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 package java.lang.classfile.attribute;
26 
27 import java.lang.constant.ClassDesc;
28 import java.util.Arrays;
29 import java.util.List;
30 
31 import java.lang.classfile.Attribute;
32 import java.lang.classfile.ClassElement;
33 import java.lang.classfile.constantpool.ClassEntry;
34 import jdk.internal.classfile.impl.BoundAttribute;
35 import jdk.internal.classfile.impl.UnboundAttribute;
36 import jdk.internal.classfile.impl.Util;
37 import jdk.internal.javac.PreviewFeature;
38 
39 /**
40  *  <p><b>This is NOT part of any supported API.
41  *  If you write code that depends on this, you do so at your own risk.
42  *  This code and its internal interfaces are subject to change or
43  *  deletion without notice.</b>
44  */
45 @PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
46 public sealed interface PreloadAttribute
47         extends Attribute<PreloadAttribute>, ClassElement
48         permits BoundAttribute.BoundPreloadAttribute, UnboundAttribute.UnboundPreloadAttribute {
49 
50     /**
51      * {@return the list of preload classes}
52      */
53     List<ClassEntry> preloads();
54 
55     /**
56      * {@return a {@code Preload} attribute}
57      * @param preloads the preload classes
58      */
59     static PreloadAttribute of(List<ClassEntry> preloads) {
60         return new UnboundAttribute.UnboundPreloadAttribute(preloads);
61     }
62 
63     /**
64      * {@return a {@code Preload} attribute}
65      * @param preloads the preload classes
66      */
67     static PreloadAttribute of(ClassEntry... preloads) {
68         return of(List.of(preloads));
69     }
70 
71     /**
72      * {@return a {@code Preload} attribute}
73      * @param preloads the preload classes
74      */
75     static PreloadAttribute ofSymbols(List<ClassDesc> preloads) {
76         return of(Util.entryList(preloads));
77     }
78 
79     /**
80      * {@return a {@code Preload} attribute}
81      * @param preloads the preload classes
82      */
83     static PreloadAttribute ofSymbols(ClassDesc... preloads) {
84         return ofSymbols(Arrays.asList(preloads));
85     }
86 }