Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2005, 2013, 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

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 package javax.annotation.processing;

 import java.util.Set;

 import java.util.HashSet;

 import java.util.Collections;

 import java.util.Objects;

 import javax.lang.model.element.*;

 import javax.lang.model.SourceVersion;

 import javax.tools.Diagnostic;

 /**

  * An abstract annotation processor designed to be a convenient

  * superclass for most concrete annotation processors.  This class

  * examines annotation values to compute the {@linkplain

  * #getSupportedOptions options}, {@linkplain

  * #getSupportedAnnotationTypes annotation types}, and {@linkplain

  * #getSupportedSourceVersion source version} supported by its

  * subtypes.

  *

  * <p>The getter methods may {@linkplain Messager#printMessage issue

  * warnings} about noteworthy conditions using the facilities available

  * after the processor has been {@linkplain #isInitialized

  * initialized}.

  *

  * <p>Subclasses are free to override the implementation and

  * specification of any of the methods in this class as long as the

  * general {@link javax.annotation.processing.Processor Processor}

  * contract for that method is obeyed.

  *

  * @author Joseph D. Darcy

  * @author Scott Seligman

  * @author Peter von der Ahé

  * @since 1.6

  */

 public abstract class AbstractProcessor implements Processor {

     /**

      * Processing environment providing by the tool framework.

      */

     protected ProcessingEnvironment processingEnv;

     private boolean initialized = false;

     /**

      * Constructor for subclasses to call.

      */

     protected AbstractProcessor() {}

     /**

      * If the processor class is annotated with {@link

      * SupportedOptions}, return an unmodifiable set with the same set

      * of strings as the annotation.  If the class is not so

      * annotated, an empty set is returned.

      *

      * @return the options recognized by this processor, or an empty

      * set if none

      */

     public Set<String> getSupportedOptions() {

         SupportedOptions so = this.getClass().getAnnotation(SupportedOptions.class);

         if  (so == null)

             return Collections.emptySet();

         else

             return arrayToSet(so.value());

     }

     /**

      * If the processor class is annotated with {@link

      * SupportedAnnotationTypes}, return an unmodifiable set with the

      * same set of strings as the annotation.  If the class is not so

      * annotated, an empty set is returned.

      *

      * @return the names of the annotation types supported by this

      * processor, or an empty set if none

      */

     public Set<String> getSupportedAnnotationTypes() {

             SupportedAnnotationTypes sat = this.getClass().getAnnotation(SupportedAnnotationTypes.class);

             if  (sat == null) {

                 if (isInitialized())

                     processingEnv.getMessager().printMessage(Diagnostic.Kind.WARNING,

                                                              "No SupportedAnnotationTypes annotation " +

                                                              "found on " + this.getClass().getName() +

                                                              ", returning an empty set.");

                 return Collections.emptySet();

             }

             else

                 return arrayToSet(sat.value());

         }

     /**

      * If the processor class is annotated with {@link

      * SupportedSourceVersion}, return the source version in the

      * annotation.  If the class is not so annotated, {@link

      * SourceVersion#RELEASE_6} is returned.

      *

      * @return the latest source version supported by this processor

      */

     public SourceVersion getSupportedSourceVersion() {

         SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class);

         SourceVersion sv = null;

         if (ssv == null) {

             sv = SourceVersion.RELEASE_6;

             if (isInitialized())

                 processingEnv.getMessager().printMessage(Diagnostic.Kind.WARNING,

                                                          "No SupportedSourceVersion annotation " +

                                                          "found on " + this.getClass().getName() +

                                                          ", returning " + sv + ".");

         } else

             sv = ssv.value();

         return sv;

     }

     /**

      * Initializes the processor with the processing environment by

      * setting the {@code processingEnv} field to the value of the

      * {@code processingEnv} argument.  An {@code

      * IllegalStateException} will be thrown if this method is called

      * more than once on the same object.

      *

      * @param processingEnv environment to access facilities the tool framework

      * provides to the processor

      * @throws IllegalStateException if this method is called more than once.

      */

     public synchronized void init(ProcessingEnvironment processingEnv) {

         if (initialized)

             throw new IllegalStateException("Cannot call init more than once.");

         Objects.requireNonNull(processingEnv, "Tool provided null ProcessingEnvironment");

         this.processingEnv = processingEnv;

         initialized = true;

     }

     /**

      * {@inheritDoc}

      */

     public abstract boolean process(Set<? extends TypeElement> annotations,

                                     RoundEnvironment roundEnv);

     /**

      * Returns an empty iterable of completions.

      *

      * @param element {@inheritDoc}

      * @param annotation {@inheritDoc}

      * @param member {@inheritDoc}

      * @param userText {@inheritDoc}

      */

     public Iterable<? extends Completion> getCompletions(Element element,

                                                          AnnotationMirror annotation,

                                                          ExecutableElement member,

                                                          String userText) {

         return Collections.emptyList();

     }

     /**

      * Returns {@code true} if this object has been {@linkplain #init

      * initialized}, {@code false} otherwise.

      *

      * @return {@code true} if this object has been initialized,

      * {@code false} otherwise.

      */

     protected synchronized boolean isInitialized() {

         return initialized;

     }

     private static Set<String> arrayToSet(String[] array) {

         assert array != null;

         Set<String> set = new HashSet<String>(array.length);

         for (String s : array)

             set.add(s);

         return Collections.unmodifiableSet(set);

     }

 }