--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/reflect/Proxy.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1119 @@
+/*
+ * Copyright (c) 1999, 2017, 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.module.ModuleDescriptor;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import jdk.internal.loader.BootLoader;
+import jdk.internal.module.Modules;
+import jdk.internal.misc.Unsafe;
+import jdk.internal.misc.VM;
+import jdk.internal.reflect.CallerSensitive;
+import jdk.internal.reflect.Reflection;
+import jdk.internal.loader.ClassLoaderValue;
+import sun.reflect.misc.ReflectUtil;
+import sun.security.action.GetPropertyAction;
+import sun.security.util.SecurityConstants;
+
+import static java.lang.module.ModuleDescriptor.Modifier.SYNTHETIC;
+
+
+/**
+ *
+ * {@code Proxy} provides static methods for creating objects that act like instances
+ * of interfaces but allow for customized method invocation.
+ * To create a proxy instance for some interface {@code Foo}:
+ * <pre>{@code
+ * InvocationHandler handler = new MyInvocationHandler(...);
+ * Foo f = (Foo) Proxy.newProxyInstance(Foo.class.getClassLoader(),
+ * new Class<?>[] { Foo.class },
+ * handler);
+ * }</pre>
+ *
+ * <p>
+ * A <em>proxy class</em> is a class created at runtime that implements a specified
+ * list of interfaces, known as <em>proxy interfaces</em>. A <em>proxy instance</em>
+ * 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>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>The package and module in which a proxy class is defined is specified
+ * <a href="#membership">below</a>.
+ *
+ * <li>A proxy class is <em>final and non-abstract</em>.
+ *
+ * <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. Invoking {@link Class#getInterfaces getInterfaces}
+ * on its {@code Class} object will return an array containing the same
+ * list of interfaces (in the order specified at its creation), invoking
+ * {@link Class#getMethods 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 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>The {@link Proxy#isProxyClass Proxy.isProxyClass} method can be used
+ * to determine if a given class is a proxy class.
+ * </ul>
+ *
+ * <p>A proxy instance has the following properties:
+ *
+ * <ul>
+ * <li>Given a proxy instance {@code proxy} and one of the
+ * interfaces, {@code Foo}, implemented by its proxy class, 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><a id="membership">Package and Module Membership of Proxy Class</a></h3>
+ *
+ * The package and module to which a proxy class belongs are chosen such that
+ * the accessibility of the proxy class is in line with the accessibility of
+ * the proxy interfaces. Specifically, the package and the module membership
+ * of a proxy class defined via the
+ * {@link Proxy#getProxyClass(ClassLoader, Class[])} or
+ * {@link Proxy#newProxyInstance(ClassLoader, Class[], InvocationHandler)}
+ * methods is specified as follows:
+ *
+ * <ol>
+ * <li>If all the proxy interfaces are in <em>exported</em> or <em>open</em>
+ * packages:
+ * <ol type="a">
+ * <li>if all the proxy interfaces are <em>public</em>, then the proxy class is
+ * <em>public</em> in a package exported by the
+ * {@linkplain ClassLoader#getUnnamedModule() unnamed module} of the specified
+ * loader. The name of the package is unspecified.</li>
+ *
+ * <li>if at least one of all the proxy interfaces is <em>non-public</em>, then
+ * the proxy class is <em>non-public</em> in the package and module of the
+ * non-public interfaces. All the non-public interfaces must be in the same
+ * package and module; otherwise, proxying them is
+ * <a href="#restrictions">not possible</a>.</li>
+ * </ol>
+ * </li>
+ * <li>If at least one proxy interface is in a package that is
+ * <em>non-exported</em> and <em>non-open</em>:
+ * <ol type="a">
+ * <li>if all the proxy interfaces are <em>public</em>, then the proxy class is
+ * <em>public</em> in a <em>non-exported</em>, <em>non-open</em> package of
+ * <a href="#dynamicmodule"><em>dynamic module</em>.</a>
+ * The names of the package and the module are unspecified.</li>
+ *
+ * <li>if at least one of all the proxy interfaces is <em>non-public</em>, then
+ * the proxy class is <em>non-public</em> in the package and module of the
+ * non-public interfaces. All the non-public interfaces must be in the same
+ * package and module; otherwise, proxying them is
+ * <a href="#restrictions">not possible</a>.</li>
+ * </ol>
+ * </li>
+ * </ol>
+ *
+ * <p>
+ * Note that if proxy interfaces with a mix of accessibilities -- for example,
+ * an exported public interface and a non-exported non-public interface -- are
+ * proxied by the same instance, then the proxy class's accessibility is
+ * governed by the least accessible proxy interface.
