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1390 lines
60 KiB
Java
1390 lines
60 KiB
Java
/*
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* Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.lang.reflect;
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import java.lang.invoke.MethodHandle;
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import java.lang.invoke.MethodHandles;
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import java.lang.invoke.MethodType;
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import java.lang.invoke.WrongMethodTypeException;
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import java.lang.module.ModuleDescriptor;
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import java.security.AccessController;
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import java.security.PrivilegedAction;
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import java.util.ArrayDeque;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.Deque;
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import java.util.HashMap;
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import java.util.HashSet;
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import java.util.IdentityHashMap;
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import java.util.List;
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import java.util.Map;
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import java.util.Objects;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.concurrent.atomic.AtomicInteger;
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import java.util.concurrent.atomic.AtomicLong;
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import java.util.function.BooleanSupplier;
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import jdk.internal.access.JavaLangAccess;
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import jdk.internal.access.SharedSecrets;
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import jdk.internal.module.Modules;
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import jdk.internal.misc.VM;
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import jdk.internal.reflect.CallerSensitive;
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import jdk.internal.reflect.Reflection;
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import jdk.internal.loader.ClassLoaderValue;
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import jdk.internal.vm.annotation.Stable;
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import sun.reflect.misc.ReflectUtil;
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import sun.security.action.GetPropertyAction;
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import sun.security.util.SecurityConstants;
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import static java.lang.invoke.MethodType.methodType;
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import static java.lang.module.ModuleDescriptor.Modifier.SYNTHETIC;
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/**
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*
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* {@code Proxy} provides static methods for creating objects that act like instances
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* of interfaces but allow for customized method invocation.
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* To create a proxy instance for some interface {@code Foo}:
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* <pre>{@code
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* InvocationHandler handler = new MyInvocationHandler(...);
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* Foo f = (Foo) Proxy.newProxyInstance(Foo.class.getClassLoader(),
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* new Class<?>[] { Foo.class },
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* handler);
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* }</pre>
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*
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* <p>
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* A <em>proxy class</em> is a class created at runtime that implements a specified
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* list of interfaces, known as <em>proxy interfaces</em>. A <em>proxy instance</em>
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* is an instance of a proxy class.
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*
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* Each proxy instance has an associated <i>invocation handler</i>
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* object, which implements the interface {@link InvocationHandler}.
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* A method invocation on a proxy instance through one of its proxy
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* interfaces will be dispatched to the {@link InvocationHandler#invoke
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* invoke} method of the instance's invocation handler, passing the proxy
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* instance, a {@code java.lang.reflect.Method} object identifying
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* the method that was invoked, and an array of type {@code Object}
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* containing the arguments. The invocation handler processes the
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* encoded method invocation as appropriate and the result that it
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* returns will be returned as the result of the method invocation on
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* the proxy instance.
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*
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* <p>A proxy class has the following properties:
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*
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* <ul>
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* <li>The unqualified name of a proxy class is unspecified. The space
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* of class names that begin with the string {@code "$Proxy"}
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* should be, however, reserved for proxy classes.
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*
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* <li>The package and module in which a proxy class is defined is specified
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* <a href="#membership">below</a>.
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*
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* <li>A proxy class is <em>final and non-abstract</em>.
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*
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* <li>A proxy class extends {@code java.lang.reflect.Proxy}.
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*
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* <li>A proxy class implements exactly the interfaces specified at its
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* creation, in the same order. Invoking {@link Class#getInterfaces() getInterfaces}
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* on its {@code Class} object will return an array containing the same
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* list of interfaces (in the order specified at its creation), invoking
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* {@link Class#getMethods getMethods} on its {@code Class} object will return
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* an array of {@code Method} objects that include all of the
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* methods in those interfaces, and invoking {@code getMethod} will
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* find methods in the proxy interfaces as would be expected.
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*
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* <li>The {@link java.security.ProtectionDomain} of a proxy class
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* is the same as that of system classes loaded by the bootstrap class
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* loader, such as {@code java.lang.Object}, because the code for a
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* proxy class is generated by trusted system code. This protection
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* domain will typically be granted {@code java.security.AllPermission}.
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*
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* <li>The {@link Proxy#isProxyClass Proxy.isProxyClass} method can be used
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* to determine if a given class is a proxy class.
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* </ul>
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*
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* <p>A proxy instance has the following properties:
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*
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* <ul>
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* <li>Given a proxy instance {@code proxy} and one of the
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* interfaces, {@code Foo}, implemented by its proxy class, the
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* following expression will return true:
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* <pre>
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* {@code proxy instanceof Foo}
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* </pre>
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* and the following cast operation will succeed (rather than throwing
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* a {@code ClassCastException}):
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* <pre>
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* {@code (Foo) proxy}
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* </pre>
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*
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* <li>Each proxy instance has an associated invocation handler, the one
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* that was passed to its constructor. The static
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* {@link Proxy#getInvocationHandler Proxy.getInvocationHandler} method
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* will return the invocation handler associated with the proxy instance
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* passed as its argument.
