langtools/src/share/classes/javax/annotation/processing/AbstractProcessor.java
changeset 10 06bc494ca11e
child 5520 86e4b9a9da40
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/javax/annotation/processing/AbstractProcessor.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,195 @@
+/*
+ * Copyright 2005-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.annotation.processing;
+
+import java.util.Set;
+import java.util.HashSet;
+import java.util.Collections;
+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 annotations}, 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 Ah&eacute;
+ * @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.");
+        if (processingEnv == null)
+            throw new NullPointerException("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);
+    }
+}