Class ElementScannerPreview<R,P>

java.lang.Object

javax.lang.model.util.AbstractElementVisitor6<R,P>

javax.lang.model.util.ElementScanner6<R,P>

javax.lang.model.util.ElementScanner7<R,P>

javax.lang.model.util.ElementScanner8<R,P>

javax.lang.model.util.ElementScanner9<R,P>

javax.lang.model.util.ElementScanner14<R,P>

javax.lang.model.util.ElementScannerPreview<R,P>

Type Parameters:

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.

All Implemented Interfaces:

ElementVisitor<R,P>

@SupportedSourceVersion(RELEASE_26)
public class ElementScannerPreview<R,P>
extends ElementScanner14<R,P>

ElementScannerPreview is a reflective preview API of the Java platform.

Preview features may be removed in a future release, or upgraded to permanent features of the Java platform.

A scanning visitor of program elements with default behavior appropriate for a preview 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.

API Note:

Methods in this class may be overridden subject to their general contract.

Since:

23

See Also:

• Expected visitor evolution
• Compatibility note for subclasses
• ElementScanner6
• ElementScanner7
• ElementScanner8
• ElementScanner9
• ElementScanner14

Field Summary

Fields declared in class ElementScanner6

DEFAULT_VALUE

Modifier and Type	Field	Description
protected final R	DEFAULT_VALUE	The specified default value.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ElementScannerPreview()	Constructor for concrete subclasses; uses null for the default value.
protected	ElementScannerPreview(R defaultValue)	Constructor for concrete subclasses; uses the argument for the default value.

Method Summary

Methods declared in class ElementScanner14

visitExecutable, visitRecordComponent, visitType

Modifier and Type	Method	Description
R	visitExecutable(ExecutableElement e, P p)	Visits an executable element.
R	visitRecordComponent(RecordComponentElement e, P p)	Visits a record component element.
R	visitType(TypeElement e, P p)	Visits a type element.

Methods declared in class ElementScanner9

visitModule

Modifier and Type	Method	Description
R	visitModule(ModuleElement e, P p)	Visits a module element.

Methods declared in class ElementScanner7

visitVariable

Modifier and Type	Method	Description
R	visitVariable(VariableElement e, P p)	Visits a variable element.

Methods declared in class ElementScanner6

scan, scan, scan, visitPackage, visitTypeParameter

Modifier and Type	Method	Description
final R	scan(Iterable<? extends Element> iterable, P p)	Iterates over the given elements and calls scan(Element, P) on each one.
final R	scan(Element e)	Convenience method equivalent to v.scan(e, null).
R	scan(Element e, P p)	Processes an element by calling e.accept(this, p); this method may be overridden by subclasses.
R	visitPackage(PackageElement e, P p)	Visits a package element.
R	visitTypeParameter(TypeParameterElement e, P p)	Visits a type parameter element.

Methods declared in class AbstractElementVisitor6

visit, visit, visitUnknown

Modifier and Type	Method	Description
final R	visit(Element e)	Visits any program element as if by passing itself to that element's accept method and passing null for the additional parameter.
final R	visit(Element e, P p)	Visits any program element as if by passing itself to that element's accept method.
R	visitUnknown(Element e, P p)	Visits an unknown kind of element.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for this object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
String	toString()	Returns a string representation of the object.
final void	wait()	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
final void	wait(long timeoutMillis)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
final void	wait(long timeoutMillis, int nanos)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

ElementScannerPreview

protected ElementScannerPreview()

Constructor for concrete subclasses; uses null for the default value.

ElementScannerPreview

protected ElementScannerPreview(R defaultValue)

Constructor for concrete subclasses; uses the argument for the default value.

Parameters:

defaultValue - the default value