BATCH-2185: Updated to support annotation based listener configuration via javaconfig

spring-batch-infrastructure/src/main/java/org/springframework/batch/support/ReflectionUtils.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.support;
+
+import org.springframework.core.annotation.AnnotationUtils;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Provides reflection based utilities for Spring Batch that are not available
+ * via Spring Core
+ *
+ * @author Michael Minella
+ * @since 2.2.6
+ */
+public class ReflectionUtils {
+
+	private ReflectionUtils() {}
+
+	/**
+	 * Returns a {@link java.util.Set} of {@link java.lang.reflect.Method} instances that
+	 * are annotated with the annotation provided.
+	 *
+	 * @param clazz The class to search for a method with the given annotation type
+	 * @param annotationType The type of annotation to look for
+	 * @return a set of {@link java.lang.reflect.Method} instances if any are found, an empty set if not.
+	 */
+	public static final Set<Method> findMethod(Class clazz, Class<? extends Annotation> annotationType) {
+
+		Method [] declaredMethods = org.springframework.util.ReflectionUtils.getAllDeclaredMethods(clazz);
+		Set<Method> results = new HashSet<Method>();
+
+		for (Method curMethod : declaredMethods) {
+			Annotation annotation = AnnotationUtils.findAnnotation(curMethod, annotationType);
+
+			if(annotation != null) {
+				results.add(curMethod);
+			}
+		}
+
+		return results;
+	}
+}

spring-batch-infrastructure/src/test/java/org/springframework/batch/support/ReflectionUtilsTests.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.support;
+
+import org.junit.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.lang.reflect.Method;
+import java.util.Iterator;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author Michael Minella
+ * @since 2.2.6
+ */
+public class ReflectionUtilsTests {
+
+	@Test
+	public void testFindAnnotatedMethod() {
+		Set<Method> methods = ReflectionUtils.findMethod(AnnotatedClass.class, Transactional.class);
+		assertEquals(1, methods.size());
+		assertEquals("toString", methods.iterator().next().getName());
+	}
+
+	@Test
+	public void testFindNoAnnotatedMethod() {
+		Set<Method> methods = ReflectionUtils.findMethod(AnnotatedClass.class, Autowired.class);
+		assertEquals(0, methods.size());
+	}
+
+	@Test
+	public void testFindAnnotatedMethodHierarchy() {
+		Set<Method> methods = ReflectionUtils.findMethod(AnnotatedSubClass.class, Transactional.class);
+		assertEquals(2, methods.size());
+
+		boolean toStringFound = false;
+		boolean methodOneFound = false;
+
+		Iterator<Method> iterator = methods.iterator();
+
+		String name = iterator.next().getName();
+
+		if(name.equals("toString")) {
+			toStringFound = true;
+		} else if(name.equals("methodOne")) {
+			methodOneFound = true;
+		}
+
+		name = iterator.next().getName();
+
+		if(name.equals("toString")) {
+			toStringFound = true;
+		} else if(name.equals("methodOne")) {
+			methodOneFound = true;
+		}
+
+		assertTrue(toStringFound && methodOneFound);
+	}
+
+	public static class AnnotatedClass {
+
+		public void methodOne() {
+			System.err.println("This is method 1");
+		}
+
+		@Transactional
+		public String toString() {
+			return "AnnoatedClass";
+		}
+	}
+
+	public static class AnnotatedSubClass extends AnnotatedClass {
+
+		@Transactional
+		public void methodOne() {
+			System.err.println("This is method 1 in the sub class");
+		}
+	}
+}