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*
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* <li>An interface method invocation on a proxy instance will be
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* encoded and dispatched to the invocation handler's {@link
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* InvocationHandler#invoke invoke} method as described in the
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* documentation for that method.
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*
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* <li>A proxy interface may define a default method or inherit
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* a default method from its superinterface directly or indirectly.
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* An invocation handler can invoke a default method of a proxy interface
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* by calling {@link InvocationHandler#invokeDefault(Object, Method, Object...)
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* InvocationHandler::invokeDefault}.
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*
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* <li>An invocation of the {@code hashCode},
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* {@code equals}, or {@code toString} methods declared in
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* {@code java.lang.Object} on a proxy instance will be encoded and
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* dispatched to the invocation handler's {@code invoke} method in
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* the same manner as interface method invocations are encoded and
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* dispatched, as described above. The declaring class of the
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* {@code Method} object passed to {@code invoke} will be
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* {@code java.lang.Object}. Other public methods of a proxy
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* instance inherited from {@code java.lang.Object} are not
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* overridden by a proxy class, so invocations of those methods behave
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* like they do for instances of {@code java.lang.Object}.
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* </ul>
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*
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* <h2><a id="membership">Package and Module Membership of Proxy Class</a></h2>
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*
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* The package and module to which a proxy class belongs are chosen such that
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* the accessibility of the proxy class is in line with the accessibility of
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* the proxy interfaces. Specifically, the package and the module membership
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* of a proxy class defined via the
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* {@link Proxy#getProxyClass(ClassLoader, Class[])} or
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* {@link Proxy#newProxyInstance(ClassLoader, Class[], InvocationHandler)}
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* methods is specified as follows:
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*
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* <ol>
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* <li>If all the proxy interfaces are in <em>exported</em> or <em>open</em>
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* packages:
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* <ol type="a">
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* <li>if all the proxy interfaces are <em>public</em>, then the proxy class is
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* <em>public</em> in an unconditionally exported but non-open package.
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* The name of the package and the module are unspecified.</li>
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*
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* <li>if at least one of all the proxy interfaces is <em>non-public</em>, then
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* the proxy class is <em>non-public</em> in the package and module of the
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* non-public interfaces. All the non-public interfaces must be in the same
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* package and module; otherwise, proxying them is
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* <a href="#restrictions">not possible</a>.</li>
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* </ol>
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* </li>
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* <li>If at least one proxy interface is in a package that is
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* <em>non-exported</em> and <em>non-open</em>:
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* <ol type="a">
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* <li>if all the proxy interfaces are <em>public</em>, then the proxy class is
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* <em>public</em> in a <em>non-exported</em>, <em>non-open</em> package of
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* <a href="#dynamicmodule"><em>dynamic module</em>.</a>
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* The names of the package and the module are unspecified.</li>
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*
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* <li>if at least one of all the proxy interfaces is <em>non-public</em>, then
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* the proxy class is <em>non-public</em> in the package and module of the
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* non-public interfaces. All the non-public interfaces must be in the same
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* package and module; otherwise, proxying them is
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* <a href="#restrictions">not possible</a>.</li>
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* </ol>
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* </li>
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* </ol>
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*
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* <p>
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* Note that if proxy interfaces with a mix of accessibilities -- for example,
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* an exported public interface and a non-exported non-public interface -- are
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* proxied by the same instance, then the proxy class's accessibility is
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* governed by the least accessible proxy interface.
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* <p>
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* Note that it is possible for arbitrary code to obtain access to a proxy class
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* in an open package with {@link AccessibleObject#setAccessible setAccessible},
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* whereas a proxy class in a non-open package is never accessible to
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* code outside the module of the proxy class.
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*
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* <p>
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* Throughout this specification, a "non-exported package" refers to a package
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* that is not exported to all modules, and a "non-open package" refers to
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* a package that is not open to all modules. Specifically, these terms refer to
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* a package that either is not exported/open by its containing module or is
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* exported/open in a qualified fashion by its containing module.
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*
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* <h3><a id="dynamicmodule">Dynamic Modules</a></h3>
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* <p>
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* A dynamic module is a named module generated at runtime. A proxy class
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* defined in a dynamic module is encapsulated and not accessible to any module.
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* Calling {@link Constructor#newInstance(Object...)} on a proxy class in
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* a dynamic module will throw {@code IllegalAccessException};
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* {@code Proxy.newProxyInstance} method should be used instead.
