R
- the return type of this visitor's methods. Use Void
for visitors that do not need to return results.P
- the type of the additional parameter to this visitor's methods. Use Void
for visitors that do not need an additional parameter.ElementVisitor<R,P>
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 by 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.
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.
Modifier and Type | Field | Description |
---|---|---|
protected final R |
DEFAULT_VALUE |
The specified default value. |
Modifier | Constructor | Description |
---|---|---|
protected |
Deprecated. Release 6 is obsolete; update to a visitor for a newer release level. |
|
protected |
Deprecated. Release 6 is obsolete; update to a visitor for a newer release level. |
Modifier and Type | Method | Description |
---|---|---|
final R |
scan |
Iterates over the given elements and calls scan(Element, P) on each one. |
final R |
scan |
Convenience method equivalent to v.scan(e, null) . |
R |
scan |
Processes an element by calling e.accept(this, p) ; this method may be overridden by subclasses. |
R |
visitExecutable |
Visits an executable element. |
R |
visitPackage |
Visits a package element. |
R |
visitType |
Visits a type element. |
R |
visitTypeParameter |
Visits a type parameter element. |
R |
visitVariable |
Visits a variable element. |
visit, visit, visitModule, visitRecordComponent, visitUnknown
protected final R DEFAULT_VALUE
@Deprecated(since="9") protected ElementScanner6()
null
for the default value.@Deprecated(since="9") protected ElementScanner6(R defaultValue)
defaultValue
- the default valuepublic final R scan(Iterable<? extends Element> iterable, P p)
scan(Element, P)
on each one. Returns the result of the last call to scan
or
DEFAULT_VALUE
for an empty iterable.iterable
- the elements to scanp
- additional parameterDEFAULT_VALUE
if no elementspublic R scan(Element e, P p)
e.accept(this, p)
; this method may be overridden by subclasses.e
- the element to scanp
- a scanner-specified parametere
.public final R scan(Element e)
v.scan(e, null)
.e
- the element to scane
.public R visitPackage(PackageElement e, P p)
e
- the element to visitp
- a visitor-specified parameterpublic R visitType(TypeElement e, P p)
e
- the element to visitp
- a visitor-specified parameterpublic R visitVariable(VariableElement e, P p)
RESOURCE_VARIABLE
in which case
visitUnknown
is called.e
- the element to visitp
- a visitor-specified parameterpublic R visitExecutable(ExecutableElement e, P p)
e
- the element to visitp
- a visitor-specified parameterpublic R visitTypeParameter(TypeParameterElement e, P p)
e
- the element to visitp
- a visitor-specified parameter
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.compiler/javax/lang/model/util/ElementScanner6.html