/*

 * Copyright (c) 1999, 2020, 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.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.ObjectStreamField;

import jdk.internal.access.SharedSecrets;

/**

 * Thrown by a method invocation on a proxy instance if its invocation

 * handler's {@link InvocationHandler#invoke invoke} method throws a

 * checked exception (a {@code Throwable} that is not assignable

 * to {@code RuntimeException} or {@code Error}) that

 * is not assignable to any of the exception types declared in the

 * {@code throws} clause of the method that was invoked on the

 * proxy instance and dispatched to the invocation handler.

 *

 * <p>An {@code UndeclaredThrowableException} instance contains

 * the undeclared checked exception that was thrown by the invocation

 * handler, and it can be retrieved with the

 * {@code getUndeclaredThrowable()} method.

 * {@code UndeclaredThrowableException} extends

 * {@code RuntimeException}, so it is an unchecked exception

 * that wraps a checked exception.

 *

 * @author      Peter Jones

 * @see         InvocationHandler

 * @since       1.3

 */

public class UndeclaredThrowableException extends RuntimeException {

    @java.io.Serial

    static final long serialVersionUID = 330127114055056639L;

    /**

     * Constructs an {@code UndeclaredThrowableException} with the

     * specified {@code Throwable}.

     *

     * @param   undeclaredThrowable the undeclared checked exception

     *          that was thrown

     */

    public UndeclaredThrowableException(Throwable undeclaredThrowable) {

        super(null, undeclaredThrowable);  // Disallow initCause

    }

    /**

     * Constructs an {@code UndeclaredThrowableException} with the

     * specified {@code Throwable} and a detail message.

     *

     * @param   undeclaredThrowable the undeclared checked exception

     *          that was thrown

     * @param   s the detail message

     */

    public UndeclaredThrowableException(Throwable undeclaredThrowable,

                                        String s)

    {

        super(s, undeclaredThrowable);  // Disallow initCause

    }

    /**

     * Returns the {@code Throwable} instance wrapped in this

     * {@code UndeclaredThrowableException}, which may be {@code null}.

     *

     * @apiNote

     * This method predates the general-purpose exception chaining facility.

     * The {@link Throwable#getCause()} method is now the preferred means of

     * obtaining this information.

     *

     * @return the undeclared checked exception that was thrown

     */

    public Throwable getUndeclaredThrowable() {

        return super.getCause();

    }

    /**

     * Serializable fields for UndeclaredThrowableException.

     *

     * @serialField undeclaredThrowable Throwable the undeclared exception

     */

    @java.io.Serial

    private static final ObjectStreamField[] serialPersistentFields = {

        new ObjectStreamField("undeclaredThrowable", Throwable.class)

    };

    /**

     * Reconstitutes the UndeclaredThrowableException instance from a stream

     * and initialize the cause properly when deserializing from an older

     * version.

     *

     * @param  s the {@code ObjectInputStream} from which data is read

     * @throws IOException if an I/O error occurs

     * @throws ClassNotFoundException if a serialized class cannot be loaded

     */

    @java.io.Serial

    private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {

        ObjectInputStream.GetField fields = s.readFields();

        Throwable exception = (Throwable) fields.get("undeclaredThrowable", null);

        if (exception != null) {

            SharedSecrets.getJavaLangAccess().setCause(this, exception);

        }

    }

    /**

     * To maintain compatibility with older implementation, write a serial

     * "ex" field with the cause as the value.

     *

     * @param  out the {@code ObjectOutputStream} to which data is written

     * @throws IOException if an I/O error occurs

     */

    @java.io.Serial

    private void writeObject(ObjectOutputStream out) throws IOException {

        ObjectOutputStream.PutField fields = out.putFields();

        fields.put("undeclaredThrowable", super.getCause());

        out.writeFields();

    }

}