Java example source code file (Reflect.java)

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Java - Java tags/keywords

accessibleobject, assertionerror, class, classnotfoundexception, field, nosuchfieldexception, override, privilegedaction, reflect, reflection, security, string

The Reflect.java Java example source code

/*
 * Copyright (c) 2008, 2009, 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.nio.fs;

import java.lang.reflect.*;
import java.security.AccessController;
import java.security.PrivilegedAction;

/**
 * Utility class for reflection.
 */

class Reflect {
    private Reflect() {}

    private static void setAccessible(final AccessibleObject ao) {
        AccessController.doPrivileged(new PrivilegedAction<Object>() {
                @Override
                public Object run() {
                    ao.setAccessible(true);
                    return null;
                }});
    }

    /**
     * Lookup the field of a given class.
     */
    static Field lookupField(String className, String fieldName) {
        try {
            Class<?> cl = Class.forName(className);
            Field f = cl.getDeclaredField(fieldName);
            setAccessible(f);
            return f;
        } catch (ClassNotFoundException x) {
            throw new AssertionError(x);
        } catch (NoSuchFieldException x) {
            throw new AssertionError(x);
        }
    }
}