+ * <p>
+ * Note that it is possible for arbitrary code to obtain access to a proxy class
+ * in an open package with {@link AccessibleObject#setAccessible setAccessible},
+ * whereas a proxy class in a non-open package is never accessible to
+ * code outside the module of the proxy class.
+ *
+ * <p>
+ * Throughout this specification, a "non-exported package" refers to a package
+ * that is not exported to all modules, and a "non-open package" refers to
+ * a package that is not open to all modules. Specifically, these terms refer to
+ * a package that either is not exported/open by its containing module or is
+ * exported/open in a qualified fashion by its containing module.
+ *
+ * <h3><a id="dynamicmodule">Dynamic Modules</a></h3>
+ * <p>
+ * A dynamic module is a named module generated at runtime. A proxy class
+ * defined in a dynamic module is encapsulated and not accessible to any module.
+ * Calling {@link Constructor#newInstance(Object...)} on a proxy class in
+ * a dynamic module will throw {@code IllegalAccessException};
+ * {@code Proxy.newProxyInstance} method should be used instead.
+ *
+ * <p>
+ * A dynamic module can read the modules of all of the superinterfaces of a proxy
+ * class and the modules of the types referenced by all public method signatures
+ * of a proxy class. If a superinterface or a referenced type, say {@code T},
+ * is in a non-exported package, the {@linkplain Module module} of {@code T} is
+ * updated to export the package of {@code T} to the dynamic module.
+ *
+ * <h3>Methods Duplicated in Multiple Proxy Interfaces</h3>
+ *
+ * <p>When two or more proxy interfaces 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
+ * @revised 9
+ * @spec JPMS
+ */
+public class Proxy implements java.io.Serializable {
+ private static final long serialVersionUID = -2222568056686623797L;
+
+ /** parameter types of a proxy class constructor */
+ private static final Class<?>[] constructorParams =
+ { InvocationHandler.class };
+
+ /**
+ * a cache of proxy constructors with
+ * {@link Constructor#setAccessible(boolean) accessible} flag already set
+ */
+ private static final ClassLoaderValue<Constructor<?>> proxyCache =
+ new ClassLoaderValue<>();
+
+ /**
+ * 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
+ *
+ * @throws NullPointerException if the given invocation handler, {@code h},
+ * is {@code null}.
+ */
+ protected Proxy(InvocationHandler h) {
+ Objects.requireNonNull(h);
+ this.h = h;
+ }
+
+ /**
+ * 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 any of the given interfaces
+ * is non-public, the proxy class will be non-public. 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.
+ *
+ * @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 <a href="#restrictions">
+ * restrictions</a> on the parameters are violated
+ * @throws SecurityException if a security manager, <em>s</em>, is present
+ * and any of the following conditions is met:
+ * <ul>
+ * <li> the given {@code loader} is {@code null} and
+ * the caller's class loader is not {@code null} and the
+ * invocation of {@link SecurityManager#checkPermission
+ * s.checkPermission} with
+ * {@code RuntimePermission("getClassLoader")} permission
+ * denies access.</li>
+ * <li> for each proxy interface, {@code intf},
+ * the caller's class loader is not the same as or an
+ * ancestor of the class loader for {@code intf} and
+ * invocation of {@link SecurityManager#checkPackageAccess
+ * s.checkPackageAccess()} denies access to {@code intf}.</li>
+ * </ul>
+ * @throws NullPointerException if the {@code interfaces} array
+ * argument or any of its elements are {@code null}
+ *
+ * @deprecated Proxy classes generated in a named module are encapsulated
+ * and not accessible to code outside its module.
