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25 
26 package javax.lang.model.element;
27 
28 
29 /**
30  * Represents a modifier on a program element such
31  * as a class, method, or field.
32  *
33  * <p>Not all modifiers are applicable to all kinds of elements.
34  * When two or more modifiers appear in the source code of an element
35  * then it is customary, though not required, that they appear in the same
36  * order as the constants listed in the detail section below.
37  *
38  * <p>Note that it is possible additional modifiers will be added in
39  * future versions of the platform.
40  *
41  * @jls 8.1.1 Class Modifiers
42  * @jls 8.3.1 Field Modifiers
43  * @jls 8.4.3 Method Modifiers
44  * @jls 8.8.3 Constructor Modifiers
45  * @jls 9.1.1 Interface Modifiers
46  *
47  * @author Joseph D. Darcy
48  * @author Scott Seligman
49  * @author Peter von der Ah&eacute;
50  * @since 1.6
51  */
52 
53 public enum Modifier {
54 
55     // Note java.lang.reflect.Modifier includes INTERFACE, but that's a VMism.
56 
57     /** The modifier {@code public} */          PUBLIC,
58     /** The modifier {@code protected} */       PROTECTED,
59     /** The modifier {@code private} */         PRIVATE,
60     /** The modifier {@code abstract} */        ABSTRACT,
61     /**
62      * The modifier {@code default}
63      * @since 1.8
64      */
65      DEFAULT,
66     /** The modifier {@code static} */          STATIC,
67 
68     /**
69      * {@preview Associated with sealed classes, a preview feature of the Java language.
70      *
71      *           This enum constant is associated with <i>sealed classes</i>, a preview
72      *           feature of the Java language. Preview features
73      *           may be removed in a future release, or upgraded to permanent
74      *           features of the Java language.}
75      *
76      * The modifier {@code sealed}
77      * @since 15
78      */
79     @jdk.internal.PreviewFeature(feature=jdk.internal.PreviewFeature.Feature.SEALED_CLASSES,
80                                              essentialAPI=false)
81     SEALED,
82 
83     /**
84      * {@preview Associated with sealed classes, a preview feature of the Java language.
85      *
86      *           This enum constant is associated with <i>sealed classes</i>, a preview
87      *           feature of the Java language. Preview features
88      *           may be removed in a future release, or upgraded to permanent
89      *           features of the Java language.}
90      *
91      * The modifier {@code non-sealed}
92      * @since 15
93      */
94     @jdk.internal.PreviewFeature(feature=jdk.internal.PreviewFeature.Feature.SEALED_CLASSES,
95             essentialAPI=false)
96     NON_SEALED {
toString()97         public String toString() {
98             return "non-sealed";
99         }
100     },
101     /** The modifier {@code final} */           FINAL,
102     /** The modifier {@code transient} */       TRANSIENT,
103     /** The modifier {@code volatile} */        VOLATILE,
104     /** The modifier {@code synchronized} */    SYNCHRONIZED,
105     /** The modifier {@code native} */          NATIVE,
106     /** The modifier {@code strictfp} */        STRICTFP;
107 
108     /**
109      * Returns this modifier's name as defined in <cite>The
110      * Java Language Specification</cite>.
111      * The modifier name is the {@linkplain #name() name of the enum
112      * constant} in lowercase and with any underscores ("{@code _}")
113      * replaced with hyphens ("{@code -}").
114      * @return the modifier's name
115      */
116     @Override
toString()117     public String toString() {
118         return name().toLowerCase(java.util.Locale.US);
119     }
120 }
121