- Type Parameters:
R
- the return type of this visitor's methods. UseVoid
for visitors that do not need to return results.P
- the type of the additional parameter to this visitor's methods. UseVoid
for visitors that do not need an additional parameter.
- All Implemented Interfaces:
ElementVisitor<R,P>
- Direct Known Subclasses:
ElementScanner7
@SupportedSourceVersion(RELEASE_6) public class ElementScanner6<R,P> extends AbstractElementVisitor6<R,P>
RELEASE_6
source version. The visitXyz
methods in this
class scan their component elements by calling scan
on
their enclosed elements,
parameters, etc., as
indicated in the individual method specifications. A subclass can
control the order elements are visited by overriding the
visitXyz
methods. Note that clients of a scanner
may get the desired behavior be invoking v.scan(e, p)
rather
than v.visit(e, p)
on the root objects of interest.
When a subclass overrides a visitXyz
method, the
new method can cause the enclosed elements to be scanned in the
default way by calling super.visitXyz
. In this
fashion, the concrete visitor can control the ordering of traversal
over the component elements with respect to the additional
processing; for example, consistently calling
super.visitXyz
at the start of the overridden
methods will yield a preorder traversal, etc. If the component
elements should be traversed in some other order, instead of
calling super.visitXyz
, an overriding visit method
should call scan
with the elements in the desired order.
- API Note:
- Methods in this class may be overridden subject to their general
contract.
WARNING: The
ElementVisitor
interface implemented by this class may have methods added to it in the future to accommodate new, currently unknown, language structures added to future versions of the Java programming language. Therefore, methods whose names begin with"visit"
may be added to this class in the future; to avoid incompatibilities, classes which extend this class should not declare any instance methods with names beginning with"visit"
.When such a new visit method is added, the default implementation in this class will be to directly or indirectly call the
visitUnknown
method. A new element scanner visitor class will also be introduced to correspond to the new language level; this visitor will have different default behavior for the visit method in question. When a new visitor is introduced, portions of this visitor class may be deprecated, including its constructors. - Since:
- 1.6
- See Also:
ElementScanner7
,ElementScanner8
,ElementScanner9
,ElementScanner14
-
Field Summary
Fields Modifier and Type Field Description protected R
DEFAULT_VALUE
The specified default value. -
Constructor Summary
Constructors Modifier Constructor Description protected
ElementScanner6()
Deprecated.Release 6 is obsolete; update to a visitor for a newer release level.protected
ElementScanner6(R defaultValue)
Deprecated.Release 6 is obsolete; update to a visitor for a newer release level. -
Method Summary
Modifier and Type Method Description R
scan(Iterable<? extends Element> iterable, P p)
Iterates over the given elements and callsscan(Element, P)
on each one.R
scan(Element e)
Convenience method equivalent tov.scan(e, null)
.R
scan(Element e, P p)
Processes an element by callinge.accept(this, p)
; this method may be overridden by subclasses.R
visitExecutable(ExecutableElement e, P p)
Visits an executable element.R
visitPackage(PackageElement e, P p)
Visits a package element.R
visitType(TypeElement e, P p)
Visits a type element.R
visitTypeParameter(TypeParameterElement e, P p)
Visits a type parameter element.R
visitVariable(VariableElement e, P p)
Visits a variable element.Methods declared in class javax.lang.model.util.AbstractElementVisitor6
visit, visit, visitModule, visitRecordComponent, visitUnknown
-
Field Details
-
DEFAULT_VALUE
The specified default value.
-
-
Constructor Details
-
ElementScanner6
Deprecated.Release 6 is obsolete; update to a visitor for a newer release level.Constructor for concrete subclasses; usesnull
for the default value. -
ElementScanner6
Deprecated.Release 6 is obsolete; update to a visitor for a newer release level.Constructor for concrete subclasses; uses the argument for the default value.- Parameters:
defaultValue
- the default value
-
-
Method Details
-
scan
Iterates over the given elements and callsscan(Element, P)
on each one. Returns the result of the last call toscan
orDEFAULT_VALUE
for an empty iterable.- Parameters:
iterable
- the elements to scanp
- additional parameter- Returns:
- the scan of the last element or
DEFAULT_VALUE
if no elements
-
scan
Processes an element by callinge.accept(this, p)
; this method may be overridden by subclasses.- Parameters:
e
- the element to scanp
- a scanner-specified parameter- Returns:
- the result of visiting
e
.
-
scan
Convenience method equivalent tov.scan(e, null)
.- Parameters:
e
- the element to scan- Returns:
- the result of scanning
e
.
-
visitPackage
Visits a package element.- Implementation Requirements:
- This implementation scans the enclosed elements.
- Parameters:
e
- the element to visitp
- a visitor-specified parameter- Returns:
- the result of scanning
-
visitType
Visits a type element.- Implementation Requirements:
- This implementation scans the enclosed elements. Note that type parameters are not scanned by this implementation since type parameters are not considered to be enclosed elements of a type.
- Parameters:
e
- the element to visitp
- a visitor-specified parameter- Returns:
- the result of scanning
-
visitVariable
Visits a variable element.- Implementation Requirements:
- This implementation scans the enclosed elements, unless the
element is a
RESOURCE_VARIABLE
in which casevisitUnknown
is called. - Parameters:
e
- the element to visitp
- a visitor-specified parameter- Returns:
- the result of scanning
-
visitExecutable
Visits an executable element.- Implementation Requirements:
- This implementation scans the parameters. Note that type parameters are not scanned by this implementation.
- Parameters:
e
- the element to visitp
- a visitor-specified parameter- Returns:
- the result of scanning
-
visitTypeParameter
Visits a type parameter element.- Implementation Requirements:
- This implementation scans the enclosed elements.
- Parameters:
e
- the element to visitp
- a visitor-specified parameter- Returns:
- the result of scanning
-