must call the checkProxyAccess method |
| * to perform permission checks before calling this. |
| */ |
| private static Class<?> getProxyClass0(ClassLoader loader, |
| Class<?>... interfaces) { |
| if (interfaces.length > 65535) { |
| throw new IllegalArgumentException("interface limit exceeded"); |
| } |
| |
| Class<?> proxyClass = null; |
| |
| /* collect interface names to use as key for proxy class cache */ |
| String[] interfaceNames = new String[interfaces.length]; |
| |
| // for detecting duplicates |
| Set<Class<?>> interfaceSet = new HashSet<>(); |
| |
| for (int i = 0; i < interfaces.length; i++) { |
| /* |
| * Verify that the class loader resolves the name of this |
| * interface to the same Class object. |
| */ |
| String interfaceName = interfaces[i].getName(); |
| Class<?> interfaceClass = null; |
| try { |
| interfaceClass = Class.forName(interfaceName, false, loader); |
| } catch (ClassNotFoundException e) { |
| } |
| if (interfaceClass != interfaces[i]) { |
| throw new IllegalArgumentException( |
| interfaces[i] + " is not visible from class loader"); |
| } |
| |
| /* |
| * Verify that the Class object actually represents an |
| * interface. |
| */ |
| if (!interfaceClass.isInterface()) { |
| throw new IllegalArgumentException( |
| interfaceClass.getName() + " is not an interface"); |
| } |
| |
| /* |
| * Verify that this interface is not a duplicate. |
| */ |
| if (interfaceSet.contains(interfaceClass)) { |
| throw new IllegalArgumentException( |
| "repeated interface: " + interfaceClass.getName()); |
| } |
| interfaceSet.add(interfaceClass); |
| |
| interfaceNames[i] = interfaceName; |
| } |
| |
| /* |
| * Using string representations of the proxy interfaces as |
| * keys in the proxy class cache (instead of their Class |
| * objects) is sufficient because we require the proxy |
| * interfaces to be resolvable by name through the supplied |
| * class loader, and it has the advantage that using a string |
| * representation of a class makes for an implicit weak |
| * reference to the class. |
| */ |
| List<String> key = Arrays.asList(interfaceNames); |
| |
| /* |
| * Find or create the proxy class cache for the class loader. |
| */ |
| Map<List<String>, Object> cache; |
| synchronized (loaderToCache) { |
| cache = loaderToCache.get(loader); |
| if (cache == null) { |
| cache = new HashMap<>(); |
| loaderToCache.put(loader, cache); |
| } |
| /* |
| * This mapping will remain valid for the duration of this |
| * method, without further synchronization, because the mapping |
| * will only be removed if the class loader becomes unreachable. |
| */ |
| } |
| |
| /* |
| * Look up the list of interfaces in the proxy class cache using |
| * the key. This lookup will result in one of three possible |
| * kinds of values: |
| * null, if there is currently no proxy class for the list of |
| * interfaces in the class loader, |
| * the pendingGenerationMarker object, if a proxy class for the |
| * list of interfaces is currently being generated, |
| * or a weak reference to a Class object, if a proxy class for |
| * the list of interfaces has already been generated. |
| */ |
| synchronized (cache) { |
| /* |
| * Note that we need not worry about reaping the cache for |
| * entries with cleared weak references because if a proxy class |
| * has been garbage collected, its class loader will have been |
| * garbage collected as well, so the entire cache will be reaped |
| * from the loaderToCache map. |
| */ |
| do { |
| Object value = cache.get(key); |
| if (value instanceof Reference) { |
| proxyClass = (Class<?>) ((Reference) value).get(); |
| } |
| if (proxyClass != null) { |
| // proxy class already generated: return it |
| return proxyClass; |
| } else if (value == pendingGenerationMarker) { |
| // proxy class being generated: wait for it |
| try { |
