1 /* 2 * Copyright (c) 2001, 2022, 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 26 package jdk.internal.reflect; 27 28 import java.lang.reflect.Field; 29 import java.lang.reflect.Modifier; 30 31 import jdk.internal.value.PrimitiveClass; 32 import jdk.internal.misc.Unsafe; 33 34 /** Base class for jdk.internal.misc.Unsafe-based FieldAccessors. The 35 observation is that there are only nine types of fields from the 36 standpoint of reflection code: the eight primitive types and 37 Object. Using class Unsafe instead of generated bytecodes saves 38 memory and loading time for the dynamically-generated 39 FieldAccessors. */ 40 41 abstract class UnsafeFieldAccessorImpl extends FieldAccessorImpl { 42 static final Unsafe unsafe = Unsafe.getUnsafe(); 43 44 protected final long fieldOffset; 45 protected final boolean isFinal; 46 47 UnsafeFieldAccessorImpl(Field field) { 48 super(field); 49 int mods = field.getModifiers(); 50 this.isFinal = Modifier.isFinal(mods); 51 if (Modifier.isStatic(mods)) 52 fieldOffset = unsafe.staticFieldOffset(field); 53 else 54 fieldOffset = unsafe.objectFieldOffset(field); 55 } 56 57 protected boolean isFlattened() { 58 return unsafe.isFlattened(field); 59 } 60 61 protected boolean canBeNull() { 62 return !PrimitiveClass.isPrimitiveClass(field.getType()) || 63 PrimitiveClass.isPrimaryType(field.getType()); 64 } 65 66 protected Object checkValue(Object value) { 67 if (!canBeNull() && value == null) 68 throw new NullPointerException(field + " cannot be set to null"); 69 70 if (value != null) { 71 Class<?> type = value.getClass(); 72 if (PrimitiveClass.isPrimitiveClass(type)) { 73 type = PrimitiveClass.asValueType(type); 74 } 75 if (!field.getType().isInstance(value)) { 76 throwSetIllegalArgumentException(value); 77 } 78 } 79 return value; 80 } 81 82 }