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*
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* <p>
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* A dynamic module can read the modules of all of the superinterfaces of a proxy
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* class and the modules of the classes and interfaces referenced by
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* all public method signatures of a proxy class. If a superinterface or
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* a referenced class or interface, say {@code T}, is in a non-exported package,
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* the {@linkplain Module module} of {@code T} is updated to export the
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* package of {@code T} to the dynamic module.
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*
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* <h3>Methods Duplicated in Multiple Proxy Interfaces</h3>
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*
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* <p>When two or more proxy interfaces contain a method with
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* the same name and parameter signature, the order of the proxy class's
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* interfaces becomes significant. When such a <i>duplicate method</i>
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* is invoked on a proxy instance, the {@code Method} object passed
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* to the invocation handler will not necessarily be the one whose
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* declaring class is assignable from the reference type of the interface
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* that the proxy's method was invoked through. This limitation exists
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* because the corresponding method implementation in the generated proxy
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* class cannot determine which interface it was invoked through.
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* Therefore, when a duplicate method is invoked on a proxy instance,
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* the {@code Method} object for the method in the foremost interface
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* that contains the method (either directly or inherited through a
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* superinterface) in the proxy class's list of interfaces is passed to
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* the invocation handler's {@code invoke} method, regardless of the
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* reference type through which the method invocation occurred.
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*
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* <p>If a proxy interface contains a method with the same name and
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* parameter signature as the {@code hashCode}, {@code equals},
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* or {@code toString} methods of {@code java.lang.Object},
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* when such a method is invoked on a proxy instance, the
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* {@code Method} object passed to the invocation handler will have
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* {@code java.lang.Object} as its declaring class. In other words,
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* the public, non-final methods of {@code java.lang.Object}
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* logically precede all of the proxy interfaces for the determination of
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* which {@code Method} object to pass to the invocation handler.
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*
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* <p>Note also that when a duplicate method is dispatched to an
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* invocation handler, the {@code invoke} method may only throw
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* checked exception types that are assignable to one of the exception
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* types in the {@code throws} clause of the method in <i>all</i> of
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* the proxy interfaces that it can be invoked through. If the
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* {@code invoke} method throws a checked exception that is not
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* assignable to any of the exception types declared by the method in one
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* of the proxy interfaces that it can be invoked through, then an
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* unchecked {@code UndeclaredThrowableException} will be thrown by
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* the invocation on the proxy instance. This restriction means that not
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* all of the exception types returned by invoking
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* {@code getExceptionTypes} on the {@code Method} object
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* passed to the {@code invoke} method can necessarily be thrown
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* successfully by the {@code invoke} method.
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*
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* @author Peter Jones
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* @see InvocationHandler
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* @since 1.3
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*/
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public class Proxy implements java.io.Serializable {
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@java.io.Serial
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private static final long serialVersionUID = -2222568056686623797L;
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/** parameter types of a proxy class constructor */
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private static final Class<?>[] constructorParams =
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{ InvocationHandler.class };
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/**
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* a cache of proxy constructors with
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* {@link Constructor#setAccessible(boolean) accessible} flag already set
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*/
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private static final ClassLoaderValue<Constructor<?>> proxyCache =
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new ClassLoaderValue<>();
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/**
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* the invocation handler for this proxy instance.
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* @serial
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*/
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@SuppressWarnings("serial") // Not statically typed as Serializable
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protected InvocationHandler h;
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/**
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* Prohibits instantiation.
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*/
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private Proxy() {
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}
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/**
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* Constructs a new {@code Proxy} instance from a subclass
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* (typically, a dynamic proxy class) with the specified value
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* for its invocation handler.
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*
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* @param h the invocation handler for this proxy instance
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*
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* @throws NullPointerException if the given invocation handler, {@code h},
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* is {@code null}.
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*/
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protected Proxy(InvocationHandler h) {
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Objects.requireNonNull(h);
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this.h = h;
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}
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/**
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* Returns the {@code java.lang.Class} object for a proxy class
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* given a class loader and an array of interfaces. The proxy class
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* will be defined by the specified class loader and will implement
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* all of the supplied interfaces. If any of the given interfaces
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* is non-public, the proxy class will be non-public. If a proxy class
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* for the same permutation of interfaces has already been defined by the
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* class loader, then the existing proxy class will be returned; otherwise,
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* a proxy class for those interfaces will be generated dynamically
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* and defined by the class loader.
