1 /*
   2  * Copyright (c) 2005, 2017, 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 import javax.lang.model.util.*;
  31 
  32 /**
  33  * Represents a class or interface program element.  Provides access
  34  * to information about the type and its members.  Note that an enum
  35  * type is a kind of class and an annotation type is a kind of
  36  * interface.
  37  *
  38  * <p> While a {@code TypeElement} represents a class or interface
  39  * <i>element</i>, a {@link DeclaredType} represents a class
  40  * or interface <i>type</i>, the latter being a use
  41  * (or <i>invocation</i>) of the former.
  42  * The distinction is most apparent with generic types,
  43  * for which a single element can define a whole
  44  * family of types.  For example, the element
  45  * {@code java.util.Set} corresponds to the parameterized types
  46  * {@code java.util.Set<String>} and {@code java.util.Set<Number>}
  47  * (and many others), and to the raw type {@code java.util.Set}.
  48  *
  49  * <p> Each method of this interface that returns a list of elements
  50  * will return them in the order that is natural for the underlying
  51  * source of program information.  For example, if the underlying
  52  * source of information is Java source code, then the elements will be
  53  * returned in source code order.
  54  *
  55  * @author Joseph D. Darcy
  56  * @author Scott Seligman
  57  * @author Peter von der Ah&eacute;
  58  * @see DeclaredType
  59  * @since 1.6
  60  */
  61 public interface TypeElement extends Element, Parameterizable, QualifiedNameable {
  62     /**
  63      * Returns the fields, methods, constructors, and member types
  64      * that are directly declared in this class or interface.
  65      *
  66      * This includes any (implicit) default constructor and
  67      * the implicit {@code values} and {@code valueOf} methods of an
  68      * enum type.
  69      *
  70      * @apiNote As a particular instance of the {@linkplain
  71      * javax.lang.model.element general accuracy requirements} and the
  72      * ordering behavior required of this interface, the list of
  73      * enclosed elements will be returned in the natural order for the
  74      * originating source of information about the type.  For example,
  75      * if the information about the type is originating from a source
  76      * file, the elements will be returned in source code order.
  77      * (However, in that case the the ordering of {@linkplain Elements.Origin#MANDATED mandated}
  78      * elements, such as a default constructor, is not specified.)
  79      *
  80      * @return the enclosed elements in proper order, or an empty list if none
  81      */
  82     @Override
  83     List<? extends Element> getEnclosedElements();
  84 
  85     /**
  86      * Returns the <i>nesting kind</i> of this type element.
  87      *
  88      * @return the nesting kind of this type element
  89      */
  90     NestingKind getNestingKind();
  91 
  92     /**
  93      * Returns the fully qualified name of this type element.
  94      * More precisely, it returns the <i>canonical</i> name.
  95      * For local and anonymous classes, which do not have canonical names,
  96      * an empty name is returned.
  97      *
  98      * <p>The name of a generic type does not include any reference
  99      * to its formal type parameters.
 100      * For example, the fully qualified name of the interface
 101      * {@code java.util.Set<E>} is "{@code java.util.Set}".
 102      * Nested types use "{@code .}" as a separator, as in
 103      * "{@code java.util.Map.Entry}".
 104      *
 105      * @return the fully qualified name of this class or interface, or
 106      * an empty name if none
 107      *
 108      * @see Elements#getBinaryName
 109      * @jls 6.7 Fully Qualified Names and Canonical Names
 110      */
 111     Name getQualifiedName();
 112 
 113     /**
 114      * Returns the simple name of this type element.
 115      *
 116      * For an anonymous class, an empty name is returned.
 117      *
 118      * @return the simple name of this class or interface,
 119      * an empty name for an anonymous class
 120      *
 121      */
 122     @Override
 123     Name getSimpleName();
 124 
 125     /**
 126      * Returns the direct superclass of this type element.
 127      * If this type element represents an interface or the class
 128      * {@code java.lang.Object}, then a {@link NoType}
 129      * with kind {@link TypeKind#NONE NONE} is returned.
 130      *
 131      * @return the direct superclass, or a {@code NoType} if there is none
 132      */
 133     TypeMirror getSuperclass();
 134 
 135     /**
 136      * Returns the interface types directly implemented by this class
 137      * or extended by this interface.
 138      *
 139      * @return the interface types directly implemented by this class
 140      * or extended by this interface, or an empty list if there are none
 141      */
 142     List<? extends TypeMirror> getInterfaces();
 143 
 144     /**
 145      * Returns the formal type parameters of this type element
 146      * in declaration order.
 147      *
 148      * @return the formal type parameters, or an empty list
 149      * if there are none
 150      */
 151     List<? extends TypeParameterElement> getTypeParameters();
 152 
 153     /**
 154      * Returns the package of a top-level type and returns the
 155      * immediately lexically enclosing element for a {@linkplain
 156      * NestingKind#isNested nested} type.
 157      *
 158      * @return the package of a top-level type, the immediately
 159      * lexically enclosing element for a nested type
 160      */
 161     @Override
 162     Element getEnclosingElement();
 163 }