+ * {@link Constructor#newInstance(Object...) Constructor.newInstance}
+ * will throw {@code IllegalAccessException} when it is called on
+ * an inaccessible proxy class.
+ * Use {@link #newProxyInstance(ClassLoader, Class[], InvocationHandler)}
+ * to create a proxy instance instead.
+ *
+ * @see <a href="#membership">Package and Module Membership of Proxy Class</a>
+ * @revised 9
+ * @spec JPMS
+ */
+ @Deprecated
+ @CallerSensitive
+ public static Class<?> getProxyClass(ClassLoader loader,
+ Class<?>... interfaces)
+ throws IllegalArgumentException
+ {
+ Class<?> caller = System.getSecurityManager() == null
+ ? null
+ : Reflection.getCallerClass();
+
+ return getProxyConstructor(caller, loader, interfaces)
+ .getDeclaringClass();
+ }
+
+ /**
+ * Returns the {@code Constructor} object of a proxy class that takes a
+ * single argument of type {@link InvocationHandler}, given a class loader
+ * and an array of interfaces. The returned constructor will have the
+ * {@link Constructor#setAccessible(boolean) accessible} flag already set.
+ *
+ * @param caller passed from a public-facing @CallerSensitive method if
+ * SecurityManager is set or {@code null} if there's no
+ * SecurityManager
+ * @param loader the class loader to define the proxy class
+ * @param interfaces the list of interfaces for the proxy class
+ * to implement
+ * @return a Constructor of the proxy class taking single
+ * {@code InvocationHandler} parameter
+ */
+ private static Constructor<?> getProxyConstructor(Class<?> caller,
+ ClassLoader loader,
+ Class<?>... interfaces)
+ {
+ // optimization for single interface
+ if (interfaces.length == 1) {
+ Class<?> intf = interfaces[0];
+ if (caller != null) {
+ checkProxyAccess(caller, loader, intf);
+ }
+ return proxyCache.sub(intf).computeIfAbsent(
+ loader,
+ (ld, clv) -> new ProxyBuilder(ld, clv.key()).build()
+ );
+ } else {
+ // interfaces cloned
+ final Class<?>[] intfsArray = interfaces.clone();
+ if (caller != null) {
+ checkProxyAccess(caller, loader, intfsArray);
+ }
+ final List<Class<?>> intfs = Arrays.asList(intfsArray);
+ return proxyCache.sub(intfs).computeIfAbsent(
+ loader,
+ (ld, clv) -> new ProxyBuilder(ld, clv.key()).build()
+ );
+ }
+ }
+
+ /*
+ * 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.
+ */
+ 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) {
+ sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
+ }
+ ReflectUtil.checkProxyPackageAccess(ccl, interfaces);
+ }
+ }
+
+ /**
+ * Builder for a proxy class.
+ *
+ * If the module is not specified in this ProxyBuilder constructor,
+ * it will map from the given loader and interfaces to the module
+ * in which the proxy class will be defined.