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*
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* @param loader the class loader to define the proxy class
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* @param interfaces the list of interfaces for the proxy class
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* to implement
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* @return a proxy class that is defined in the specified class loader
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* and that implements the specified interfaces
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* @throws IllegalArgumentException if any of the <a href="#restrictions">
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* restrictions</a> on the parameters are violated
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* @throws SecurityException if a security manager, <em>s</em>, is present
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* and any of the following conditions is met:
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* <ul>
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* <li> the given {@code loader} is {@code null} and
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* the caller's class loader is not {@code null} and the
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* invocation of {@link SecurityManager#checkPermission
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* s.checkPermission} with
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* {@code RuntimePermission("getClassLoader")} permission
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* denies access.</li>
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* <li> for each proxy interface, {@code intf},
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* the caller's class loader is not the same as or an
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* ancestor of the class loader for {@code intf} and
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* invocation of {@link SecurityManager#checkPackageAccess
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* s.checkPackageAccess()} denies access to {@code intf}.</li>
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* </ul>
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* @throws NullPointerException if the {@code interfaces} array
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* argument or any of its elements are {@code null}
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*
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* @deprecated Proxy classes generated in a named module are encapsulated
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* and not accessible to code outside its module.
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* {@link Constructor#newInstance(Object...) Constructor.newInstance}
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* will throw {@code IllegalAccessException} when it is called on
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* an inaccessible proxy class.
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* Use {@link #newProxyInstance(ClassLoader, Class[], InvocationHandler)}
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* to create a proxy instance instead.
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*
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* @see <a href="#membership">Package and Module Membership of Proxy Class</a>
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*/
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@Deprecated
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@CallerSensitive
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public static Class<?> getProxyClass(ClassLoader loader,
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Class<?>... interfaces)
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throws IllegalArgumentException
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{
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@SuppressWarnings("removal")
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Class<?> caller = System.getSecurityManager() == null
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? null
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: Reflection.getCallerClass();
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return getProxyConstructor(caller, loader, interfaces)
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.getDeclaringClass();
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}
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/**
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* Returns the {@code Constructor} object of a proxy class that takes a
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* single argument of type {@link InvocationHandler}, given a class loader
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* and an array of interfaces. The returned constructor will have the
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* {@link Constructor#setAccessible(boolean) accessible} flag already set.
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*
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* @param caller passed from a public-facing @CallerSensitive method if
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* SecurityManager is set or {@code null} if there's no
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* SecurityManager
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* @param loader the class loader to define the proxy class
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* @param interfaces the list of interfaces for the proxy class
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* to implement
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* @return a Constructor of the proxy class taking single
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* {@code InvocationHandler} parameter
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*/
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private static Constructor<?> getProxyConstructor(Class<?> caller,
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ClassLoader loader,
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Class<?>... interfaces)
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{
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// optimization for single interface
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if (interfaces.length == 1) {
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Class<?> intf = interfaces[0];
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if (caller != null) {
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checkProxyAccess(caller, loader, intf);
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}
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return proxyCache.sub(intf).computeIfAbsent(
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loader,
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(ld, clv) -> new ProxyBuilder(ld, clv.key()).build()
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);
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} else {
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// interfaces cloned
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final Class<?>[] intfsArray = interfaces.clone();
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if (caller != null) {
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checkProxyAccess(caller, loader, intfsArray);
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}
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final List<Class<?>> intfs = Arrays.asList(intfsArray);
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return proxyCache.sub(intfs).computeIfAbsent(
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loader,
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(ld, clv) -> new ProxyBuilder(ld, clv.key()).build()
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);
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}
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}
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/*
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* Check permissions required to create a Proxy class.
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*
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* To define a proxy class, it performs the access checks as in
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* Class.forName (VM will invoke ClassLoader.checkPackageAccess):
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* 1. "getClassLoader" permission check if loader == null
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* 2. checkPackageAccess on the interfaces it implements
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*
|
|
* 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)
|
|
{
|
|
@SuppressWarnings("removal")
|
|
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 JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
|
|
|
|
// 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 record ProxyClassContext(Module module, String packageName, int accessFlags) {
|
|
private ProxyClassContext {
|
|
if (module.isNamed()) {
|
|
if (packageName.isEmpty()) {
|
|
// Per JLS 7.4.2, unnamed package can only exist in unnamed modules.
|
|
// This means a package-private superinterface exist in the unnamed
|
|
// package of a named module.
|
|
throw new InternalError("Unnamed package cannot be added to " + module);
|
|
}
|
|
|
|
if (!module.getDescriptor().packages().contains(packageName)) {
|
|
throw new InternalError(packageName + " not exist in " + module.getName());
|
|
}
|
|
|
|
if (!module.isOpen(packageName, Proxy.class.getModule())) {
|
|
// Required for default method invocation
|
|
throw new InternalError(packageName + " not open to " + Proxy.class.getModule());
|
|
}
|
|
} else {
|
|
if (Modifier.isPublic(accessFlags)) {
|
|
// All proxy superinterfaces are public, must be in named dynamic module
|
|
throw new InternalError("public proxy in unnamed module: " + module);
|
|
}
|
|
}
|
|
|
|
if ((accessFlags & ~Modifier.PUBLIC) != 0) {
|
|
throw new InternalError("proxy access flags must be Modifier.PUBLIC or 0");
|
|
}
|
|
}
|
|
}
|
|
|
|
private static Class<?> defineProxyClass(ProxyClassContext context, List<Class<?>> interfaces) {
|
|
/*
|
|
* Choose a name for the proxy class to generate.
