| /* |
| * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.lang.model.util; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.EnumSet; |
| import java.util.ArrayList; |
| import java.util.LinkedHashSet; |
| |
| import javax.lang.model.element.*; |
| import javax.lang.model.element.ModuleElement.Directive; |
| import javax.lang.model.element.ModuleElement.DirectiveKind; |
| import javax.lang.model.element.ModuleElement.ExportsDirective; |
| import javax.lang.model.element.ModuleElement.OpensDirective; |
| import javax.lang.model.element.ModuleElement.ProvidesDirective; |
| import javax.lang.model.element.ModuleElement.RequiresDirective; |
| import javax.lang.model.element.ModuleElement.UsesDirective; |
| |
| |
| /** |
| * Filters for selecting just the elements of interest from a |
| * collection of elements. The returned sets and lists are new |
| * collections and do use the argument as a backing store. The |
| * methods in this class do not make any attempts to guard against |
| * concurrent modifications of the arguments. The returned sets and |
| * lists are mutable but unsafe for concurrent access. A returned set |
| * has the same iteration order as the argument set to a method. |
| * |
| * <p>If iterables and sets containing {@code null} are passed as |
| * arguments to methods in this class, a {@code NullPointerException} |
| * will be thrown. |
| * |
| * @author Joseph D. Darcy |
| * @author Scott Seligman |
| * @author Peter von der Ahé |
| * @author Martin Buchholz |
| * @since 1.6 |
| */ |
| public class ElementFilter { |
| private ElementFilter() {} // Do not instantiate. |
| |
| private static final Set<ElementKind> CONSTRUCTOR_KIND = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.CONSTRUCTOR)); |
| |
| private static final Set<ElementKind> FIELD_KINDS = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.FIELD, |
| ElementKind.ENUM_CONSTANT)); |
| private static final Set<ElementKind> METHOD_KIND = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.METHOD)); |
| |
| private static final Set<ElementKind> PACKAGE_KIND = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.PACKAGE)); |
| |
| private static final Set<ElementKind> MODULE_KIND = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.MODULE)); |
| |
| private static final Set<ElementKind> TYPE_KINDS = |
| Collections.unmodifiableSet(EnumSet.of(ElementKind.CLASS, |
| ElementKind.ENUM, |
| ElementKind.INTERFACE, |
| ElementKind.ANNOTATION_TYPE)); |
| /** |
| * Returns a list of fields in {@code elements}. |
| * @return a list of fields in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static List<VariableElement> |
| fieldsIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, FIELD_KINDS, VariableElement.class); |
| } |
| |
| /** |
| * Returns a set of fields in {@code elements}. |
| * @return a set of fields in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static Set<VariableElement> |
| fieldsIn(Set<? extends Element> elements) { |
| return setFilter(elements, FIELD_KINDS, VariableElement.class); |
| } |
| |
| /** |
| * Returns a list of constructors in {@code elements}. |
| * @return a list of constructors in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static List<ExecutableElement> |
| constructorsIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, CONSTRUCTOR_KIND, ExecutableElement.class); |
| } |
| |
| /** |
| * Returns a set of constructors in {@code elements}. |
| * @return a set of constructors in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static Set<ExecutableElement> |
| constructorsIn(Set<? extends Element> elements) { |
| return setFilter(elements, CONSTRUCTOR_KIND, ExecutableElement.class); |
| } |
| |
| /** |
| * Returns a list of methods in {@code elements}. |
| * @return a list of methods in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static List<ExecutableElement> |
| methodsIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, METHOD_KIND, ExecutableElement.class); |
| } |
| |
| /** |
| * Returns a set of methods in {@code elements}. |
| * @return a set of methods in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static Set<ExecutableElement> |
| methodsIn(Set<? extends Element> elements) { |
| return setFilter(elements, METHOD_KIND, ExecutableElement.class); |
| } |
| |
| /** |
| * Returns a list of types in {@code elements}. |
| * @return a list of types in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static List<TypeElement> |
| typesIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, TYPE_KINDS, TypeElement.class); |
| } |
| |
| /** |
| * Returns a set of types in {@code elements}. |
| * @return a set of types in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static Set<TypeElement> |