+ */
+ private static final class ProxyBuilder {
+ private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+
+ // prefix for all proxy class names
+ private static final String proxyClassNamePrefix = "$Proxy";
+
+ // next number to use for generation of unique proxy class names
+ private static final AtomicLong nextUniqueNumber = new AtomicLong();
+
+ // a reverse cache of defined proxy classes
+ private static final ClassLoaderValue<Boolean> reverseProxyCache =
+ new ClassLoaderValue<>();
+
+ private static Class<?> defineProxyClass(Module m, List<Class<?>> interfaces) {
+ String proxyPkg = null; // package to define proxy class in
+ int accessFlags = Modifier.PUBLIC | Modifier.FINAL;
+
+ /*
+ * 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 (Class<?> intf : interfaces) {
+ int flags = intf.getModifiers();
+ if (!Modifier.isPublic(flags)) {
+ accessFlags = Modifier.FINAL; // non-public, final
+ String pkg = intf.getPackageName();
+ if (proxyPkg == null) {
+ proxyPkg = pkg;
+ } else if (!pkg.equals(proxyPkg)) {
+ throw new IllegalArgumentException(
+ "non-public interfaces from different packages");
+ }
+ }
+ }
+
+ if (proxyPkg == null) {
+ // all proxy interfaces are public
+ proxyPkg = m.isNamed() ? PROXY_PACKAGE_PREFIX + "." + m.getName()
+ : PROXY_PACKAGE_PREFIX;
+ } else if (proxyPkg.isEmpty() && m.isNamed()) {
+ throw new IllegalArgumentException(
+ "Unnamed package cannot be added to " + m);
+ }
+
+ if (m.isNamed()) {
+ if (!m.getDescriptor().packages().contains(proxyPkg)) {
+ throw new InternalError(proxyPkg + " not exist in " + m.getName());
+ }
+ }
+
+ /*
+ * Choose a name for the proxy class to generate.
+ */
+ long num = nextUniqueNumber.getAndIncrement();
+ String proxyName = proxyPkg.isEmpty()
+ ? proxyClassNamePrefix + num
+ : proxyPkg + "." + proxyClassNamePrefix + num;
+
+ ClassLoader loader = getLoader(m);
+ trace(proxyName, m, loader, interfaces);
+
+ /*
+ * Generate the specified proxy class.
+ */
+ byte[] proxyClassFile = ProxyGenerator.generateProxyClass(
+ proxyName, interfaces.toArray(EMPTY_CLASS_ARRAY), accessFlags);
+ try {
+ Class<?> pc = UNSAFE.defineClass(proxyName, proxyClassFile,
+ 0, proxyClassFile.length,
+ loader, null);
+ reverseProxyCache.sub(pc).putIfAbsent(loader, Boolean.TRUE);
+ return pc;
+ } 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());
+ }
+ }
+
+ /**
+ * Test if given class is a class defined by
+ * {@link #defineProxyClass(Module, List)}
+ */
+ static boolean isProxyClass(Class<?> c) {
+ return Objects.equals(reverseProxyCache.sub(c).get(c.getClassLoader()),
+ Boolean.TRUE);
+ }
+
+ private static boolean isExportedType(Class<?> c) {
+ String pn = c.getPackageName();
+ return Modifier.isPublic(c.getModifiers()) && c.getModule().isExported(pn);
+ }
+
+ private static boolean isPackagePrivateType(Class<?> c) {
+ return !Modifier.isPublic(c.getModifiers());
+ }
+
+ private static String toDetails(Class<?> c) {
+ String access = "unknown";
+ if (isExportedType(c)) {
+ access = "exported";
+ } else if (isPackagePrivateType(c)) {
+ access = "package-private";
+ } else {
+ access = "module-private";
+ }
+ ClassLoader ld = c.getClassLoader();
+ return String.format(" %s/%s %s loader %s",
+ c.getModule().getName(), c.getName(), access, ld);
+ }
+
+ static void trace(String cn,
+ Module module,
+ ClassLoader loader,
+ List<Class<?>> interfaces) {
+ if (isDebug()) {
+ System.err.format("PROXY: %s/%s defined by %s%n",
+ module.getName(), cn, loader);
+ }
+ if (isDebug("debug")) {
+ interfaces.stream()
+ .forEach(c -> System.out.println(toDetails(c)));
+ }
+ }
+
+ private static final String DEBUG =
+ GetPropertyAction.privilegedGetProperty("jdk.proxy.debug", "");
+
+ private static boolean isDebug() {
+ return !DEBUG.isEmpty();
+ }
+ private static boolean isDebug(String flag) {
+ return DEBUG.equals(flag);
+ }
+
+ // ProxyBuilder instance members start here....
