Reflections.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.aries.transaction.jdbc.internal;

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

public final class Reflections {

    private Reflections() {
        // no-op
    }

    public static Object get(final Object instance, String field) {
        Class<?> clazz = instance.getClass();
        while (clazz != null) {
            try {
                final Field f = clazz.getDeclaredField(field);
                final boolean acc = f.isAccessible();
                return AccessController.doPrivileged(new PrivilegedAction<Object>() {
                    @Override
                    public Object run() {
                        f.setAccessible(true);
                        try {
                            return f.get(instance);
                        } catch (IllegalAccessException ex) {
                            throw new IllegalArgumentException(ex);
                        } finally {
                            f.setAccessible(acc);
                        }
                    }
                });
            } catch (NoSuchFieldException nsfe) {
                // no-op
            }

            clazz = clazz.getSuperclass();
        }
        throw new RuntimeException(new NoSuchFieldException(field));
    }
}