| cache.wait(); |
| } catch (InterruptedException e) { |
| /* |
| * The class generation that we are waiting for should |
| * take a small, bounded time, so we can safely ignore |
| * thread interrupts here. |
| */ |
| } |
| continue; |
| } else { |
| /* |
| * No proxy class for this list of interfaces has been |
| * generated or is being generated, so we will go and |
| * generate it now. Mark it as pending generation. |
| */ |
| cache.put(key, pendingGenerationMarker); |
| break; |
| } |
| } while (true); |
| } |
| |
| try { |
| String proxyPkg = null; // package to define proxy class in |
| |
| /* |
| * Record the package of a non-public proxy interface so that the |
| * proxy class will be defined in the same package. Verify that |
| * all non-public proxy interfaces are in the same package. |
| */ |
| for (int i = 0; i < interfaces.length; i++) { |
| int flags = interfaces[i].getModifiers(); |
| if (!Modifier.isPublic(flags)) { |
| String name = interfaces[i].getName(); |
| int n = name.lastIndexOf('.'); |
| String pkg = ((n == -1) ? "" : name.substring(0, n + 1)); |
| if (proxyPkg == null) { |
| proxyPkg = pkg; |
| } else if (!pkg.equals(proxyPkg)) { |
| throw new IllegalArgumentException( |
| "non-public interfaces from different packages"); |
| } |
| } |
| } |
| |
| if (proxyPkg == null) { |
| // if no non-public proxy interfaces, use com.sun.proxy package |
| proxyPkg = ReflectUtil.PROXY_PACKAGE + "."; |
| } |
| |
| { |
| /* |
| * Choose a name for the proxy class to generate. |
| */ |
| long num; |
| synchronized (nextUniqueNumberLock) { |
| num = nextUniqueNumber++; |
| } |
| String proxyName = proxyPkg + proxyClassNamePrefix + num; |
| /* |
| * Verify that the class loader hasn't already |
| * defined a class with the chosen name. |
| */ |
| |
| /* |
| * Generate the specified proxy class. |
| */ |
| byte[] proxyClassFile = ProxyGenerator.generateProxyClass( |
| proxyName, interfaces); |
| try { |
| proxyClass = defineClass0(loader, proxyName, |
| proxyClassFile, 0, proxyClassFile.length); |
| } catch (ClassFormatError e) { |
| /* |
| * A ClassFormatError here means that (barring bugs in the |
| * proxy class generation code) there was some other |
| * invalid aspect of the arguments supplied to the proxy |
| * class creation (such as virtual machine limitations |
| * exceeded). |
| */ |
| throw new IllegalArgumentException(e.toString()); |
| } |
| } |
| // add to set of all generated proxy classes, for isProxyClass |
| proxyClasses.put(proxyClass, null); |
| |
| } finally { |
| /* |
| * We must clean up the "pending generation" state of the proxy |
| * class cache entry somehow. If a proxy class was successfully |
| * generated, store it in the cache (with a weak reference); |
| * otherwise, remove the reserved entry. In all cases, notify |
| * all waiters on reserved entries in this cache. |
| */ |
| synchronized (cache) { |
| if (proxyClass != null) { |
| cache.put(key, new WeakReference<Class<?>>(proxyClass)); |
| } else { |
| cache.remove(key); |
| } |
| cache.notifyAll(); |
| } |
| } |
| return proxyClass; |
| } |
| |
| /** |
| * Returns an instance of a proxy class for the specified interfaces |
| * that dispatches method invocations to the specified invocation |
| * handler. This method is equivalent to: |
| * <pre> |
| * Proxy.getProxyClass(loader, interfaces). |
| * getConstructor(new Class[] { InvocationHandler.class }). |
| * newInstance(new Object[] { handler }); |
| * </pre> |
| * |
| * <p>{@code Proxy.newProxyInstance} throws |
| * {@code IllegalArgumentException} for the same reasons that |
| * {@code Proxy.getProxyClass} does. |
| * |
| * @param loader the class loader to define the proxy class |
| * @param interfaces the list of interfaces for the proxy class |
| * to implement |
| * @param h the invocation handler to dispatch method invocations to |
