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*
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package javax.lang.model.element;
import java.util.List;
import javax.lang.model.type.TypeMirror;
/**
* Represents a module program element. Provides access to
* information about the module, its directives, and its members.
*
* @apiNote
* The represented module may have an explicit {@linkplain
* javax.lang.model.util.Elements#getFileObjectOf(Element) reference
* representation} (either source code or executable output) or may be
* created from implicit information. The explicit and standalone
* source code construct for a module is typically a {@code
* module-info.java} file (JLS {@jls 7.7}). {@linkplain
* javax.lang.model.util.Elements#isAutomaticModule(ModuleElement)
* Automatic modules} (JLS {@jls 7.7.1}) are named modules that do
* not have a {@code module-info} file. Implicit information
* is used to model {@linkplain #isUnnamed unnamed modules}.
* In the context of annotation processing, a module element can
* be:
*
* - created from the initial inputs to a run of the tool
*
- {@linkplain javax.lang.model.util.Elements#getModuleElement(CharSequence)
* queried for} in the configured environment
*
*
* @see javax.lang.model.util.Elements#getModuleOf
* @since 9
* @jls 7.7 Module Declarations
*/
public interface ModuleElement extends Element, QualifiedNameable {
/**
* {@return a {@linkplain javax.lang.model.type.NoType pseudo-type}
* for this module}
*
* @see javax.lang.model.type.NoType
* @see javax.lang.model.type.TypeKind#MODULE
*/
@Override
TypeMirror asType();
/**
* Returns the fully qualified name of this module. For an
* {@linkplain #isUnnamed() unnamed module}, an empty name is returned.
*
* @apiNote If the module name consists of one identifier, then
* this method returns that identifier, which is deemed to be
* module's fully qualified name despite not being in qualified
* form. If the module name consists of more than one identifier,
* then this method returns the entire name.
*
* @return the fully qualified name of this module, or an
* empty name if this is an unnamed module
*
* @jls 6.2 Names and Identifiers
*/
@Override
Name getQualifiedName();
/**
* Returns the simple name of this module. For an {@linkplain
* #isUnnamed() unnamed module}, an empty name is returned.
*
* @apiNote If the module name consists of one identifier, then
* this method returns that identifier. If the module name
* consists of more than one identifier, then this method returns
* the rightmost such identifier, which is deemed to be the
* module's simple name.
*
* @return the simple name of this module or an empty name if
* this is an unnamed module
*
* @jls 6.2 Names and Identifiers
*/
@Override
Name getSimpleName();
/**
* {@return the packages within this module}
*/
@Override
List getEnclosedElements();
/**
* {@return {@code true} if this is an open module and {@code
* false} otherwise}
*/
boolean isOpen();
/**
* {@return {@code true} if this is an unnamed module and {@code
* false} otherwise}
*
* @jls 7.7.5 Unnamed Modules
*/
boolean isUnnamed();
/**
* Returns {@code null} since a module is not enclosed by another
* element.
*
* @return {@code null}
*/
@Override
Element getEnclosingElement();
/**
* Returns the directives contained in the declaration of this module.
* @return the directives in the declaration of this module
*/
List getDirectives();
/**
* The {@code kind} of a directive.
*
* Note that it is possible additional directive kinds will be added
* to accommodate new, currently unknown, language structures added to
* future versions of the Java programming language.
*
* @since 9
*/
enum DirectiveKind {
/** A "requires (static|transitive)* module-name" directive. */
REQUIRES,
/** An "exports package-name [to module-name-list]" directive. */
EXPORTS,
/** An "opens package-name [to module-name-list]" directive. */
OPENS,
/** A "uses service-name" directive. */
USES,
/** A "provides service-name with implementation-name" directive. */
PROVIDES
};
/**
* Represents a directive within the declaration of this
* module. The directives of a module declaration configure the
* module in the Java Platform Module System.
*
* @since 9
*/
interface Directive {
/**
* {@return the {@code kind} of this directive}
*
*
* - The kind of a {@linkplain RequiresDirective requires
* directive} is {@link DirectiveKind#REQUIRES REQUIRES}.
*
*
- The kind of an {@linkplain ExportsDirective exports
* directive} is {@link DirectiveKind#EXPORTS EXPORTS}.
*
*
- The kind of an {@linkplain OpensDirective opens
* directive} is {@link DirectiveKind#OPENS OPENS}.
*
*
- The kind of a {@linkplain UsesDirective uses
* directive} is {@link DirectiveKind#USES USES}.
