1 /* 2 * Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package com.sun.beans.finder; 26 27 import java.lang.reflect.Field; 28 import java.lang.reflect.Modifier; 29 30 import static sun.reflect.misc.ReflectUtil.isPackageAccessible; 31 32 /** 33 * This utility class provides {@code static} methods 34 * to find a public field with specified name 35 * in specified class. 36 * 37 * @since 1.7 38 * 39 * @author Sergey A. Malenkov 40 */ 41 public final class FieldFinder { 42 43 /** 44 * Finds public field (static or non-static) 45 * that is declared in public class. 46 * 47 * @param type the class that can have field 48 * @param name the name of field to find 49 * @return object that represents found field 50 * @throws NoSuchFieldException if field is not found 51 * @see Class#getField 52 */ findField(Class<?> type, String name)53 public static Field findField(Class<?> type, String name) throws NoSuchFieldException { 54 if (name == null) { 55 throw new IllegalArgumentException("Field name is not set"); 56 } 57 Field field = type.getField(name); 58 if (!Modifier.isPublic(field.getModifiers())) { 59 throw new NoSuchFieldException("Field '" + name + "' is not public"); 60 } 61 type = field.getDeclaringClass(); 62 if (!Modifier.isPublic(type.getModifiers()) || !isPackageAccessible(type)) { 63 throw new NoSuchFieldException("Field '" + name + "' is not accessible"); 64 } 65 return field; 66 } 67 68 /** 69 * Finds public non-static field 70 * that is declared in public class. 71 * 72 * @param type the class that can have field 73 * @param name the name of field to find 74 * @return object that represents found field 75 * @throws NoSuchFieldException if field is not found 76 * @see Class#getField 77 */ findInstanceField(Class<?> type, String name)78 public static Field findInstanceField(Class<?> type, String name) throws NoSuchFieldException { 79 Field field = findField(type, name); 80 if (Modifier.isStatic(field.getModifiers())) { 81 throw new NoSuchFieldException("Field '" + name + "' is static"); 82 } 83 return field; 84 } 85 86 /** 87 * Finds public static field 88 * that is declared in public class. 89 * 90 * @param type the class that can have field 91 * @param name the name of field to find 92 * @return object that represents found field 93 * @throws NoSuchFieldException if field is not found 94 * @see Class#getField 95 */ findStaticField(Class<?> type, String name)96 public static Field findStaticField(Class<?> type, String name) throws NoSuchFieldException { 97 Field field = findField(type, name); 98 if (!Modifier.isStatic(field.getModifiers())) { 99 throw new NoSuchFieldException("Field '" + name + "' is not static"); 100 } 101 return field; 102 } 103 104 /** 105 * Disable instantiation. 106 */ FieldFinder()107 private FieldFinder() { 108 } 109 } 110