Module java.compiler
Package javax.lang.model.element

Interface AnnotationValueVisitor<R,​P>

  • Type Parameters:
    R - the return type of this visitor's methods
    P - the type of the additional parameter to this visitor's methods.
    All Known Implementing Classes:
    AbstractAnnotationValueVisitor6, AbstractAnnotationValueVisitor7, AbstractAnnotationValueVisitor8, AbstractAnnotationValueVisitor9, SimpleAnnotationValueVisitor6, SimpleAnnotationValueVisitor7, SimpleAnnotationValueVisitor8, SimpleAnnotationValueVisitor9
    public interface AnnotationValueVisitor<R,​P>
    A visitor of the values of annotation type elements, using a variant of the visitor design pattern. Unlike a standard visitor which dispatches based on the concrete type of a member of a type hierarchy, this visitor dispatches based on the type of data stored; there are no distinct subclasses for storing, for example, boolean values versus int values. Classes implementing this interface are used to operate on a value when the type of that value is unknown at compile time. When a visitor is passed to a value's accept method, the visitXyz method applicable to that value is invoked.

    Classes implementing this interface may or may not throw a NullPointerException if the additional parameter p is null; see documentation of the implementing class for details.

    WARNING: It is possible that methods will be added to this interface to accommodate new, currently unknown, language structures added to future versions of the Java™ programming language. Therefore, visitor classes directly implementing this interface may be source incompatible with future versions of the platform. To avoid this source incompatibility, visitor implementations are encouraged to instead extend the appropriate abstract visitor class that implements this interface. However, an API should generally use this visitor interface as the type for parameters, return type, etc. rather than one of the abstract classes.

    Note that methods to accommodate new language constructs could be added in a source compatible way if they were added as default methods. However, default methods are only available on Java SE 8 and higher releases and the javax.lang.model.* packages bundled in Java SE 8 were required to also be runnable on Java SE 7. Therefore, default methods were not used when extending javax.lang.model.* to cover Java SE 8 language features. However, default methods are used in subsequent revisions of the javax.lang.model.* packages that are only required to run on Java SE 8 and higher platform versions.

    Since:
    1.6

    • Method Detail

      • visit

        R visit​(AnnotationValue av,
        P p)
        Visits an annotation value.
        Parameters:
        av - the value to visit
        p - a visitor-specified parameter
        Returns:
        a visitor-specified result

      • visit

        default R visit​(AnnotationValue av)
        A convenience method equivalent to visit(av, null).
        Implementation Requirements:
        The default implementation is visit(av, null).
        Parameters:
        av - the value to visit
        Returns:
        a visitor-specified result

      • visitBoolean

        R visitBoolean​(boolean b,
               P p)
        Visits a boolean value in an annotation.
        Parameters:
        b - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitByte

        R visitByte​(byte b,
            P p)
        Visits a byte value in an annotation.
        Parameters:
        b - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitChar

        R visitChar​(char c,
            P p)
        Visits a char value in an annotation.
        Parameters:
        c - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitDouble

        R visitDouble​(double d,
              P p)
        Visits a double value in an annotation.
        Parameters:
        d - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitFloat

        R visitFloat​(float f,
             P p)
        Visits a float value in an annotation.
        Parameters:
        f - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitInt

        R visitInt​(int i,
           P p)
        Visits an int value in an annotation.
        Parameters:
        i - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitLong

        R visitLong​(long i,
            P p)
        Visits a long value in an annotation.
        Parameters:
        i - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitShort

        R visitShort​(short s,
             P p)
        Visits a short value in an annotation.
        Parameters:
        s - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitString

        R visitString​(String s,
              P p)
        Visits a string value in an annotation.
        Parameters:
        s - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitType

        R visitType​(TypeMirror t,
            P p)
        Visits a type value in an annotation.
        Parameters:
        t - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitEnumConstant

        R visitEnumConstant​(VariableElement c,
                    P p)
        Visits an enum value in an annotation.
        Parameters:
        c - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitAnnotation

        R visitAnnotation​(AnnotationMirror a,
                  P p)
        Visits an annotation value in an annotation.
        Parameters:
        a - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitArray

        R visitArray​(List<? extends AnnotationValue> vals,
             P p)
        Visits an array value in an annotation.
        Parameters:
        vals - the value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit

      • visitUnknown

        R visitUnknown​(AnnotationValue av,
               P p)
        Visits an unknown kind of annotation value. This can occur if the language evolves and new kinds of value can be stored in an annotation.
        Parameters:
        av - the unknown value being visited
        p - a visitor-specified parameter
        Returns:
        the result of the visit
        Throws:
        UnknownAnnotationValueException - a visitor implementation may optionally throw this exception