Class ElementScanner6<R,P>
- java.lang.Object
-
- javax.lang.model.util.AbstractElementVisitor6<R,P>
-
- javax.lang.model.util.ElementScanner6<R,P>
- 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>
A scanning visitor of program elements with default behavior appropriate for the 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.
Methods in this class may be overridden subject to their general contract. Note that annotating methods in concrete subclasses with @Override
will help ensure that methods are overridden as intended.
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 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 the new visitor is introduced, all or portions of this visitor may be deprecated.
- Since:
- 1.6
- See Also:
-
ElementScanner7
,ElementScanner8
,ElementScanner9
Field Summary
Modifier and Type | Field | Description |
---|---|---|
protected R | DEFAULT_VALUE | The specified default value. |
Constructor Summary
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 calls |
R | scan(Element e) | Convenience method equivalent to |
R | scan(Element e,
P p) | Processes an element by calling |
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, visitUnknown
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Field Detail
DEFAULT_VALUE
protected final R DEFAULT_VALUE
The specified default value.
Constructor Detail
ElementScanner6
@Deprecated(since="9") protected ElementScanner6()
Constructor for concrete subclasses; uses null
for the default value.
ElementScanner6
@Deprecated(since="9") protected ElementScanner6(R defaultValue)
Constructor for concrete subclasses; uses the argument for the default value.
- Parameters:
-
defaultValue
- the default value
Method Detail
scan
public final R scan(Iterable<? extends Element> iterable, P p)
Iterates over the given elements and calls scan(Element, P)
on each one. Returns the result of the last call to scan
or
DEFAULT_VALUE
for an empty iterable.
- Parameters:
-
iterable
- the elements to scan -
p
- additional parameter - Returns:
- the scan of the last element or
DEFAULT_VALUE
if no elements
scan
public R scan(Element e, P p)
Processes an element by calling e.accept(this, p)
; this method may be overridden by subclasses.
- Parameters:
-
e
- the element to scan -
p
- a scanner-specified parameter - Returns:
- the result of visiting
e
.
scan
public final R scan(Element e)
Convenience method equivalent to v.scan(e, null)
.
- Parameters:
-
e
- the element to scan - Returns:
- the result of scanning
e
.
visitPackage
public R visitPackage(PackageElement e, P p)
Visits a package element.
- Implementation Requirements:
- This implementation scans the enclosed elements.
- Parameters:
-
e
- the element to visit -
p
- a visitor-specified parameter - Returns:
- the result of scanning
visitType
public R visitType(TypeElement e, P p)
Visits a type element.
- Implementation Requirements:
- This implementation scans the enclosed elements.
- Parameters:
-
e
- the element to visit -
p
- a visitor-specified parameter - Returns:
- the result of scanning
visitVariable
public R visitVariable(VariableElement e, P p)
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 visit -
p
- a visitor-specified parameter - Returns:
- the result of scanning
visitExecutable
public R visitExecutable(ExecutableElement e, P p)
Visits an executable element.
- Implementation Requirements:
- This implementation scans the parameters.
- Parameters:
-
e
- the element to visit -
p
- a visitor-specified parameter - Returns:
- the result of scanning
visitTypeParameter
public R visitTypeParameter(TypeParameterElement e, P p)
Visits a type parameter element.
- Implementation Requirements:
- This implementation scans the enclosed elements.
- Parameters:
-
e
- the element to visit -
p
- a visitor-specified parameter - Returns:
- the result of scanning