src/java.compiler/share/classes/javax/lang/model/element/ExecutableElement.java

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package javax.lang.model.element;

import java.util.List;
import javax.lang.model.type.*;

/**
 * Represents a method, constructor, or initializer (static or
 * instance) of a class or interface, including annotation interface
 * elements.
 * Annotation interface elements are methods restricted to have no
 * formal parameters, no type parameters, and no {@code throws}
 * clause, among other restrictions; see JLS {@jls 9.6.1} for details.
 *
 * @see ExecutableType
 * @since 1.6
 */
public interface ExecutableElement extends Element, Parameterizable {
    /**
     * {@return the {@linkplain ExecutableType executable type} defined
     * by this executable element}
     *
     * @see ExecutableType
     */
    @Override
    TypeMirror asType();

    /**
     * Returns the formal type parameters of this executable
     * in declaration order.
     *
     * @return the formal type parameters, or an empty list
     * if there are none
     */
    List<? extends TypeParameterElement> getTypeParameters();

    /**
     * {@return the return type of this executable}
     * Returns a {@link NoType} with kind {@link TypeKind#VOID VOID}
     * if this executable is not a method, or is a method that does not
     * return a value.
     */
    TypeMirror getReturnType();

    /**
     * Returns the formal parameters of this executable.
     * They are returned in declaration order.
     *
     * @return the formal parameters,
     * or an empty list if there are none
     */
    List<? extends VariableElement> getParameters();

    /**
     * Returns the receiver type of this executable,
     * or {@link javax.lang.model.type.NoType NoType} with
     * kind {@link javax.lang.model.type.TypeKind#NONE NONE}
     * if the executable has no receiver type.
     *
     * An executable which is an instance method, or a constructor of an
     * inner class, has a receiver type derived from the {@linkplain
     * #getEnclosingElement declaring type}.
     *
     * An executable which is a static method, or a constructor of a
     * non-inner class, or an initializer (static or instance), has no
     * receiver type.
     *
     * <p>The receiver <em>parameter</em> is a syntactic device added
     * to the language for the purpose of hosting annotations. Even
     * when source code is used as the basis for creating an
     * executable, if a receiver parameter is not present in the
     * source code, an implementation may elect to return a {@code
     * NoType} object even in cases where a receiver <em>type</em> is
     * nominally defined on the executable in question, such as an
     * instance method.  When a receiver parameter is present and
     * hosting annotations, a suitably annotated receiver type is
     * returned.
     *
     * @return the receiver type of this executable
     * @since 1.8
     *
     * @jls 8.4 Method Declarations
     * @jls 8.4.1 Formal Parameters
     * @jls 8.8 Constructor Declarations
     */
    TypeMirror getReceiverType();

    /**
     * {@return {@code true} if this method or constructor accepts a variable
     * number of arguments and returns {@code false} otherwise}
     */
    boolean isVarArgs();

    /**
     * {@return {@code true} if this method is a default method and
     * returns {@code false} otherwise}
     * @since 1.8
     */
    boolean isDefault();

    /**
     * Returns the exceptions and other throwables listed in this
     * method or constructor's {@code throws} clause in declaration
     * order.
     *
     * @return the exceptions and other throwables listed in the
     * {@code throws} clause, or an empty list if there are none
     */
    List<? extends TypeMirror> getThrownTypes();

    /**
     * Returns the default value if this executable is an annotation
     * interface element.  Returns {@code null} if this method is not
     * an annotation interface element, or if it is an annotation
     * interface element with no default value.
     *
     * @return the default value, or {@code null} if none
     */
    AnnotationValue getDefaultValue();

    /**
     * {@return the class or interface defining the executable}
     */
    @Override
    Element getEnclosingElement();

    /**
     * {@return the simple name of a constructor, method, or
     * initializer}  For a constructor, the name {@code "<init>"} is
     * returned, for a static initializer, the name {@code "<clinit>"}
     * is returned, and for an anonymous class or instance
     * initializer, an {@linkplain Name##empty_name empty name} is
     * returned.
     */
    @Override
    Name getSimpleName();
}