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. 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>
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 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.

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.

Since:
1.6
See Also:

  • Field Summary

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

  • Constructor Summary

    Constructors
    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
    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
    visitExecutable(ExecutableElement e, P p)
    Visits an executable element.
    R
    visitPackage(PackageElement e, P p)
    Visits a package element.
    R
    visitRecordComponent(RecordComponentElement e, P p)
    Visits a record component 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 AbstractElementVisitor6

    visit, visit, visitModule, 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
    visitModule(ModuleElement e, P p)
    Visits a module element.
    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.

  • Field Details

    • DEFAULT_VALUE

      protected final R DEFAULT_VALUE
      The specified default value.

  • Constructor Details

    • ElementScanner6

      @Deprecated(since="9") protected ElementScanner6()
      Deprecated.
      Release 6 is obsolete; update to a visitor for a newer release level.
      Constructor for concrete subclasses; uses null for the default value.

    • ElementScanner6

      @Deprecated(since="9") protected ElementScanner6(R defaultValue)
      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.
      Parameters:
      defaultValue - the default value

  • Method Details

    • 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. Note that type parameters are not scanned by this implementation since type parameters are not considered to be enclosed elements of a type.
      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 case visitUnknown 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. Note that type parameters are not scanned by this implementation.
      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

    • visitRecordComponent

      public R visitRecordComponent(RecordComponentElement e, P p)
      Visits a record component element.
      Specified by:
      visitRecordComponent in interface ElementVisitor<R,P>
      Overrides:
      visitRecordComponent in class AbstractElementVisitor6<R,P>
      Implementation Requirements:
      This implementation calls visitUnknown(e, p).
      Parameters:
      e - the element to visit
      p - a visitor-specified parameter
      Returns:
      the result of scanning
      Since:
      14