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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
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 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
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 * When distributing the software, include this License Header Notice in each
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 * GPL Classpath Exception:
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package org.glassfish.jersey.linking;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Utility class for working with class fields
 *
 * @author Mark Hadley
 * @author Gerard Davison (gerard.davison at oracle.com)
 */
class FieldDescriptor {

    protected Field field;

    FieldDescriptor(Field f) {
        this.field = f;
    }

    public Object getFieldValue(Object instance) {
        setAccessibleField(field);
        Object value = null;
        try {
            value = field.get(instance);
        } catch (IllegalArgumentException | IllegalAccessException ex) {
            Logger.getLogger(FieldDescriptor.class.getName()).log(Level.FINE, null, ex);
        }
        return value;
    }

    public String getFieldName() {
        return field.getName();
    }

    protected static void setAccessibleField(final Field f) {
        if (Modifier.isPublic(f.getModifiers())) {
            return;
        }

        AccessController.doPrivileged(new PrivilegedAction<Object>() {
            public Object run() {
                if (!f.isAccessible()) {
                    f.setAccessible(true);
                }
                return f;
            }
        });
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final FieldDescriptor other = (FieldDescriptor) obj;
        if (this.field != other.field && (this.field == null || !this.field.equals(other.field))) {
            return false;
        }
        return true;
    }

    @Override
    public int hashCode() {
        int hash = 7;
        hash = 83 * hash + (this.field != null ? this.field.hashCode() : 0);
        return hash;
    }

}
