| // |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
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| // |
| |
| = DevFaqScanForClasses |
| :jbake-type: wiki |
| :jbake-tags: wiki, devfaq, needsreview |
| :jbake-status: published |
| :keywords: Apache NetBeans wiki DevFaqScanForClasses |
| :description: Apache NetBeans wiki DevFaqScanForClasses |
| :toc: left |
| :toc-title: |
| :syntax: true |
| |
| === How can I scan a classpath to find all classes of a particular type? |
| |
| ==== Prerequisites |
| |
| * find the ClassPath on which the subtypes should be found. Use e.g. ClassPath.getClassPath(<file>, ClassPath.SOURCE) |
| * if the supertype is given as a FQN, convert to ElementHandle<TypeElement> via ElementHandle.create inside a Task or CancellableTask. |
| |
| ==== Finding all subtypes of given type |
| |
| All subtypes of a given type on a given ClassPath can be found using ClassIndex. As ClassIndex contains only direct subtypes, the indirect subtypes need to be found on the client side: |
| |
| [source,java] |
| ---- |
| |
| private Set<ElementHandle<TypeElement>> findAllSubTypes(ClassPath on, ElementHandle<TypeElement> of) { |
| ClasspathInfo cpInfo = ClasspathInfo.create(ClassPath.EMPTY, ClassPath.EMPTY, on); |
| |
| List<ElementHandle<TypeElement>> todo = new LinkedList<ElementHandle<TypeElement>>(of); |
| Set<ElementHandle<TypeElement>> result = new HashSet<ElementHandle<TypeElement>>(); |
| |
| while (!todo.isEmpty()) { |
| //TODO: if cancellable, check for cancel here |
| |
| ElementHandle<TypeElement> curr = todo.remove(0); |
| |
| result.add(curr); |
| |
| Set<ElementHandle<TypeElement>> typeElements = cpInfo.getClassIndex().getElements(eh, EnumSet.of(ClassIndex.SearchKind.IMPLEMENTORS), EnumSet.of(ClassIndex.SearchScope.SOURCE)); |
| |
| if (typeElements != null) { //can be null for cancellable tasks |
| todo.addAll(typeElements); |
| } |
| } |
| |
| return result; |
| } |
| ---- |
| |
| ==== Getting FileObjects corresponding to ElementHandles |
| |
| The FileObject corresponding to a given ElementHandle<TypeElement> can be found using SourceUtils.getFile. |
| |
| === Apache Migration Information |
| |
| The content in this page was kindly donated by Oracle Corp. to the |
| Apache Software Foundation. |
| |
| This page was exported from link:http://wiki.netbeans.org/DevFaqScanForClasses[http://wiki.netbeans.org/DevFaqScanForClasses] , |
| that was last modified by NetBeans user Jlahoda |
| on 2011-12-15T08:29:15Z. |
| |
| |
| *NOTE:* This document was automatically converted to the AsciiDoc format on 2018-02-07, and needs to be reviewed. |