001package ball.util.ant.taskdefs;
002/*-
003 * ##########################################################################
004 * Utilities
005 * $Id: NotNull.html 5431 2020-02-12 19:03:17Z ball $
006 * $HeadURL: svn+ssh://svn.hcf.dev/var/spool/scm/repository.svn/hcf-dev/blog/2019-07-08-fivethirtyeight-best-scrabble-string/src/main/resources/javadoc/src-html/ball/util/ant/taskdefs/NotNull.html $
007 * %%
008 * Copyright (C) 2008 - 2020 Allen D. Ball
009 * %%
010 * Licensed under the Apache License, Version 2.0 (the "License");
011 * you may not use this file except in compliance with the License.
012 * You may obtain a copy of the License at
013 *
014 *      http://www.apache.org/licenses/LICENSE-2.0
015 *
016 * Unless required by applicable law or agreed to in writing, software
017 * distributed under the License is distributed on an "AS IS" BASIS,
018 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
019 * See the License for the specific language governing permissions and
020 * limitations under the License.
021 * ##########################################################################
022 */
023import java.lang.annotation.Documented;
024import java.lang.annotation.Retention;
025import java.lang.annotation.Target;
026import lombok.NoArgsConstructor;
027import lombok.ToString;
028import org.apache.tools.ant.Task;
029import org.apache.tools.ant.TaskConfigurationChecker;
030
031import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
032import static java.lang.annotation.ElementType.FIELD;
033import static java.lang.annotation.ElementType.METHOD;
034import static java.lang.annotation.RetentionPolicy.RUNTIME;
035
036/**
037 * {@link AntTaskAttributeConstraint} annotation to indicate that an
038 * attribute cannot be {@code null}.
039 *
040 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball}
041 * @version $Revision: 5431 $
042 */
043@AntTaskAttributeConstraint(NotNull.Checker.class)
044@Documented
045@Retention(RUNTIME)
046@Target({ ANNOTATION_TYPE, FIELD, METHOD })
047public @interface NotNull {
048
049    /**
050     * {@link AntTaskAttributeConstraint.Checker}.
051     */
052    @NoArgsConstructor @ToString
053    public static class Checker extends AntTaskAttributeConstraint.Checker {
054        @Override
055        protected void check(Task task, TaskConfigurationChecker checker,
056                             String name, Object value) {
057            checker.assertConfig(value != null,
058                                 "`" + name + "' attribute must not be null");
059        }
060    }
061}