| 1 | /* |
| 2 | * Copyright 2005-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.annotation.processing; |
| 27 | |
| 28 | import java.util.Set; |
| 29 | import java.util.HashSet; |
| 30 | import java.util.Collections; |
| 31 | import javax.lang.model.element.*; |
| 32 | import javax.lang.model.SourceVersion; |
| 33 | import javax.tools.Diagnostic; |
| 34 | |
| 35 | /** |
| 36 | * An abstract annotation processor designed to be a convenient |
| 37 | * superclass for most concrete annotation processors. This class |
| 38 | * examines annotation values to compute the {@linkplain |
| 39 | * #getSupportedOptions options}, {@linkplain |
| 40 | * #getSupportedAnnotationTypes annotations}, and {@linkplain |
| 41 | * #getSupportedSourceVersion source version} supported by its |
| 42 | * subtypes. |
| 43 | * |
| 44 | * <p>The getter methods may {@linkplain Messager#printMessage issue |
| 45 | * warnings} about noteworthy conditions using the facilities available |
| 46 | * after the processor has been {@linkplain #isInitialized |
| 47 | * initialized}. |
| 48 | * |
| 49 | * <p>Subclasses are free to override the implementation and |
| 50 | * specification of any of the methods in this class as long as the |
| 51 | * general {@link javax.annotation.processing.Processor Processor} |
| 52 | * contract for that method is obeyed. |
| 53 | * |
| 54 | * @author Joseph D. Darcy |
| 55 | * @author Scott Seligman |
| 56 | * @author Peter von der Ahé |
| 57 | * @since 1.6 |
| 58 | */ |
| 59 | public abstract class AbstractProcessor implements Processor { |
| 60 | /** |
| 61 | * Processing environment providing by the tool framework. |
| 62 | */ |
| 63 | protected ProcessingEnvironment processingEnv; |
| 64 | private boolean initialized = false; |
| 65 | |
| 66 | /** |
| 67 | * Constructor for subclasses to call. |
| 68 | */ |
| 69 | protected AbstractProcessor() {} |
| 70 | |
| 71 | /** |
| 72 | * If the processor class is annotated with {@link |
| 73 | * SupportedOptions}, return an unmodifiable set with the same set |
| 74 | * of strings as the annotation. If the class is not so |
| 75 | * annotated, an empty set is returned. |
| 76 | * |
| 77 | * @return the options recognized by this processor, or an empty |
| 78 | * set if none |
| 79 | */ |
| 80 | public Set<String> getSupportedOptions() { |
| 81 | SupportedOptions so = this.getClass().getAnnotation(SupportedOptions.class); |
| 82 | if (so == null) |
| 83 | return Collections.emptySet(); |
| 84 | else |
| 85 | return arrayToSet(so.value()); |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * If the processor class is annotated with {@link |
| 90 | * SupportedAnnotationTypes}, return an unmodifiable set with the |
| 91 | * same set of strings as the annotation. If the class is not so |
| 92 | * annotated, an empty set is returned. |
| 93 | * |
| 94 | * @return the names of the annotation types supported by this |
| 95 | * processor, or an empty set if none |
| 96 | */ |
| 97 | public Set<String> getSupportedAnnotationTypes() { |
| 98 | SupportedAnnotationTypes sat = this.getClass().getAnnotation(SupportedAnnotationTypes.class); |
| 99 | if (sat == null) { |
| 100 | if (isInitialized()) |
| 101 | processingEnv.getMessager().printMessage(Diagnostic.Kind.WARNING, |
| 102 | "No SupportedAnnotationTypes annotation " + |
| 103 | "found on " + this.getClass().getName() + |
| 104 | ", returning an empty set."); |
| 105 | return Collections.emptySet(); |
| 106 | } |
| 107 | else |
| 108 | return arrayToSet(sat.value()); |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * If the processor class is annotated with {@link |
| 113 | * SupportedSourceVersion}, return the source version in the |
| 114 | * annotation. If the class is not so annotated, {@link |
| 115 | * SourceVersion#RELEASE_6} is returned. |
| 116 | * |
| 117 | * @return the latest source version supported by this processor |
| 118 | */ |
| 119 | public SourceVersion getSupportedSourceVersion() { |
| 120 | SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class); |
| 121 | SourceVersion sv = null; |
| 122 | if (ssv == null) { |
| 123 | sv = SourceVersion.RELEASE_6; |
| 124 | if (isInitialized()) |
| 125 | processingEnv.getMessager().printMessage(Diagnostic.Kind.WARNING, |
| 126 | "No SupportedSourceVersion annotation " + |
| 127 | "found on " + this.getClass().getName() + |
| 128 | ", returning " + sv + "."); |
| 129 | } else |
| 130 | sv = ssv.value(); |
| 131 | return sv; |
| 132 | } |
| 133 | |
| 134 | |
| 135 | /** |
| 136 | * Initializes the processor with the processing environment by |
| 137 | * setting the {@code processingEnv} field to the value of the |
| 138 | * {@code processingEnv} argument. An {@code |
| 139 | * IllegalStateException} will be thrown if this method is called |
| 140 | * more than once on the same object. |
| 141 | * |
| 142 | * @param processingEnv environment to access facilities the tool framework |
| 143 | * provides to the processor |
| 144 | * @throws IllegalStateException if this method is called more than once. |
| 145 | */ |
| 146 | public synchronized void init(ProcessingEnvironment processingEnv) { |
| 147 | if (initialized) |
| 148 | throw new IllegalStateException("Cannot call init more than once."); |
| 149 | if (processingEnv == null) |
| 150 | throw new NullPointerException("Tool provided null ProcessingEnvironment"); |
| 151 | |
| 152 | this.processingEnv = processingEnv; |
| 153 | initialized = true; |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * {@inheritDoc} |
| 158 | */ |
| 159 | public abstract boolean process(Set<? extends TypeElement> annotations, |
| 160 | RoundEnvironment roundEnv); |
| 161 | |
| 162 | /** |
| 163 | * Returns an empty iterable of completions. |
| 164 | * |
| 165 | * @param element {@inheritDoc} |
| 166 | * @param annotation {@inheritDoc} |
| 167 | * @param member {@inheritDoc} |
| 168 | * @param userText {@inheritDoc} |
| 169 | */ |
| 170 | public Iterable<? extends Completion> getCompletions(Element element, |
| 171 | AnnotationMirror annotation, |
| 172 | ExecutableElement member, |
| 173 | String userText) { |
| 174 | return Collections.emptyList(); |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Returns {@code true} if this object has been {@linkplain #init |
| 179 | * initialized}, {@code false} otherwise. |
| 180 | * |
| 181 | * @return {@code true} if this object has been initialized, |
| 182 | * {@code false} otherwise. |
| 183 | */ |
| 184 | protected synchronized boolean isInitialized() { |
| 185 | return initialized; |
| 186 | } |
| 187 | |
| 188 | private static Set<String> arrayToSet(String[] array) { |
| 189 | assert array != null; |
| 190 | Set<String> set = new HashSet<String>(array.length); |
| 191 | for (String s : array) |
| 192 | set.add(s); |
| 193 | return Collections.unmodifiableSet(set); |
| 194 | } |
| 195 | } |