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 * 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.
 *
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package org.xml.sax.helpers;

import java.lang.reflect.InvocationTargetException;
import java.util.Objects;

Create a new instance of a class by name.
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).
This code is designed to compile and run on JDK version 1.1 and later
including versions of Java 2.
Author:
Edwin Goei, David Brownell
Version:
2.0.1 (sax2r2)/**
 * 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.
/**
     * 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());
        }
    }

}