|
|
*/
|
|
long num = nextUniqueNumber.getAndIncrement();
|
|
String proxyName = context.packageName().isEmpty()
|
|
? proxyClassNamePrefix + num
|
|
: context.packageName() + "." + proxyClassNamePrefix + num;
|
|
|
|
ClassLoader loader = getLoader(context.module());
|
|
trace(proxyName, context.module(), loader, interfaces);
|
|
|
|
/*
|
|
* Generate the specified proxy class.
|
|
*/
|
|
byte[] proxyClassFile = ProxyGenerator.generateProxyClass(loader, proxyName, interfaces,
|
|
context.accessFlags() | Modifier.FINAL);
|
|
try {
|
|
Class<?> pc = JLA.defineClass(loader, proxyName, proxyClassFile,
|
|
null, "__dynamic_proxy__");
|
|
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(ProxyClassContext, 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.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 ProxyClassContext context;
|
|
ProxyBuilder(ClassLoader loader, List<Class<?>> interfaces) {
|
|
Objects.requireNonNull(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.context = proxyClassContext(loader, interfaces, refTypes);
|
|
assert getLoader(context.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.
|
|
*/
|
|
@SuppressWarnings("removal")
|
|
Constructor<?> build() {
|
|
Class<?> proxyClass = defineProxyClass(context, 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 object actually represents an
|
|
* interface.
|
|
*/
|
|
if (!intf.isInterface()) {
|
|
throw new IllegalArgumentException(intf.getName() + " is not an interface");
|
|
}
|
|
|
|
if (intf.isHidden()) {
|
|
throw new IllegalArgumentException(intf.getName() + " is a hidden interface");
|
|
}
|
|
|
|
if (intf.isSealed()) {
|
|
throw new IllegalArgumentException(intf.getName() + " is a sealed interface");
|
|
}
|
|
|
|
/*
|
|
* Verify that the class loader resolves the name of this
|
|
* interface to the same Class object.
|
|
*/
|
|
ensureVisible(loader, intf);
|
|
|
|
/*
|
|
* 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) {
|
|
var types = new HashSet<Class<?>>();
|
|
for (var intf : interfaces) {
|
|
for (Method m : intf.getMethods()) {
|
|
if (!Modifier.isStatic(m.getModifiers())) {
|
|
addElementType(types, m.getReturnType());
|
|
addElementTypes(types, m.getSharedParameterTypes());
|
|
addElementTypes(types, m.getSharedExceptionTypes());
|
|
}
|
|
}
|
|
}
|
|
return types;
|
|
}
|
|
|
|
private static void addElementTypes(HashSet<Class<?>> types,
|
|
Class<?> ... classes) {
|
|
for (var cls : classes) {
|
|
addElementType(types, cls);
|
|
}
|
|
}
|
|
|
|
private static void addElementType(HashSet<Class<?>> types,
|
|
Class<?> cls) {
|
|
var type = getElementType(cls);
|
|
if (!type.isPrimitive()) {
|
|
types.add(type);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the context for the generated proxy class, including the
|
|
* module and the package it belongs to and whether it is package-private.
|
|
*
|
|
* If any of proxy interface is package-private, then the proxy class
|
|
* is in the same package and module as the package-private interface.
|
|
*
|
|
* If all proxy interfaces are public and in exported packages,
|
|
* then the proxy class is in a dynamic module in an unconditionally
|
|
* exported package.
|
|
*
|
|
* 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.
|
|
*
|
|
* The package of proxy class is open to java.base for deep reflective access.
|
|
*
|
|
* Reads edge and qualified exports are added for dynamic module to access.
