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25 
26 package javax.lang.model.element;
27 
28 import javax.lang.model.util.Elements;
29 import javax.lang.model.type.TypeMirror;
30 import javax.lang.model.type.TypeKind;
31 
32 /**
33  * Represents a field, {@code enum} constant, method or constructor
34  * parameter, local variable, resource variable, or exception
35  * parameter.
36  *
37  * @author Joseph D. Darcy
38  * @author Scott Seligman
39  * @author Peter von der Ahé
40  * @since 1.6
41  */
42 public interface VariableElement extends Element {
43     /**
44      * Returns the type of this variable.
45      *
46      * Note that the types of variables range over {@linkplain
47      * TypeKind many kinds} of types, including primitive types,
48      * declared types, and array types, among others.
49      *
50      * @return the type of this variable
51      *
52      * @see TypeKind
53      */
54     @Override
asType()55     TypeMirror asType();
56 
57     /**
58      * Returns the value of this variable if this is a {@code final}
59      * field initialized to a compile-time constant.  Returns {@code
60      * null} otherwise.  The value will be of a primitive type or a
61      * {@code String}.  If the value is of a primitive type, it is
62      * wrapped in the appropriate wrapper class (such as {@link
63      * Integer}).
64      *
65      * <p>Note that not all {@code final} fields will have
66      * constant values.  In particular, {@code enum} constants are
67      * <em>not</em> considered to be compile-time constants.  To have a
68      * constant value, a field's type must be either a primitive type
69      * or {@code String}.
70      *
71      * @return the value of this variable if this is a {@code final}
72      * field initialized to a compile-time constant, or {@code null}
73      * otherwise
74      *
75      * @see Elements#getConstantExpression(Object)
76      * @jls 15.28 Constant Expression
77      * @jls 4.12.4 final Variables
78      */
getConstantValue()79     Object getConstantValue();
80 
81     /**
82      * Returns the simple name of this variable element.
83      *
84      * <p>For method and constructor parameters, the name of each
85      * parameter must be distinct from the names of all other
86      * parameters of the same executable.  If the original source
87      * names are not available, an implementation may synthesize names
88      * subject to the distinctness requirement above.
89      *
90      * @return the simple name of this variable element
91      */
92     @Override
getSimpleName()93     Name getSimpleName();
94 
95     /**
96      * Returns the enclosing element of this variable.
97      *
98      * The enclosing element of a method or constructor parameter is
99      * the executable declaring the parameter.
100      *
101      * @return the enclosing element of this variable
102      */
103     @Override
getEnclosingElement()104     Element getEnclosingElement();
105 }
106