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package javax.lang.model.util;
import javax.lang.model.element.*;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import static javax.lang.model.SourceVersion.*;
A simple visitor of program elements with default behavior appropriate for the RELEASE_6
source version. Visit methods corresponding to RELEASE_6
language constructs call defaultAction
, passing their arguments to defaultAction
's corresponding parameters. For constructs introduced in RELEASE_7
and later,
visitUnknown
is called instead. 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 simple element 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.
Author: Joseph D. Darcy, Scott Seligman, Peter von der Ahé Type parameters: See Also: Since: 1.6
/**
* A simple visitor of program elements with default behavior
* appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
* source version.
*
* Visit methods corresponding to {@code RELEASE_6} language
* constructs call {@link #defaultAction defaultAction}, passing their
* arguments to {@code defaultAction}'s corresponding parameters.
*
* For constructs introduced in {@code RELEASE_7} and later, {@code
* visitUnknown} is called instead.
*
* <p> Methods in this class may be overridden subject to their
* general contract. Note that annotating methods in concrete
* subclasses with {@link java.lang.Override @Override} will help
* ensure that methods are overridden as intended.
*
* <p> <b>WARNING:</b> The {@code 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 {@code "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 {@code "visit"}.
*
* <p>When such a new visit method is added, the default
* implementation in this class will be to call the {@link
* #visitUnknown visitUnknown} method. A new simple element 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.
*
* @param <R> the return type of this visitor's methods. Use {@code Void}
* for visitors that do not need to return results.
* @param <P> the type of the additional parameter to this visitor's methods. Use {@code Void}
* for visitors that do not need an additional parameter.
*
* @author Joseph D. Darcy
* @author Scott Seligman
* @author Peter von der Ahé
*
* @see SimpleElementVisitor7
* @see SimpleElementVisitor8
* @see SimpleElementVisitor9
* @see SimpleElementVisitor14
* @since 1.6
*/
@SupportedSourceVersion(RELEASE_6)
public class SimpleElementVisitor6<R, P> extends AbstractElementVisitor6<R, P> {
Default value to be returned;
defaultAction
returns this value unless the method is overridden. /**
* Default value to be returned; {@link #defaultAction
* defaultAction} returns this value unless the method is
* overridden.
*/
protected final R DEFAULT_VALUE;
Constructor for concrete subclasses; uses null
for the default value. Deprecated: Release 6 is obsolete; update to a visitor for a newer
release level.
/**
* Constructor for concrete subclasses; uses {@code null} for the
* default value.
* @deprecated Release 6 is obsolete; update to a visitor for a newer
* release level.
*/
@Deprecated(since="9")
protected SimpleElementVisitor6(){
DEFAULT_VALUE = null;
}
Constructor for concrete subclasses; uses the argument for the
default value.
Params: - defaultValue – the value to assign to
SimpleElementVisitor6<R,P>.DEFAULT_VALUE
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.
*
* @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
* @deprecated Release 6 is obsolete; update to a visitor for a newer
* release level.
*/
@Deprecated(since="9")
protected SimpleElementVisitor6(R defaultValue){
DEFAULT_VALUE = defaultValue;
}
The default action for visit methods.
Params: - e – the element to process
- p – a visitor-specified parameter
Implementation Requirements: The implementation in this class just returns SimpleElementVisitor6<R,P>.DEFAULT_VALUE
; subclasses will commonly override this method. Returns: DEFAULT_VALUE
unless overridden
/**
* The default action for visit methods.
*
* @implSpec The implementation in this class just returns {@link
* #DEFAULT_VALUE}; subclasses will commonly override this method.
*
* @param e the element to process
* @param p a visitor-specified parameter
* @return {@code DEFAULT_VALUE} unless overridden
*/
protected R defaultAction(Element e, P p) {
return DEFAULT_VALUE;
}
{@inheritDoc}
Params: - e – {@inheritDoc}
- p – {@inheritDoc}
Implementation Requirements: This implementation calls defaultAction
. Returns: {@inheritDoc}
/**
* {@inheritDoc}
*
* @implSpec This implementation calls {@code defaultAction}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
public R visitPackage(PackageElement e, P p) {
return defaultAction(e, p);
}
{@inheritDoc}
Params: - e – {@inheritDoc}
- p – {@inheritDoc}
Implementation Requirements: This implementation calls defaultAction
. Returns: {@inheritDoc}
/**
* {@inheritDoc}
*
* @implSpec This implementation calls {@code defaultAction}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
public R visitType(TypeElement e, P p) {
return defaultAction(e, p);
}
{@inheritDoc}
Params: - e – {@inheritDoc}
- p – {@inheritDoc}
Implementation Requirements: This implementation calls defaultAction
, unless the element is a RESOURCE_VARIABLE
in which case
visitUnknown
is called. Returns: {@inheritDoc}
/**
* {@inheritDoc}
*
* @implSpec This implementation calls {@code defaultAction}, unless the
* element is a {@code RESOURCE_VARIABLE} in which case {@code
* visitUnknown} is called.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
public R visitVariable(VariableElement e, P p) {
if (e.getKind() != ElementKind.RESOURCE_VARIABLE)
return defaultAction(e, p);
else
return visitUnknown(e, p);
}
{@inheritDoc}
Params: - e – {@inheritDoc}
- p – {@inheritDoc}
Implementation Requirements: This implementation calls defaultAction
. Returns: {@inheritDoc}
/**
* {@inheritDoc}
*
* @implSpec This implementation calls {@code defaultAction}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
public R visitExecutable(ExecutableElement e, P p) {
return defaultAction(e, p);
}
{@inheritDoc}
Params: - e – {@inheritDoc}
- p – {@inheritDoc}
Implementation Requirements: This implementation calls defaultAction
. Returns: {@inheritDoc}
/**
* {@inheritDoc}
*
* @implSpec This implementation calls {@code defaultAction}.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return {@inheritDoc}
*/
public R visitTypeParameter(TypeParameterElement e, P p) {
return defaultAction(e, p);
}
}