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 
  30 /**
  31  * Represents a package program element.  Provides access to information
  32  * about the package and its members.
  33  *
  34  * @author Joseph D. Darcy
  35  * @author Scott Seligman
  36  * @author Peter von der Ahé
  37  * @see javax.lang.model.util.Elements#getPackageOf
  38  * @since 1.6
  39  */
  40 public interface PackageElement extends Element, QualifiedNameable {
  41 
  42     /**
  43      * Returns the fully qualified name of this package.
  44      * This is also known as the package's <i>canonical</i> name.
  45      * For an {@linkplain #isUnnamed() unnamed package}, an empty name is returned.
  46      *
  47      * @apiNote The fully qualified name of a named package that is
  48      * not a subpackage of a named package is its simple name. The
  49      * fully qualified name of a named package that is a subpackage of
  50      * another named package consists of the fully qualified name of
  51      * the containing package, followed by "{@code .}", followed by the simple
  52      * (member) name of the subpackage.
  53      *
  54      * @return the fully qualified name of this package, or an
  55      * empty name if this is an unnamed package
  56      * @jls 6.7 Fully Qualified Names and Canonical Names
  57      */
  58     Name getQualifiedName();
  59 
  60     /**
  61      * Returns the simple name of this package.  For an {@linkplain
  62      * #isUnnamed() unnamed package}, an empty name is returned.
  63      *
  64      * @return the simple name of this package or an empty name if
  65      * this is an unnamed package
  66      */
  67     @Override
  68     Name getSimpleName();
  69 
  70     /**
  71      * Returns the {@linkplain NestingKind#TOP_LEVEL top-level}
  72      * classes and interfaces within this package.  Note that
  73      * subpackages are <em>not</em> considered to be enclosed by a
  74      * package.
  75      *
  76      * @return the top-level classes and interfaces within this
  77      * package
  78      */
  79     @Override
  80     List<? extends Element> getEnclosedElements();
  81 
  82     /**
  83      * Returns {@code true} if this is an unnamed package and {@code
  84      * false} otherwise.
  85      *
  86      * @return {@code true} if this is an unnamed package and {@code
  87      * false} otherwise
  88      * @jls 7.4.2 Unnamed Packages
  89      */
  90     boolean isUnnamed();
  91 
  92     /**
  93      * Returns the enclosing module if such a module exists; otherwise
  94      * returns {@code null}.
  95      *
  96      * One situation where a module does not exist for a package is if
  97      * the environment does not include modules, such as an annotation
  98      * processing environment configured for a {@linkplain
  99      * javax.annotation.processing.ProcessingEnvironment#getSourceVersion
 100      * source version} without modules.
 101      *
 102      * @return the enclosing module or {@code null} if no such module exists
 103      *
 104      * @revised 9
 105      * @spec JPMS
 106      */
 107     @Override
 108     Element getEnclosingElement();
 109 }