| typesIn(Set<? extends Element> elements) { |
| return setFilter(elements, TYPE_KINDS, TypeElement.class); |
| } |
| |
| /** |
| * Returns a list of packages in {@code elements}. |
| * @return a list of packages in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static List<PackageElement> |
| packagesIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, PACKAGE_KIND, PackageElement.class); |
| } |
| |
| /** |
| * Returns a set of packages in {@code elements}. |
| * @return a set of packages in {@code elements} |
| * @param elements the elements to filter |
| */ |
| public static Set<PackageElement> |
| packagesIn(Set<? extends Element> elements) { |
| return setFilter(elements, PACKAGE_KIND, PackageElement.class); |
| } |
| |
| /** |
| * Returns a list of modules in {@code elements}. |
| * @return a list of modules in {@code elements} |
| * @param elements the elements to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static List<ModuleElement> |
| modulesIn(Iterable<? extends Element> elements) { |
| return listFilter(elements, MODULE_KIND, ModuleElement.class); |
| } |
| |
| /** |
| * Returns a set of modules in {@code elements}. |
| * @return a set of modules in {@code elements} |
| * @param elements the elements to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static Set<ModuleElement> |
| modulesIn(Set<? extends Element> elements) { |
| return setFilter(elements, MODULE_KIND, ModuleElement.class); |
| } |
| |
| // Assumes targetKinds and E are sensible. |
| private static <E extends Element> List<E> listFilter(Iterable<? extends Element> elements, |
| Set<ElementKind> targetKinds, |
| Class<E> clazz) { |
| List<E> list = new ArrayList<>(); |
| for (Element e : elements) { |
| if (targetKinds.contains(e.getKind())) |
| list.add(clazz.cast(e)); |
| } |
| return list; |
| } |
| |
| // Assumes targetKinds and E are sensible. |
| private static <E extends Element> Set<E> setFilter(Set<? extends Element> elements, |
| Set<ElementKind> targetKinds, |
| Class<E> clazz) { |
| // Return set preserving iteration order of input set. |
| Set<E> set = new LinkedHashSet<>(); |
| for (Element e : elements) { |
| if (targetKinds.contains(e.getKind())) |
| set.add(clazz.cast(e)); |
| } |
| return set; |
| } |
| |
| /** |
| * Returns a list of {@code exports} directives in {@code directives}. |
| * @return a list of {@code exports} directives in {@code directives} |
| * @param directives the directives to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static List<ExportsDirective> |
| exportsIn(Iterable<? extends Directive> directives) { |
| return listFilter(directives, DirectiveKind.EXPORTS, ExportsDirective.class); |
| } |
| |
| /** |
| * Returns a list of {@code opens} directives in {@code directives}. |
| * @return a list of {@code opens} directives in {@code directives} |
| * @param directives the directives to filter |
| * @since 9 |
| */ |
| public static List<OpensDirective> |
| opensIn(Iterable<? extends Directive> directives) { |
| return listFilter(directives, DirectiveKind.OPENS, OpensDirective.class); |
| } |
| |
| /** |
| * Returns a list of {@code provides} directives in {@code directives}. |
| * @return a list of {@code provides} directives in {@code directives} |
| * @param directives the directives to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static List<ProvidesDirective> |
| providesIn(Iterable<? extends Directive> directives) { |
| return listFilter(directives, DirectiveKind.PROVIDES, ProvidesDirective.class); |
| } |
| |
| /** |
| * Returns a list of {@code requires} directives in {@code directives}. |
| * @return a list of {@code requires} directives in {@code directives} |
| * @param directives the directives to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static List<RequiresDirective> |
| requiresIn(Iterable<? extends Directive> directives) { |
| return listFilter(directives, DirectiveKind.REQUIRES, RequiresDirective.class); |
| } |
| |
| /** |
| * Returns a list of {@code uses} directives in {@code directives}. |
| * @return a list of {@code uses} directives in {@code directives} |
| * @param directives the directives to filter |
| * @since 9 |
| * @spec JPMS |
| */ |
| public static List<UsesDirective> |
| usesIn(Iterable<? extends Directive> directives) { |
| return listFilter(directives, DirectiveKind.USES, UsesDirective.class); |
| } |
| |
| // Assumes directiveKind and D are sensible. |
| private static <D extends Directive> List<D> listFilter(Iterable<? extends Directive> directives, |
| DirectiveKind directiveKind, |
| Class<D> clazz) { |
| List<D> list = new ArrayList<>(); |
| for (Directive d : directives) { |
| if (d.getKind() == directiveKind) |
| list.add(clazz.cast(d)); |
| } |
| return list; |
| } |
| } |