*
*
- The kind of a {@linkplain ProvidesDirective provides
* directive} is {@link DirectiveKind#PROVIDES PROVIDES}.
*
*
*/
DirectiveKind getKind();
/**
* Applies a visitor to this directive.
*
* @param the return type of the visitor's methods
* @param the type of the additional parameter to the visitor's methods
* @param v the visitor operating on this directive
* @param p additional parameter to the visitor
* @return a visitor-specified result
*/
R accept(DirectiveVisitor v, P p);
}
/**
* A visitor of module directives, in the style of the visitor design
* pattern. Classes implementing this interface are used to operate
* on a directive when the kind of directive is unknown at compile time.
* When a visitor is passed to a directive's {@link Directive#accept
* accept} method, the visitXyz method applicable
* to that directive is invoked.
*
* Classes implementing this interface may or may not throw a
* {@code NullPointerException} if the additional parameter {@code p}
* is {@code 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. Methods to accommodate new language constructs will
* be added in a source compatible way using
* default methods.
*
* @param the return type of this visitor's methods. Use {@link
* Void} for visitors that do not need to return results.
* @param the type of the additional parameter to this visitor's
* methods. Use {@code Void} for visitors that do not need an
* additional parameter.
*
* @since 9
*/
interface DirectiveVisitor {
/**
* Visits any directive as if by passing itself to that
* directive's {@link Directive#accept accept} method and passing
* {@code null} for the additional parameter.
*
* @param d the directive to visit
* @return a visitor-specified result
* @implSpec The default implementation is {@code d.accept(v, null)}.
*/
default R visit(Directive d) {
return d.accept(this, null);
}
/**
* Visits any directive as if by passing itself to that
* directive's {@link Directive#accept accept} method.
*
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
* @implSpec The default implementation is {@code d.accept(v, p)}.
*/
default R visit(Directive d, P p) {
return d.accept(this, p);
}
/**
* Visits a {@code requires} directive.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
*/
R visitRequires(RequiresDirective d, P p);
/**
* Visits an {@code exports} directive.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
*/
R visitExports(ExportsDirective d, P p);
/**
* Visits an {@code opens} directive.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
*/
R visitOpens(OpensDirective d, P p);
/**
* Visits a {@code uses} directive.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
*/
R visitUses(UsesDirective d, P p);
/**
* Visits a {@code provides} directive.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
*/
R visitProvides(ProvidesDirective d, P p);
/**
* Visits an unknown directive.
* This can occur if the language evolves and new kinds of directive are added.
* @param d the directive to visit
* @param p a visitor-specified parameter
* @return a visitor-specified result
* @throws UnknownDirectiveException a visitor implementation may optionally throw this exception
* @implSpec The default implementation throws {@code new UnknownDirectiveException(d, p)}.
*/
default R visitUnknown(Directive d, P p) {
throw new UnknownDirectiveException(d, p);
}
}
/**
* A dependency of a module.
* @since 9
*/
interface RequiresDirective extends Directive {
/**
* {@return whether or not this is a static dependency}
*/
boolean isStatic();
/**
* {@return whether or not this is a transitive dependency}
*/
boolean isTransitive();
/**
* {@return the module that is required}
*/
ModuleElement getDependency();
}
/**
* An exported package of a module.
* @since 9
*/
interface ExportsDirective extends Directive {
/**
* {@return the package being exported}
*/
PackageElement getPackage();
/**
* Returns the specific modules to which the package is being exported,
* or {@code null}, if the package is exported to all modules which
* have readability to this module.
* @return the specific modules to which the package is being exported
*/
List getTargetModules();
}
/**
* An opened package of a module.
* @since 9
*/
interface OpensDirective extends Directive {
/**
* {@return the package being opened}
*/
PackageElement getPackage();
/**
* Returns the specific modules to which the package is being open
* or {@code null}, if the package is open all modules which
* have readability to this module.
* @return the specific modules to which the package is being opened
*/
List getTargetModules();
}
/**
* An implementation of a service provided by a module.
* @since 9
*/
interface ProvidesDirective extends Directive {
/**
* {@return the service being provided}
*/
TypeElement getService();
/**
* {@return the implementations of the service being provided}
*/
List getImplementations();
}
/**
* A reference to a service used by a module.
* @since 9
*/
interface UsesDirective extends Directive {
/**
* {@return the service that is used}
*/
TypeElement getService();
}
}