+
+ private final List<Class<?>> interfaces;
+ private final Module module;
+ ProxyBuilder(ClassLoader loader, List<Class<?>> interfaces) {
+ if (!VM.isModuleSystemInited()) {
+ throw new InternalError("Proxy is not supported until "
+ + "module system is fully initialized");
+ }
+ if (interfaces.size() > 65535) {
+ throw new IllegalArgumentException("interface limit exceeded: "
+ + interfaces.size());
+ }
+
+ Set<Class<?>> refTypes = referencedTypes(loader, interfaces);
+
+ // IAE if violates any restrictions specified in newProxyInstance
+ validateProxyInterfaces(loader, interfaces, refTypes);
+
+ this.interfaces = interfaces;
+ this.module = mapToModule(loader, interfaces, refTypes);
+ assert getLoader(module) == loader;
+ }
+
+ ProxyBuilder(ClassLoader loader, Class<?> intf) {
+ this(loader, Collections.singletonList(intf));
+ }
+
+ /**
+ * Generate a proxy class and return its proxy Constructor with
+ * accessible flag already set. If the target module does not have access
+ * to any interface types, IllegalAccessError will be thrown by the VM
+ * at defineClass time.
+ *
+ * Must call the checkProxyAccess method to perform permission checks
+ * before calling this.
+ */
+ Constructor<?> build() {
+ Class<?> proxyClass = defineProxyClass(module, interfaces);
+ final Constructor<?> cons;
+ try {
+ cons = proxyClass.getConstructor(constructorParams);
+ } catch (NoSuchMethodException e) {
+ throw new InternalError(e.toString(), e);
+ }
+ AccessController.doPrivileged(new PrivilegedAction<Void>() {
+ public Void run() {
+ cons.setAccessible(true);
+ return null;
+ }
+ });
+ return cons;
+ }
+
+ /**
+ * Validate the given proxy interfaces and the given referenced types
+ * are visible to the defining loader.
+ *
+ * @throws IllegalArgumentException if it violates the restrictions
+ * specified in {@link Proxy#newProxyInstance}
+ */
+ private static void validateProxyInterfaces(ClassLoader loader,
+ List<Class<?>> interfaces,
+ Set<Class<?>> refTypes)
+ {
+ Map<Class<?>, Boolean> interfaceSet = new IdentityHashMap<>(interfaces.size());
+ for (Class<?> intf : interfaces) {
+ /*
+ * Verify that the class loader resolves the name of this
+ * interface to the same Class object.
+ */
+ ensureVisible(loader, intf);
+
+ /*
+ * Verify that the Class object actually represents an
+ * interface.
+ */
+ if (!intf.isInterface()) {
+ throw new IllegalArgumentException(intf.getName() + " is not an interface");
+ }
+
+ /*
+ * Verify that this interface is not a duplicate.
+ */
+ if (interfaceSet.put(intf, Boolean.TRUE) != null) {
+ throw new IllegalArgumentException("repeated interface: " + intf.getName());
+ }
+ }
+
+ for (Class<?> type : refTypes) {
+ ensureVisible(loader, type);
+ }
+ }
+
+ /*
+ * Returns all types referenced by all public non-static method signatures of
+ * the proxy interfaces
+ */
+ private static Set<Class<?>> referencedTypes(ClassLoader loader,
+ List<Class<?>> interfaces) {
+ return interfaces.stream()
+ .flatMap(intf -> Stream.of(intf.getMethods())
+ .filter(m -> !Modifier.isStatic(m.getModifiers()))
+ .flatMap(ProxyBuilder::methodRefTypes)
+ .map(ProxyBuilder::getElementType)
+ .filter(t -> !t.isPrimitive()))
+ .collect(Collectors.toSet());
+ }
+
+ /*
+ * Extracts all types referenced on a method signature including
+ * its return type, parameter types, and exception types.
