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.TypeMirror;
  30 
  31 /**
  32  * Represents a package program element.  Provides access to information
  33  * about the package and its members.
  34  *
  35  * @author Joseph D. Darcy
  36  * @author Scott Seligman
  37  * @author Peter von der Ahé
  38  * @see javax.lang.model.util.Elements#getPackageOf
  39  * @since 1.6
  40  */
  41 public interface PackageElement extends Element, QualifiedNameable {
  42     /**
  43      * Returns a {@linkplain javax.lang.model.type.NoType pseudo-type} for this package.
  44      * @return a pseudo-type for this package
  45      */
  46     @Override
  47     TypeMirror asType();
  48 
  49     /**
  50      * Returns the fully qualified name of this package.
  51      * This is also known as the package's <i>canonical</i> name.
  52      * For an {@linkplain #isUnnamed() unnamed package}, an empty name is returned.
  53      *
  54      * @apiNote The fully qualified name of a named package that is
  55      * not a subpackage of a named package is its simple name. The
  56      * fully qualified name of a named package that is a subpackage of
  57      * another named package consists of the fully qualified name of
  58      * the containing package, followed by "{@code .}", followed by the simple
  59      * (member) name of the subpackage.
  60      *
  61      * @return the fully qualified name of this package, or an
  62      * empty name if this is an unnamed package
  63      * @jls 6.7 Fully Qualified Names and Canonical Names
  64      */
  65     Name getQualifiedName();
  66 
  67     /**
  68      * Returns the simple name of this package.  For an {@linkplain
  69      * #isUnnamed() unnamed package}, an empty name is returned.
  70      *
  71      * @return the simple name of this package or an empty name if
  72      * this is an unnamed package
  73      */
  74     @Override
  75     Name getSimpleName();
  76 
  77     /**
  78      * Returns the {@linkplain NestingKind#TOP_LEVEL top-level}
  79      * classes and interfaces within this package.  Note that
  80      * subpackages are <em>not</em> considered to be enclosed by a
  81      * package.
  82      *
  83      * @return the top-level classes and interfaces within this
  84      * package
  85      */
  86     @Override
  87     List<? extends Element> getEnclosedElements();
  88 
  89     /**
  90      * Returns {@code true} if this is an unnamed package and {@code
  91      * false} otherwise.
  92      *
  93      * @return {@code true} if this is an unnamed package and {@code
  94      * false} otherwise
  95      * @jls 7.4.2 Unnamed Packages
  96      */
  97     boolean isUnnamed();
  98 
  99     /**
 100      * Returns the enclosing module if such a module exists; otherwise
 101      * returns {@code null}.
 102      *
 103      * One situation where a module does not exist for a package is if
 104      * the environment does not include modules, such as an annotation
 105      * processing environment configured for a {@linkplain
 106      * javax.annotation.processing.ProcessingEnvironment#getSourceVersion
 107      * source version} without modules.
 108      *
 109      * @return the enclosing module or {@code null} if no such module exists
 110      *
 111      * @revised 9
 112      * @spec JPMS
 113      */
 114     @Override
 115     Element getEnclosingElement();
 116 }