1 /*
   2  * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.lang.model.element;
  27 
  28 import java.util.List;
  29 import javax.lang.model.type.*;
  30 
  31 /**
  32  * Represents a method, constructor, or initializer (static or
  33  * instance) of a class or interface, including annotation type
  34  * elements.
  35  *
  36  * @author Joseph D. Darcy
  37  * @author Scott Seligman
  38  * @author Peter von der Ahé
  39  * @see ExecutableType
  40  * @since 1.6
  41  */
  42 public interface ExecutableElement extends Element, Parameterizable {
  43     /**
  44      * Returns the {@linkplain ExecutableType executable type} defined
  45      * by this executable element.
  46      *
  47      * @return the executable type defined by this executable element
  48      *
  49      * @see ExecutableType
  50      */
  51     @Override
  52     TypeMirror asType();
  53 
  54     /**
  55      * Returns the formal type parameters of this executable
  56      * in declaration order.
  57      *
  58      * @return the formal type parameters, or an empty list
  59      * if there are none
  60      */
  61     List<? extends TypeParameterElement> getTypeParameters();
  62 
  63     /**
  64      * Returns the return type of this executable.
  65      * Returns a {@link NoType} with kind {@link TypeKind#VOID VOID}
  66      * if this executable is not a method, or is a method that does not
  67      * return a value.
  68      *
  69      * @return the return type of this executable
  70      */
  71     TypeMirror getReturnType();
  72 
  73     /**
  74      * Returns the formal parameters of this executable.
  75      * They are returned in declaration order.
  76      *
  77      * @return the formal parameters,
  78      * or an empty list if there are none
  79      */
  80     List<? extends VariableElement> getParameters();
  81 
  82     /**
  83      * Returns the receiver type of this executable,
  84      * or {@link javax.lang.model.type.NoType NoType} with
  85      * kind {@link javax.lang.model.type.TypeKind#NONE NONE}
  86      * if the executable has no receiver type.
  87      *
  88      * An executable which is an instance method, or a constructor of an
  89      * inner class, has a receiver type derived from the {@linkplain
  90      * #getEnclosingElement declaring type}.
  91      *
  92      * An executable which is a static method, or a constructor of a
  93      * non-inner class, or an initializer (static or instance), has no
  94      * receiver type.
  95      *
  96      * @return the receiver type of this executable
  97      * @since 1.8
  98      *
  99      * @jls 8.4 Method Declarations
 100      * @jls 8.4.1 Formal Parameters
 101      * @jls 8.8 Constructor Declarations
 102      */
 103     TypeMirror getReceiverType();
 104 
 105     /**
 106      * Returns {@code true} if this method or constructor accepts a variable
 107      * number of arguments and returns {@code false} otherwise.
 108      *
 109      * @return {@code true} if this method or constructor accepts a variable
 110      * number of arguments and {@code false} otherwise
 111      */
 112     boolean isVarArgs();
 113 
 114     /**
 115      * Returns {@code true} if this method is a default method and
 116      * returns {@code false} otherwise.
 117      *
 118      * @return {@code true} if this method is a default method and
 119      * {@code false} otherwise
 120      * @since 1.8
 121      */
 122     boolean isDefault();
 123 
 124     /**
 125      * Returns the exceptions and other throwables listed in this
 126      * method or constructor's {@code throws} clause in declaration
 127      * order.
 128      *
 129      * @return the exceptions and other throwables listed in the
 130      * {@code throws} clause, or an empty list if there are none
 131      */
 132     List<? extends TypeMirror> getThrownTypes();
 133 
 134     /**
 135      * Returns the default value if this executable is an annotation
 136      * type element.  Returns {@code null} if this method is not an
 137      * annotation type element, or if it is an annotation type element
 138      * with no default value.
 139      *
 140      * @return the default value, or {@code null} if none
 141      */
 142     AnnotationValue getDefaultValue();
 143 
 144     /**
 145      * Returns the simple name of a constructor, method, or
 146      * initializer.  For a constructor, the name {@code "<init>"} is
 147      * returned, for a static initializer, the name {@code "<clinit>"}
 148      * is returned, and for an anonymous class or instance
 149      * initializer, an empty name is returned.
 150      *
 151      * @return the simple name of a constructor, method, or
 152      * initializer
 153      */
 154     @Override
 155     Name getSimpleName();
 156 }