+ */
+ private static Stream<Class<?>> methodRefTypes(Method m) {
+ return Stream.of(new Class<?>[] { m.getReturnType() },
+ m.getParameterTypes(),
+ m.getExceptionTypes())
+ .flatMap(Stream::of);
+ }
+
+ /**
+ * Returns the module that the generated proxy class belongs to.
+ *
+ * If all proxy interfaces are public and in exported packages,
+ * then the proxy class is in unnamed module.
+ *
+ * If any of proxy interface is package-private, then the proxy class
+ * is in the same module of the package-private interface.
+ *
+ * If all proxy interfaces are public and at least one in a non-exported
+ * package, then the proxy class is in a dynamic module in a
+ * non-exported package. Reads edge and qualified exports are added
+ * for dynamic module to access.
+ */
+ private static Module mapToModule(ClassLoader loader,
+ List<Class<?>> interfaces,
+ Set<Class<?>> refTypes) {
+ Map<Class<?>, Module> modulePrivateTypes = new HashMap<>();
+ Map<Class<?>, Module> packagePrivateTypes = new HashMap<>();
+ for (Class<?> intf : interfaces) {
+ Module m = intf.getModule();
+ if (Modifier.isPublic(intf.getModifiers())) {
+ // module-private types
+ if (!m.isExported(intf.getPackageName())) {
+ modulePrivateTypes.put(intf, m);
+ }
+ } else {
+ packagePrivateTypes.put(intf, m);
+ }
+ }
+
+ // all proxy interfaces are public and exported, the proxy class
+ // is in unnamed module. Such proxy class is accessible to
+ // any unnamed module and named module that can read unnamed module
+ if (packagePrivateTypes.isEmpty() && modulePrivateTypes.isEmpty()) {
+ return loader != null ? loader.getUnnamedModule()
+ : BootLoader.getUnnamedModule();
+ }
+
+ if (packagePrivateTypes.size() > 0) {
+ // all package-private types must be in the same runtime package
+ // i.e. same package name and same module (named or unnamed)
+ //
+ // Configuration will fail if M1 and in M2 defined by the same loader
+ // and both have the same package p (so no need to check class loader)
+ if (packagePrivateTypes.size() > 1 &&
+ (packagePrivateTypes.keySet().stream() // more than one package
+ .map(Class::getPackageName).distinct().count() > 1 ||
+ packagePrivateTypes.values().stream() // or more than one module
+ .distinct().count() > 1)) {
+ throw new IllegalArgumentException(
+ "non-public interfaces from different packages");
+ }
+
+ // all package-private types are in the same module (named or unnamed)
+ Module target = null;
+ for (Module m : packagePrivateTypes.values()) {
+ if (getLoader(m) != loader) {
+ // the specified loader is not the same class loader
+ // of the non-public interface
+ throw new IllegalArgumentException(
+ "non-public interface is not defined by the given loader");
+ }
+ target = m;
+ }
+
+ // validate if the target module can access all other interfaces
+ for (Class<?> intf : interfaces) {
+ Module m = intf.getModule();
+ if (m == target) continue;
+
+ if (!target.canRead(m) || !m.isExported(intf.getPackageName(), target)) {
+ throw new IllegalArgumentException(target + " can't access " + intf.getName());
+ }
+ }
+
+ // return the module of the package-private interface
+ return target;
+ }
+
+ // All proxy interfaces are public and at least one in a non-exported
+ // package. So maps to a dynamic proxy module and add reads edge
+ // and qualified exports, if necessary
+ Module target = getDynamicModule(loader);
+
+ // set up proxy class access to proxy interfaces and types
+ // referenced in the method signature
+ Set<Class<?>> types = new HashSet<>(interfaces);
+ types.addAll(refTypes);
+ for (Class<?> c : types) {
+ ensureAccess(target, c);
+ }
+ return target;
+ }
+
+ /*
+ * Ensure the given module can access the given class.