| * @return a proxy instance with the specified invocation handler of a |
| * proxy class that is defined by the specified class loader |
| * and that implements the specified interfaces |
| * @throws IllegalArgumentException if any of the restrictions on the |
| * parameters that may be passed to {@code getProxyClass} |
| * are violated |
| * @throws NullPointerException if the {@code interfaces} array |
| * argument or any of its elements are {@code null}, or |
| * if the invocation handler, {@code h}, is |
| * {@code null} |
| */ |
| @CallerSensitive |
| public static Object newProxyInstance(ClassLoader loader, |
| Class<?>[] interfaces, |
| InvocationHandler h) |
| throws IllegalArgumentException |
| { |
| if (h == null) { |
| throw new NullPointerException(); |
| } |
| |
| final SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| checkProxyAccess(Reflection.getCallerClass(), loader, interfaces); |
| } |
| |
| /* |
| * Look up or generate the designated proxy class. |
| */ |
| Class<?> cl = getProxyClass0(loader, interfaces); |
| |
| /* |
| * Invoke its constructor with the designated invocation handler. |
| */ |
| try { |
| final Constructor<?> cons = cl.getConstructor(constructorParams); |
| final InvocationHandler ih = h; |
| if (sm != null && ProxyAccessHelper.needsNewInstanceCheck(cl)) { |
| // create proxy instance with doPrivilege as the proxy class may |
| // implement non-public interfaces that requires a special permission |
| return AccessController.doPrivileged(new PrivilegedAction<Object>() { |
| public Object run() { |
| return newInstance(cons, ih); |
| } |
| }); |
| } else { |
| return newInstance(cons, ih); |
| } |
| } catch (NoSuchMethodException e) { |
| throw new InternalError(e.toString()); |
| } |
| } |
| |
| private static Object newInstance(Constructor<?> cons, InvocationHandler h) { |
| try { |
| return cons.newInstance(new Object[] {h} ); |
| } catch (IllegalAccessException | InstantiationException e) { |
| throw new InternalError(e.toString()); |
| } catch (InvocationTargetException e) { |
| Throwable t = e.getCause(); |
| if (t instanceof RuntimeException) { |
| throw (RuntimeException) t; |
| } else { |
| throw new InternalError(t.toString()); |
| } |
| } |
| } |
| |
| /** |
| * Returns true if and only if the specified class was dynamically |
| * generated to be a proxy class using the {@code getProxyClass} |
| * method or the {@code newProxyInstance} method. |
| * |
| * <p>The reliability of this method is important for the ability |
| * to use it to make security decisions, so its implementation should |
| * not just test if the class in question extends {@code Proxy}. |
| * |
| * @param cl the class to test |
| * @return {@code true} if the class is a proxy class and |
| * {@code false} otherwise |
| * @throws NullPointerException if {@code cl} is {@code null} |
| */ |
| public static boolean isProxyClass(Class<?> cl) { |
| if (cl == null) { |
| throw new NullPointerException(); |
| } |
| |
| return proxyClasses.containsKey(cl); |
| } |
| |
| /** |
| * Returns the invocation handler for the specified proxy instance. |
| * |
| * @param proxy the proxy instance to return the invocation handler for |
| * @return the invocation handler for the proxy instance |
| * @throws IllegalArgumentException if the argument is not a |
| * proxy instance |
| */ |
| public static InvocationHandler getInvocationHandler(Object proxy) |
| throws IllegalArgumentException |
| { |
| /* |
| * Verify that the object is actually a proxy instance. |
| */ |
| if (!isProxyClass(proxy.getClass())) { |
| throw new IllegalArgumentException("not a proxy instance"); |
| } |
| |
| Proxy p = (Proxy) proxy; |
| return p.h; |
| } |
| |
| private static native Class defineClass0(ClassLoader loader, String name, |
| byte[] b, int off, int len); |
| } |
