1 /* 2 * Copyright (c) 2024, 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.value; 27 28 public final class NullRestrictedCheckedType implements CheckedType { 29 private final Class<?> type; 30 private NullRestrictedCheckedType(Class<?> cls) { 31 this.type = cls; 32 } 33 34 @Override 35 public Object cast(Object obj) { 36 if (obj == null) { 37 throw new NullPointerException("null not allowed for null-restricted type " + type.getName()); 38 } 39 return type.cast(obj); 40 } 41 42 @Override 43 public boolean canCast(Object obj) { 44 if (obj == null) return false; 45 return type.isAssignableFrom(obj.getClass()); 46 } 47 48 @Override 49 public Class<?> boundingClass() { 50 return type; 51 } 52 53 /** 54 * {@returns a {@linkplain NullRestrictedCheckedType null-restricted checked type} 55 * for the given class if it is a checked type} 56 * 57 * A primitive type and {@code void} is not a checked type. 58 * 59 * @param cls {@code Class} object 60 * @throws IllegalArgumentException if the given class is a primitive type 61 * @throws IllegalArgumentException if the given class is not a value class 62 */ 63 public static NullRestrictedCheckedType of(Class<?> cls) { 64 if (cls.isPrimitive()) 65 throw new IllegalArgumentException(cls.getName() + " not a checked type"); 66 if (!cls.isValue()) { 67 throw new IllegalArgumentException(cls.getName() + " not a value class"); 68 } 69 return new NullRestrictedCheckedType(cls); 70 } 71 }