001package ball.annotation.processing;
002/*-
003 * ##########################################################################
004 * Utilities
005 * %%
006 * Copyright (C) 2008 - 2022 Allen D. Ball
007 * %%
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *      http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 * ##########################################################################
020 */
021import ball.annotation.ServiceProviderFor;
022import ball.util.ant.taskdefs.AntTask;
023import javax.annotation.processing.Processor;
024import javax.annotation.processing.RoundEnvironment;
025import javax.lang.model.element.AnnotationMirror;
026import javax.lang.model.element.AnnotationValue;
027import javax.lang.model.element.Element;
028import javax.lang.model.element.TypeElement;
029import lombok.NoArgsConstructor;
030import lombok.ToString;
031
032import static javax.tools.Diagnostic.Kind.ERROR;
033import static org.apache.commons.lang3.StringUtils.isEmpty;
034
035/**
036 * {@link Processor} implementation to check {@link Class}es annotated with
037 * {@link AntTask}:
038 * <ol>
039 *   <li value="1">Are an instance of {@link org.apache.tools.ant.Task},</li>
040 *   <li value="2">Concrete, and</li>
041 *   <li value="3">Have a public no-argument constructor</li>
042 * </ol>
043 *
044 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball}
045 */
046@ServiceProviderFor({ Processor.class })
047@For({ AntTask.class })
048@NoArgsConstructor @ToString
049public class AntTaskProcessor extends AnnotatedProcessor {
050    @Override
051    protected void process(RoundEnvironment roundEnv, TypeElement annotation, Element element) {
052        super.process(roundEnv, annotation, element);
053
054        AnnotationMirror mirror = getAnnotationMirror(element, annotation);
055        AnnotationValue value = getAnnotationValue(mirror, "value");
056
057        if (isEmpty((String) value.getValue())) {
058            print(ERROR, element, mirror, value, "value() must be non-empty");
059        }
060    }
061}