|
|
*/
|
|
private static ProxyClassContext proxyClassContext(ClassLoader loader,
|
|
List<Class<?>> interfaces,
|
|
Set<Class<?>> refTypes) {
|
|
Map<Class<?>, Module> packagePrivateTypes = new HashMap<>();
|
|
boolean nonExported = false;
|
|
|
|
for (Class<?> intf : interfaces) {
|
|
Module m = intf.getModule();
|
|
if (!Modifier.isPublic(intf.getModifiers())) {
|
|
packagePrivateTypes.put(intf, m);
|
|
} else {
|
|
if (!intf.getModule().isExported(intf.getPackageName())) {
|
|
// module-private types
|
|
nonExported = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
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)
|
|
Module targetModule = null;
|
|
String targetPackageName = null;
|
|
for (Map.Entry<Class<?>, Module> e : packagePrivateTypes.entrySet()) {
|
|
Class<?> intf = e.getKey();
|
|
Module m = e.getValue();
|
|
if ((targetModule != null && targetModule != m) ||
|
|
(targetPackageName != null && targetPackageName != intf.getPackageName())) {
|
|
throw new IllegalArgumentException(
|
|
"cannot have non-public interfaces in different packages");
|
|
}
|
|
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");
|
|
}
|
|
|
|
targetModule = m;
|
|
targetPackageName = e.getKey().getPackageName();
|
|
}
|
|
|
|
// validate if the target module can access all other interfaces
|
|
for (Class<?> intf : interfaces) {
|
|
Module m = intf.getModule();
|
|
if (m == targetModule) continue;
|
|
|
|
if (!targetModule.canRead(m) || !m.isExported(intf.getPackageName(), targetModule)) {
|
|
throw new IllegalArgumentException(targetModule + " can't access " + intf.getName());
|
|
}
|
|
}
|
|
|
|
// opens the package of the non-public proxy class for java.base to access
|
|
if (targetModule.isNamed()) {
|
|
Modules.addOpens(targetModule, targetPackageName, Proxy.class.getModule());
|
|
}
|
|
// return the module of the package-private interface
|
|
return new ProxyClassContext(targetModule, targetPackageName, 0);
|
|
}
|
|
|
|
// All proxy interfaces are public. So maps to a dynamic proxy module
|
|
// and add reads edge and qualified exports, if necessary
|
|
Module targetModule = 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(targetModule, c);
|
|
}
|
|
|
|
var pkgName = nonExported ? PROXY_PACKAGE_PREFIX + '.' + targetModule.getName()
|
|
: targetModule.getName();
|
|
return new ProxyClassContext(targetModule, pkgName, Modifier.PUBLIC);
|
|
}
|
|
|
|
/*
|
|
* 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: " + JLA.getLoaderNameID(ld));
|
|
}
|
|
}
|
|
|
|
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 with a package named $MODULE which
|
|
* is unconditionally exported and another package named
|
|
* com.sun.proxy.$MODULE which is encapsulated.
|
|
*
|
|
* 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, mn))
|
|
.exports(mn)
|
|
.build();
|
|
Module m = Modules.defineModule(ld, descriptor, null);
|
|
Modules.addReads(m, Proxy.class.getModule());
|
|
Modules.addExports(m, mn);
|
|
// java.base to create proxy instance and access its Lookup instance
|
|
Modules.addOpens(m, pn, Proxy.class.getModule());
|
|
Modules.addOpens(m, mn, Proxy.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 {@linkplain Class#isHidden() non-hidden} and
|
|
* {@linkplain Class#isSealed() non-sealed} 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>
|
|
*/
|
|
@CallerSensitive
|
|
public static Object newProxyInstance(ClassLoader loader,
|
|
Class<?>[] interfaces,
|
|
InvocationHandler h) {
|
|
Objects.requireNonNull(h);
|
|
|
|
@SuppressWarnings("removal")
|
|
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 re) {
|
|
throw re;
|
|
} else {
|
|
throw new InternalError(t.toString(), t);
|
|
}
|
|
}
|
|
}
|
|
|
|
private static void checkNewProxyPermission(Class<?> caller, Class<?> proxyClass) {
|
|
@SuppressWarnings("removal")
|
|
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
|
|
String pkg = proxyClass.getPackageName();
|
|
String callerPkg = caller.getPackageName();
|
|
|
|
if (pcl != ccl || !pkg.equals(callerPkg)) {
|
|
sm.checkPermission(new ReflectPermission("newProxyInPackage." + pkg));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the class loader for the given module.
|
|
*/
|
|
@SuppressWarnings("removal")
|
|
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}
|
|
*/
|
|
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.
|
|
*/
|
|
@SuppressWarnings("removal")
|
|
@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 String PROXY_PACKAGE_PREFIX = ReflectUtil.PROXY_PACKAGE;
|
|
|
|
/**
|
|
* A cache of Method -> MethodHandle for default methods.