+ */
+ private static void ensureAccess(Module target, Class<?> c) {
+ Module m = c.getModule();
+ // add read edge and qualified export for the target module to access
+ if (!target.canRead(m)) {
+ Modules.addReads(target, m);
+ }
+ String pn = c.getPackageName();
+ if (!m.isExported(pn, target)) {
+ Modules.addExports(m, pn, target);
+ }
+ }
+
+ /*
+ * Ensure the given class is visible to the class loader.
+ */
+ private static void ensureVisible(ClassLoader ld, Class<?> c) {
+ Class<?> type = null;
+ try {
+ type = Class.forName(c.getName(), false, ld);
+ } catch (ClassNotFoundException e) {
+ }
+ if (type != c) {
+ throw new IllegalArgumentException(c.getName() +
+ " referenced from a method is not visible from class loader");
+ }
+ }
+
+ private static Class<?> getElementType(Class<?> type) {
+ Class<?> e = type;
+ while (e.isArray()) {
+ e = e.getComponentType();
+ }
+ return e;
+ }
+
+ private static final ClassLoaderValue<Module> dynProxyModules =
+ new ClassLoaderValue<>();
+ private static final AtomicInteger counter = new AtomicInteger();
+
+ /*
+ * Define a dynamic module for the generated proxy classes in
+ * a non-exported package named com.sun.proxy.$MODULE.
+ *
+ * Each class loader will have one dynamic module.
+ */
+ private static Module getDynamicModule(ClassLoader loader) {
+ return dynProxyModules.computeIfAbsent(loader, (ld, clv) -> {
+ // create a dynamic module and setup module access
+ String mn = "jdk.proxy" + counter.incrementAndGet();
+ String pn = PROXY_PACKAGE_PREFIX + "." + mn;
+ ModuleDescriptor descriptor =
+ ModuleDescriptor.newModule(mn, Set.of(SYNTHETIC))
+ .packages(Set.of(pn))
+ .build();
+ Module m = Modules.defineModule(ld, descriptor, null);
+ Modules.addReads(m, Proxy.class.getModule());
+ // java.base to create proxy instance
+ Modules.addExports(m, pn, Object.class.getModule());
+ return m;
+ });
+ }
+ }
+
+ /**
+ * Returns a proxy instance for the specified interfaces
+ * that dispatches method invocations to the specified invocation
+ * handler.
+ * <p>
+ * <a id="restrictions">{@code IllegalArgumentException} will be thrown
+ * if any of the following restrictions is violated:</a>
+ * <ul>
+ * <li>All of {@code Class} objects in the given {@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:<p>
+ * {@code Class.forName(i.getName(), false, cl) == i}
+ *
+ * <li>All of the types referenced by all
+ * public method signatures of the specified interfaces
+ * and those inherited by their superinterfaces
+ * must be visible by name through the specified class loader.
+ *
+ * <li>All non-public interfaces must be in the same package
+ * and module, defined by the specified class loader and
+ * the module of the non-public interfaces can access all of
+ * the interface types; 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>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
+ * @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 <a href="#restrictions">
+ * restrictions</a> on the parameters are violated
+ * @throws SecurityException if a security manager, <em>s</em>, is present
+ * and any of the following conditions is met:
+ * <ul>
+ * <li> the given {@code loader} is {@code null} and
+ * the caller's class loader is not {@code null} and the
+ * invocation of {@link SecurityManager#checkPermission
+ * s.checkPermission} with
+ * {@code RuntimePermission("getClassLoader")} permission
+ * denies access;</li>
+ * <li> for each proxy interface, {@code intf},
+ * the caller's class loader is not the same as or an
+ * ancestor of the class loader for {@code intf} and
+ * invocation of {@link SecurityManager#checkPackageAccess
+ * s.checkPackageAccess()} denies access to {@code intf};</li>
+ * <li> any of the given proxy interfaces is non-public and the
+ * caller class is not in the same {@linkplain Package runtime package}
+ * as the non-public interface and the invocation of
+ * {@link SecurityManager#checkPermission s.checkPermission} with
+ * {@code ReflectPermission("newProxyInPackage.{package name}")}
+ * permission denies access.</li>
+ * </ul>
+ * @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}
+ *
+ * @see <a href="#membership">Package and Module Membership of Proxy Class</a>
+ * @revised 9
+ * @spec JPMS
+ */
+ @CallerSensitive
+ public static Object newProxyInstance(ClassLoader loader,
+ Class<?>[] interfaces,
+ InvocationHandler h) {
+ Objects.requireNonNull(h);
+
+ final Class<?> caller = System.getSecurityManager() == null
+ ? null
+ : Reflection.getCallerClass();
+
+ /*
+ * Look up or generate the designated proxy class and its constructor.
