/*

 * Copyright (c) 2001, 2018, 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 sun.reflect;

import java.io.OptionalDataException;

import java.lang.invoke.MethodHandle;

import java.lang.reflect.Constructor;

import java.lang.reflect.InvocationTargetException;

import java.security.AccessController;

import java.security.Permission;

import java.security.PrivilegedAction;

/**

 * ReflectionFactory supports custom serialization.

 * Its methods support the creation of uninitialized objects, invoking serialization

 * private methods for readObject, writeObject, readResolve, and writeReplace.

 * <p>

 * ReflectionFactory access is restricted, if a security manager is active,

 * unless the permission {@code RuntimePermission("reflectionFactoryAccess")}

 * is granted.

 */

public class ReflectionFactory {

    private static final ReflectionFactory soleInstance = new ReflectionFactory();

    private static final jdk.internal.reflect.ReflectionFactory delegate = AccessController.doPrivileged(

            new PrivilegedAction<jdk.internal.reflect.ReflectionFactory>() {

                public jdk.internal.reflect.ReflectionFactory run() {

                    return jdk.internal.reflect.ReflectionFactory.getReflectionFactory();

                }

            });

    private ReflectionFactory() {}

    private static final Permission REFLECTION_FACTORY_ACCESS_PERM

            = new RuntimePermission("reflectionFactoryAccess");

    /**

     * Provides the caller with the capability to instantiate reflective

     * objects.

     *

     * <p> First, if there is a security manager, its {@code checkPermission}

     * method is called with a {@link java.lang.RuntimePermission} with target

     * {@code "reflectionFactoryAccess"}.  This may result in a security

     * exception.

     *

     * <p> The returned {@code ReflectionFactory} object should be carefully

     * guarded by the caller, since it can be used to read and write private

     * data and invoke private methods, as well as to load unverified bytecodes.

     * It must never be passed to untrusted code.

     *

     * @return the ReflectionFactory

     * @throws SecurityException if a security manager exists and its

     *         {@code checkPermission} method doesn't allow access to

     *         the RuntimePermission "reflectionFactoryAccess".

     */

    public static ReflectionFactory getReflectionFactory() {

        SecurityManager security = System.getSecurityManager();

        if (security != null) {

            security.checkPermission(REFLECTION_FACTORY_ACCESS_PERM);

        }

        return soleInstance;

    }

    /**

     * Returns an accessible constructor capable of creating instances

     * of the given class, initialized by the given constructor.

     *

     * @param cl the class to instantiate

     * @param constructorToCall the constructor to call

     * @return an accessible constructor

     */

    public Constructor<?> newConstructorForSerialization(Class<?> cl,

                                                         Constructor<?> constructorToCall)

    {

        return delegate.newConstructorForSerialization(cl,

                                                       constructorToCall);

    }

    /**

     * Returns an accessible no-arg constructor for a class.

     * The no-arg constructor is found searching the class and its supertypes.

     *

     * @param cl the class to instantiate

     * @return a no-arg constructor for the class or {@code null} if

     *     the class or supertypes do not have a suitable no-arg constructor

     */

    public final Constructor<?> newConstructorForSerialization(Class<?> cl)

    {

        return delegate.newConstructorForSerialization(cl);

    }

    /**

     * Returns an accessible no-arg constructor for an externalizable class to be

     * initialized using a public no-argument constructor.

     *

     * @param cl the class to instantiate

     * @return A no-arg constructor for the class; returns {@code null} if

     *     the class does not implement {@link java.io.Externalizable}

     */

    public final Constructor<?> newConstructorForExternalization(Class<?> cl) {

        return delegate.newConstructorForExternalization(cl);

    }

    /**

     * Returns a direct MethodHandle for the {@code readObject} method on

     * a Serializable class.

     * The first argument of {@link MethodHandle#invoke} is the serializable

     * object and the second argument is the {@code ObjectInputStream} passed to

     * {@code readObject}.

     *

     * @param cl a Serializable class

     * @return  a direct MethodHandle for the {@code readObject} method of the class or

     *          {@code null} if the class does not have a {@code readObject} method

     */

    public final MethodHandle readObjectForSerialization(Class<?> cl) {

        return delegate.readObjectForSerialization(cl);

    }

    /**

     * Returns a direct MethodHandle for the {@code readObjectNoData} method on

     * a Serializable class.

     * The first argument of {@link MethodHandle#invoke} is the serializable

     * object and the second argument is the {@code ObjectInputStream} passed to

     * {@code readObjectNoData}.

     *

     * @param cl a Serializable class

     * @return  a direct MethodHandle for the {@code readObjectNoData} method

     *          of the class or {@code null} if the class does not have a

     *          {@code readObjectNoData} method

     */

    public final MethodHandle readObjectNoDataForSerialization(Class<?> cl) {

        return delegate.readObjectNoDataForSerialization(cl);

    }

    /**

     * Returns a direct MethodHandle for the {@code writeObject} method on

     * a Serializable class.

     * The first argument of {@link MethodHandle#invoke} is the serializable

     * object and the second argument is the {@code ObjectOutputStream} passed to

     * {@code writeObject}.

     *

     * @param cl a Serializable class

     * @return  a direct MethodHandle for the {@code writeObject} method of the class or

     *          {@code null} if the class does not have a {@code writeObject} method

     */

    public final MethodHandle writeObjectForSerialization(Class<?> cl) {

        return delegate.writeObjectForSerialization(cl);

    }

    /**

     * Returns a direct MethodHandle for the {@code readResolve} method on

     * a serializable class.

     * The single argument of {@link MethodHandle#invoke} is the serializable

     * object.

     *

     * @param cl the Serializable class

     * @return  a direct MethodHandle for the {@code readResolve} method of the class or

     *          {@code null} if the class does not have a {@code readResolve} method

     */

    public final MethodHandle readResolveForSerialization(Class<?> cl) {

        return delegate.readResolveForSerialization(cl);

    }

    /**

     * Returns a direct MethodHandle for the {@code writeReplace} method on

     * a serializable class.

     * The single argument of {@link MethodHandle#invoke} is the serializable

     * object.

     *

     * @param cl the Serializable class

     * @return  a direct MethodHandle for the {@code writeReplace} method of the class or

     *          {@code null} if the class does not have a {@code writeReplace} method

     */

    public final MethodHandle writeReplaceForSerialization(Class<?> cl) {

        return delegate.writeReplaceForSerialization(cl);

    }

    /**

     * Returns true if the class has a static initializer.

     * The presence of a static initializer is used to compute the serialVersionUID.

     * @param cl a serializable class

     * @return {@code true} if the class has a static initializer,

     *          otherwise {@code false}

     */

    public final boolean hasStaticInitializerForSerialization(Class<?> cl) {

        return delegate.hasStaticInitializerForSerialization(cl);

    }

    /**

     * Returns a new OptionalDataException with {@code eof} set to {@code true}

     * or {@code false}.

     * @param bool the value of {@code eof} in the created OptionalDataException

     * @return  a new OptionalDataException

     */

    public final OptionalDataException newOptionalDataExceptionForSerialization(boolean bool) {

        Constructor<OptionalDataException> cons = delegate.newOptionalDataExceptionForSerialization();

        try {

            return cons.newInstance(bool);

        } catch (InstantiationException|IllegalAccessException|InvocationTargetException ex) {

            throw new InternalError("unable to create OptionalDataException", ex);

        }

    }

}