|
|
*/
|
|
private static final ClassValue<ConcurrentHashMap<Method, MethodHandle>>
|
|
DEFAULT_METHODS_MAP = new ClassValue<>() {
|
|
@Override
|
|
protected ConcurrentHashMap<Method, MethodHandle> computeValue(Class<?> type) {
|
|
return new ConcurrentHashMap<>(4);
|
|
}
|
|
};
|
|
|
|
private static ConcurrentHashMap<Method, MethodHandle> defaultMethodMap(Class<?> proxyClass) {
|
|
assert isProxyClass(proxyClass);
|
|
return DEFAULT_METHODS_MAP.get(proxyClass);
|
|
}
|
|
|
|
static final Object[] EMPTY_ARGS = new Object[0];
|
|
|
|
static MethodHandle defaultMethodHandle(Class<? extends Proxy> proxyClass, Method method) {
|
|
// lookup the cached method handle
|
|
ConcurrentHashMap<Method, MethodHandle> methods = defaultMethodMap(proxyClass);
|
|
MethodHandle superMH = methods.get(method);
|
|
if (superMH == null) {
|
|
MethodType type = methodType(method.getReturnType(), method.getParameterTypes());
|
|
MethodHandles.Lookup lookup = MethodHandles.lookup();
|
|
Class<?> proxyInterface = findProxyInterfaceOrElseThrow(proxyClass, method);
|
|
MethodHandle dmh;
|
|
try {
|
|
dmh = proxyClassLookup(lookup, proxyClass)
|
|
.findSpecial(proxyInterface, method.getName(), type, proxyClass)
|
|
.withVarargs(false);
|
|
} catch (IllegalAccessException | NoSuchMethodException e) {
|
|
// should not reach here
|
|
throw new InternalError(e);
|
|
}
|
|
// this check can be turned into assertion as it is guaranteed to succeed by the virtue of
|
|
// looking up a default (instance) method declared or inherited by proxyInterface
|
|
// while proxyClass implements (is a subtype of) proxyInterface ...
|
|
assert ((BooleanSupplier) () -> {
|
|
try {
|
|
// make sure that the method type matches
|
|
dmh.asType(type.insertParameterTypes(0, proxyClass));
|
|
return true;
|
|
} catch (WrongMethodTypeException e) {
|
|
return false;
|
|
}
|
|
}).getAsBoolean() : "Wrong method type";
|
|
// change return type to Object
|
|
MethodHandle mh = dmh.asType(dmh.type().changeReturnType(Object.class));
|
|
// wrap any exception thrown with InvocationTargetException
|
|
mh = MethodHandles.catchException(mh, Throwable.class, InvocationException.wrapMH());
|
|
// spread array of arguments among parameters (skipping 1st parameter - target)
|
|
mh = mh.asSpreader(1, Object[].class, type.parameterCount());
|
|
// change target type to Object
|
|
mh = mh.asType(MethodType.methodType(Object.class, Object.class, Object[].class));
|
|
|
|
// push MH into cache
|
|
MethodHandle cached = methods.putIfAbsent(method, mh);
|
|
if (cached != null) {
|
|
superMH = cached;
|
|
} else {
|
|
superMH = mh;
|
|
}
|
|
}
|
|
return superMH;
|
|
}
|
|
|
|
/**
|
|
* Finds the first proxy interface that declares the given method
|
|
* directly or indirectly.
|
|
*
|
|
* @throws IllegalArgumentException if not found
|
|
*/
|
|
private static Class<?> findProxyInterfaceOrElseThrow(Class<?> proxyClass, Method method) {
|
|
Class<?> declaringClass = method.getDeclaringClass();
|
|
if (!declaringClass.isInterface()) {
|
|
throw new IllegalArgumentException("\"" + method +
|
|
"\" is not a method declared in the proxy class");
|
|
}
|
|
|
|
List<Class<?>> proxyInterfaces = Arrays.asList(proxyClass.getInterfaces());
|
|
// the method's declaring class is a proxy interface
|
|
if (proxyInterfaces.contains(declaringClass))
|
|
return declaringClass;
|
|
|
|
// find the first proxy interface that inherits the default method
|
|
// i.e. the declaring class of the default method is a superinterface
|
|
// of the proxy interface
|
|
Deque<Class<?>> deque = new ArrayDeque<>();
|
|
Set<Class<?>> visited = new HashSet<>();
|
|
boolean indirectMethodRef = false;
|
|
for (Class<?> proxyIntf : proxyInterfaces) {
|
|
assert proxyIntf != declaringClass;
|
|
visited.add(proxyIntf);
|
|
deque.add(proxyIntf);
|
|
|
|
// for each proxy interface, traverse its subinterfaces with
|
|
// breadth-first search to find a subinterface declaring the
|
|
// default method
|
|
Class<?> c;
|
|
while ((c = deque.poll()) != null) {
|
|
if (c == declaringClass) {
|
|
try {
|
|
// check if this method is the resolved method if referenced from
|
|
// this proxy interface (i.e. this method is not implemented
|
|
// by any other superinterface)
|
|
Method m = proxyIntf.getMethod(method.getName(), method.getSharedParameterTypes());
|
|
if (m.getDeclaringClass() == declaringClass) {
|
|
return proxyIntf;
|
|
}
|
|
indirectMethodRef = true;
|
|
} catch (NoSuchMethodException e) {}
|
|
|
|
// skip traversing its superinterfaces
|
|
// another proxy interface may extend it and so
|
|
// the method's declaring class is left unvisited.