+ */
+ Constructor<?> cons = getProxyConstructor(caller, loader, interfaces);
+
+ return newProxyInstance(caller, cons, h);
+ }
+
+ private static Object newProxyInstance(Class<?> caller, // null if no SecurityManager
+ Constructor<?> cons,
+ InvocationHandler h) {
+ /*
+ * Invoke its constructor with the designated invocation handler.
+ */
+ try {
+ if (caller != null) {
+ checkNewProxyPermission(caller, cons.getDeclaringClass());
+ }
+
+ return cons.newInstance(new Object[]{h});
+ } catch (IllegalAccessException | InstantiationException e) {
+ throw new InternalError(e.toString(), e);
+ } catch (InvocationTargetException e) {
+ Throwable t = e.getCause();
+ if (t instanceof RuntimeException) {
+ throw (RuntimeException) t;
+ } else {
+ throw new InternalError(t.toString(), t);
+ }
+ }
+ }
+
+ private static void checkNewProxyPermission(Class<?> caller, Class<?> proxyClass) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ if (ReflectUtil.isNonPublicProxyClass(proxyClass)) {
+ ClassLoader ccl = caller.getClassLoader();
+ ClassLoader pcl = proxyClass.getClassLoader();
+
+ // do permission check if the caller is in a different runtime package
+ // of the proxy class
+ int n = proxyClass.getName().lastIndexOf('.');
+ String pkg = (n == -1) ? "" : proxyClass.getName().substring(0, n);
+
+ n = caller.getName().lastIndexOf('.');
+ String callerPkg = (n == -1) ? "" : caller.getName().substring(0, n);
+
+ if (pcl != ccl || !pkg.equals(callerPkg)) {
+ sm.checkPermission(new ReflectPermission("newProxyInPackage." + pkg));
+ }
+ }
+ }
+ }
+
+ /**
+ * Returns the class loader for the given module.
+ */
+ private static ClassLoader getLoader(Module m) {
+ PrivilegedAction<ClassLoader> pa = m::getClassLoader;
+ return AccessController.doPrivileged(pa);
+ }
+
+ /**
+ * Returns true if the given class is a proxy class.
+ *
+ * @implNote 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}
+ *
+ * @revised 9
+ * @spec JPMS
+ */
+ public static boolean isProxyClass(Class<?> cl) {
+ return Proxy.class.isAssignableFrom(cl) && ProxyBuilder.isProxyClass(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
+ * @throws SecurityException if a security manager, <em>s</em>, is present
+ * and the caller's class loader is not the same as or an
+ * ancestor of the class loader for the invocation handler
+ * and invocation of {@link SecurityManager#checkPackageAccess
+ * s.checkPackageAccess()} denies access to the invocation
+ * handler's class.
+ */
+ @CallerSensitive
+ 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");
+ }
+
+ final Proxy p = (Proxy) proxy;
+ final InvocationHandler ih = p.h;
+ if (System.getSecurityManager() != null) {
+ Class<?> ihClass = ih.getClass();
+ Class<?> caller = Reflection.getCallerClass();
+ if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(),
+ ihClass.getClassLoader()))
+ {
+ ReflectUtil.checkPackageAccess(ihClass);
+ }
+ }
+
+ return ih;
+ }
+
+ private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
+ private static final String PROXY_PACKAGE_PREFIX = ReflectUtil.PROXY_PACKAGE;
+}