Here you can find the source of findDeclaredField(Class javaClass, String fieldName)
private static Field findDeclaredField(Class javaClass, String fieldName) throws NoSuchFieldException
//package com.java2s; /*// w w w. j a va2s .c om * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * // Copyright (c) 1998, 2007, Oracle. All rights reserved. * * * 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 https://glassfish.dev.java.net/public/CDDL+GPL.html * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. * Sun designates this particular file as subject to the "Classpath" exception * as provided by Sun in the GPL Version 2 section of the License file that * accompanied this code. If applicable, add the following below the License * Header, with the fields enclosed by brackets [] replaced by your own * identifying information: "Portions Copyrighted [year] * [name of copyright owner]" * * Contributor(s): * * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ import java.lang.reflect.*; public class Main { /** * Finding a field within a class potentially has to navigate through it's superclasses to eventually * find the field. This method is called by the public getDeclaredField() method and does a recursive * search for the named field in the given classes or it's superclasses. */ private static Field findDeclaredField(Class javaClass, String fieldName) throws NoSuchFieldException { try { return javaClass.getDeclaredField(fieldName); } catch (NoSuchFieldException ex) { Class superclass = javaClass.getSuperclass(); if (superclass == null) { throw ex; } else { return findDeclaredField(superclass, fieldName); } } } /** * Get a field actually declared in a class and wrap the call in doPrivileged if necessary. * The shouldSetAccessible parameter allows the the setAccessible API to be called as well. * This option was added to avoid making multiple doPrivileged calls within InstanceVariableAttributeAccessor. * @param javaClass The class to get the field from * @param fieldName The name of the field * @param shouldSetAccessible whether or not to call the setAccessible API * @throws java.lang.NoSuchFieldException */ public static Field getDeclaredField(final Class javaClass, final String fieldName, final boolean shouldSetAccessible) throws NoSuchFieldException { Field field = javaClass.getDeclaredField(fieldName); if (shouldSetAccessible) { field.setAccessible(true); } return field; } }