1 /* 2 * Copyright (c) 2019, 2020, 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.javac; 27 28 import java.lang.annotation.*; 29 30 /** 31 * Indicates the API declaration in question is associated with a 32 * <em>preview feature</em>. See JEP 12: "Preview Language and VM 33 * Features" (http://openjdk.java.net/jeps/12). 34 * 35 * Note this internal annotation is handled specially by the javac compiler. 36 * To work properly with {@code --release older-release}, it requires special 37 * handling in {@code make/langtools/src/classes/build/tools/symbolgenerator/CreateSymbols.java} 38 * and {@code src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java}. 39 * 40 * @since 14 41 */ 42 // Match the meaningful targets of java.lang.Deprecated, omit local 43 // variables and parameter declarations 44 @Target({ElementType.METHOD, 45 ElementType.CONSTRUCTOR, 46 ElementType.FIELD, 47 ElementType.PACKAGE, 48 ElementType.MODULE, 49 ElementType.TYPE}) 50 // CLASS retention will hopefully be sufficient for the purposes at hand 51 @Retention(RetentionPolicy.CLASS) 52 // *Not* @Documented 53 public @interface PreviewFeature { 54 /** 55 * Name of the preview feature the annotated API is associated 56 * with. 57 */ feature()58 public Feature feature(); 59 reflective()60 public boolean reflective() default false; 61 62 public enum Feature { 63 /* 64 * This one can only be removed after JDK 17 65 */ 66 SEALED_CLASSES, 67 SWITCH_PATTERN_MATCHING, 68 /** 69 * A key for testing. 70 */ 71 TEST, 72 ; 73 } 74 } 75