- Type Parameters:
R- the return type of this visitor's methods. Use
Voidfor visitors that do not need to return results.
P- the type of the additional parameter to this visitor's methods. Use
Voidfor visitors that do not need an additional parameter.
- All Implemented Interfaces:
@SupportedSourceVersion(RELEASE_12) public class ElementScanner9<R,P> extends ElementScanner8<R,P>A scanning visitor of program elements with default behavior appropriate for source versions
visitXyzmethods in this class scan their component elements by calling
scanon their enclosed elements, parameters, etc., as indicated in the individual method specifications. A subclass can control the order elements are visited by overriding the
visitXyzmethods. 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
visitXyzmethod, 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.visitXyzat 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
scanwith the elements in the desired order.
Methods in this class may be overridden subject to their general contract. Note that annotating methods in concrete subclasses with
@Overridewill help ensure that methods are overridden as intended.
ElementVisitorinterface 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
When such a new visit method is added, the default implementation in this class will be to call the
visitUnknownmethod. 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 the new visitor is introduced, all or portions of this visitor may be deprecated.
Methods declared in class javax.lang.model.util.ElementScanner6
scan, scan, scan, visitExecutable, visitPackage, visitType, visitTypeParameter
protected ElementScanner9()Constructor for concrete subclasses; uses
nullfor the default value.
protected ElementScanner9(R defaultValue)Constructor for concrete subclasses; uses the argument for the default value.
defaultValue- the default value
public R visitModule(ModuleElement e, P p)Visits a module element.
- Specified by:
- Implementation Requirements:
- This implementation scans the enclosed elements.
e- the element to visit
p- a visitor-specified parameter
- the result of the scan