/*

 * Copyright (c) 2001, 2019, 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 org.xml.sax.helpers;

import java.lang.reflect.InvocationTargetException;

import java.util.Objects;

/**

 * Create a new instance of a class by name.

 *

 *

 * <p>This class contains a static method for creating an instance of a

 * class from an explicit class name.  It tries to use the thread's context

 * ClassLoader if possible and falls back to using

 * Class.forName(String).</p>

 *

 * <p>This code is designed to compile and run on JDK version 1.1 and later

 * including versions of Java 2.</p>

 *

 * @author Edwin Goei, David Brownell

 * @version 2.0.1 (sax2r2)

 */

class NewInstance {

    private static final String DEFAULT_PACKAGE = "com.sun.org.apache.xerces.internal";

    private static final String DEFAULT_CLASS = "com.sun.org.apache.xerces.internal.parsers.SAXParser";

    /**

     * Creates a new instance of the specified class name

     *

     * Package private so this code is not exposed at the API level.

     */

    static <T> T newInstance (Class<T> type, ClassLoader loader, String clsName)

        throws ClassNotFoundException, IllegalAccessException,

            InstantiationException

    {

        ClassLoader classLoader = Objects.requireNonNull(loader);

        String className = Objects.requireNonNull(clsName);

        // Instantiate directly for the SAX default parser

        if (className.equals(DEFAULT_CLASS)) {

            return type.cast(new com.sun.org.apache.xerces.internal.parsers.SAXParser());

        }

        // make sure we have access to restricted packages

        boolean internal = false;

        if (System.getSecurityManager() != null) {

            if (className != null && className.startsWith(DEFAULT_PACKAGE)) {

                internal = true;

            }

        }

        Class<?> driverClass;

        if (classLoader == null || internal) {

            driverClass = Class.forName(className);

        } else {

            driverClass = classLoader.loadClass(className);

        }

        try {

            return type.cast(driverClass.getConstructor().newInstance());

        } catch (NoSuchMethodException | SecurityException | InvocationTargetException ex) {

            throw new InstantiationException(ex.getMessage());

        }

    }

}