Interface AnnotationValueVisitor<R,P>
- Type Parameters:
-
R
- the return type of this visitor's methods -
P
- the type of the additional parameter to this visitor's methods.
- All Known Implementing Classes:
-
AbstractAnnotationValueVisitor6
,AbstractAnnotationValueVisitor7
,AbstractAnnotationValueVisitor8
,AbstractAnnotationValueVisitor9
,SimpleAnnotationValueVisitor6
,SimpleAnnotationValueVisitor7
,SimpleAnnotationValueVisitor8
,SimpleAnnotationValueVisitor9
public interface AnnotationValueVisitor<R,P>
A visitor of the values of annotation type elements, using a variant of the visitor design pattern. Unlike a standard visitor which dispatches based on the concrete type of a member of a type hierarchy, this visitor dispatches based on the type of data stored; there are no distinct subclasses for storing, for example, boolean
values versus int
values. Classes implementing this interface are used to operate on a value when the type of that value is unknown at compile time. When a visitor is passed to a value's accept
method, the visitXyz
method applicable to that value is invoked.
Classes implementing this interface may or may not throw a NullPointerException
if the additional parameter p
is null
; see documentation of the implementing class for details.
WARNING: It is possible that methods will be added to this interface to accommodate new, currently unknown, language structures added to future versions of the Java™ programming language. Therefore, visitor classes directly implementing this interface may be source incompatible with future versions of the platform. To avoid this source incompatibility, visitor implementations are encouraged to instead extend the appropriate abstract visitor class that implements this interface. However, an API should generally use this visitor interface as the type for parameters, return type, etc. rather than one of the abstract classes.
Note that methods to accommodate new language constructs could be added in a source compatible way if they were added as default methods. However, default methods are only available on Java SE 8 and higher releases and the
javax.lang.model.*
packages bundled in Java SE 8 were required to also be runnable on Java SE 7. Therefore, default methods were not used when extending javax.lang.model.*
to cover Java SE 8 language features. However, default methods are used in subsequent revisions of the javax.lang.model.*
packages that are only required to run on Java SE 8 and higher platform versions.
- Since:
- 1.6
Method Summary
Modifier and Type | Method | Description |
---|---|---|
default R | visit(AnnotationValue av) | A convenience method equivalent to |
R | visit(AnnotationValue av,
P p) | Visits an annotation value. |
R | visitAnnotation(AnnotationMirror a,
P p) | Visits an annotation value in an annotation. |
R | visitArray(List<? extends AnnotationValue> vals,
P p) | Visits an array value in an annotation. |
R | visitBoolean(boolean b,
P p) | Visits a |
R | visitByte(byte b,
P p) | Visits a |
R | visitChar(char c,
P p) | Visits a |
R | visitDouble(double d,
P p) | Visits a |
R | visitEnumConstant(VariableElement c,
P p) | Visits an |
R | visitFloat(float f,
P p) | Visits a |
R | visitInt(int i,
P p) | Visits an |
R | visitLong(long i,
P p) | Visits a |
R | visitShort(short s,
P p) | Visits a |
R | visitString(String s,
P p) | Visits a string value in an annotation. |
R | visitType(TypeMirror t,
P p) | Visits a type value in an annotation. |
R | visitUnknown(AnnotationValue av,
P p) | Visits an unknown kind of annotation value. |
Method Detail
visit
R visit(AnnotationValue av, P p)
Visits an annotation value.
- Parameters:
-
av
- the value to visit -
p
- a visitor-specified parameter - Returns:
- a visitor-specified result
visit
default R visit(AnnotationValue av)
A convenience method equivalent to visit(av, null)
.
- Implementation Requirements:
- The default implementation is
visit(av, null)
. - Parameters:
-
av
- the value to visit - Returns:
- a visitor-specified result
visitBoolean
R visitBoolean(boolean b, P p)
Visits a boolean
value in an annotation.
- Parameters:
-
b
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitByte
R visitByte(byte b, P p)
Visits a byte
value in an annotation.
- Parameters:
-
b
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitChar
R visitChar(char c, P p)
Visits a char
value in an annotation.
- Parameters:
-
c
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitDouble
R visitDouble(double d, P p)
Visits a double
value in an annotation.
- Parameters:
-
d
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitFloat
R visitFloat(float f, P p)
Visits a float
value in an annotation.
- Parameters:
-
f
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitInt
R visitInt(int i, P p)
Visits an int
value in an annotation.
- Parameters:
-
i
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitLong
R visitLong(long i, P p)
Visits a long
value in an annotation.
- Parameters:
-
i
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitShort
R visitShort(short s, P p)
Visits a short
value in an annotation.
- Parameters:
-
s
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitString
R visitString(String s, P p)
Visits a string value in an annotation.
- Parameters:
-
s
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitType
R visitType(TypeMirror t, P p)
Visits a type value in an annotation.
- Parameters:
-
t
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitEnumConstant
R visitEnumConstant(VariableElement c, P p)
Visits an enum
value in an annotation.
- Parameters:
-
c
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitAnnotation
R visitAnnotation(AnnotationMirror a, P p)
Visits an annotation value in an annotation.
- Parameters:
-
a
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitArray
R visitArray(List<? extends AnnotationValue> vals, P p)
Visits an array value in an annotation.
- Parameters:
-
vals
- the value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
visitUnknown
R visitUnknown(AnnotationValue av, P p)
Visits an unknown kind of annotation value. This can occur if the language evolves and new kinds of value can be stored in an annotation.
- Parameters:
-
av
- the unknown value being visited -
p
- a visitor-specified parameter - Returns:
- the result of the visit
- Throws:
-
UnknownAnnotationValueException
- a visitor implementation may optionally throw this exception