|
|
continue;
|
|
}
|
|
// visit all superinterfaces of one proxy interface to find if
|
|
// this proxy interface inherits the method directly or indirectly
|
|
visited.add(c);
|
|
for (Class<?> superIntf : c.getInterfaces()) {
|
|
if (!visited.contains(superIntf) && !deque.contains(superIntf)) {
|
|
if (superIntf == declaringClass) {
|
|
// fast-path as the matching subinterface is found
|
|
deque.addFirst(superIntf);
|
|
} else {
|
|
deque.add(superIntf);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
throw new IllegalArgumentException("\"" + method + (indirectMethodRef
|
|
? "\" is overridden directly or indirectly by the proxy interfaces"
|
|
: "\" is not a method declared in the proxy class"));
|
|
}
|
|
|
|
/**
|
|
* This method invokes the proxy's proxyClassLookup method to get a
|
|
* Lookup on the proxy class.
|
|
*
|
|
* @return a lookup for proxy class of this proxy instance
|
|
*/
|
|
@SuppressWarnings("removal")
|
|
private static MethodHandles.Lookup proxyClassLookup(MethodHandles.Lookup caller, Class<?> proxyClass) {
|
|
return AccessController.doPrivileged(new PrivilegedAction<>() {
|
|
@Override
|
|
public MethodHandles.Lookup run() {
|
|
try {
|
|
Method m = proxyClass.getDeclaredMethod("proxyClassLookup", MethodHandles.Lookup.class);
|
|
m.setAccessible(true);
|
|
return (MethodHandles.Lookup) m.invoke(null, caller);
|
|
} catch (ReflectiveOperationException e) {
|
|
throw new InternalError(e);
|
|
}
|
|
}
|
|
});
|
|
}
|
|
|
|
/*
|
|
* Invoke the default method of the given proxy with an explicit caller class.
|
|
*
|
|
* @throws IllegalAccessException if the proxy interface is inaccessible to the caller
|
|
* if caller is non-null
|
|
*/
|
|
static Object invokeDefault(Object proxy, Method method, Object[] args, Class<?> caller)
|
|
throws Throwable {
|
|
// verify that the object is actually a proxy instance
|
|
if (!Proxy.isProxyClass(proxy.getClass())) {
|
|
throw new IllegalArgumentException("'proxy' is not a proxy instance");
|
|
}
|
|
if (!method.isDefault()) {
|
|
throw new IllegalArgumentException("\"" + method + "\" is not a default method");
|
|
}
|
|
@SuppressWarnings("unchecked")
|
|
Class<? extends Proxy> proxyClass = (Class<? extends Proxy>)proxy.getClass();
|
|
|
|
// skip access check if caller is null
|
|
if (caller != null) {
|
|
Class<?> intf = method.getDeclaringClass();
|
|
// access check on the default method
|
|
method.checkAccess(caller, intf, proxyClass, method.getModifiers());
|
|
}
|
|
|
|
MethodHandle mh = Proxy.defaultMethodHandle(proxyClass, method);
|
|
// invoke the super method
|
|
try {
|
|
// the args array can be null if the number of formal parameters required by
|
|
// the method is zero (consistent with Method::invoke)
|
|
Object[] params = args != null ? args : Proxy.EMPTY_ARGS;
|
|
return mh.invokeExact(proxy, params);
|
|
} catch (ClassCastException | NullPointerException e) {
|
|
throw new IllegalArgumentException(e.getMessage(), e);
|
|
} catch (Proxy.InvocationException e) {
|
|
// unwrap and throw the exception thrown by the default method
|
|
throw e.getCause();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Internal exception type to wrap the exception thrown by the default method
|
|
* so that it can distinguish CCE and NPE thrown due to the arguments
|
|
* incompatible with the method signature.
|
|
*/
|
|
static class InvocationException extends ReflectiveOperationException {
|
|
@java.io.Serial
|
|
private static final long serialVersionUID = 0L;
|
|
|
|
InvocationException(Throwable cause) {
|
|
super(cause);
|
|
}
|
|
|
|
/**
|
|
* Wraps given cause with InvocationException and throws it.
|
|
*/
|
|
static Object wrap(Throwable cause) throws InvocationException {
|
|
throw new InvocationException(cause);
|
|
}
|
|
|
|
@Stable
|
|
static MethodHandle wrapMethodHandle;
|
|
|
|
static MethodHandle wrapMH() {
|
|
MethodHandle mh = wrapMethodHandle;
|
|
if (mh == null) {
|
|
try {
|
|
wrapMethodHandle = mh = MethodHandles.lookup().findStatic(
|
|
InvocationException.class,
|
|
"wrap",
|
|
MethodType.methodType(Object.class, Throwable.class)
|
|
);
|
|
} catch (NoSuchMethodException | IllegalAccessException e) {
|
|
throw new InternalError(e);
|
|
}
|
|
}
|
|
return mh;
|
|
}
|
|
}
|
|
|
|
}
|