Use streams and lambdas in spring-test where feasible

Issue: SPR-13188

spring-test/src/main/java/org/springframework/test/context/jdbc/SqlScriptsTestExecutionListener.java

@@ -40,10 +40,8 @@ import org.springframework.test.context.transaction.TestContextTransactionUtils;
 import org.springframework.test.context.util.TestContextResourceUtils;
 import org.springframework.transaction.PlatformTransactionManager;
 import org.springframework.transaction.TransactionDefinition;
-import org.springframework.transaction.TransactionStatus;
 import org.springframework.transaction.interceptor.DefaultTransactionAttribute;
 import org.springframework.transaction.interceptor.TransactionAttribute;
-import org.springframework.transaction.support.TransactionCallbackWithoutResult;
 import org.springframework.transaction.support.TransactionTemplate;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
@@ -244,12 +242,9 @@ public class SqlScriptsTestExecutionListener extends AbstractTestExecutionListen
 			TransactionAttribute transactionAttribute = TestContextTransactionUtils.createDelegatingTransactionAttribute(
 				testContext, new DefaultTransactionAttribute(propagation));
 
-			new TransactionTemplate(transactionManager, transactionAttribute).execute(new TransactionCallbackWithoutResult() {
-
-				@Override
-				public void doInTransactionWithoutResult(TransactionStatus status) {
-					populator.execute(finalDataSource);
-				}
+			new TransactionTemplate(transactionManager, transactionAttribute).execute(status -> {
+				populator.execute(finalDataSource);
+				return null;
 			});
 		}
 	}

spring-test/src/main/java/org/springframework/test/context/transaction/TransactionalTestExecutionListener.java

@@ -19,9 +19,10 @@ package org.springframework.test.context.transaction;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -442,13 +443,9 @@ public class TransactionalTestExecutionListener extends AbstractTestExecutionLis
 	 * as well as annotated interface default methods
 	 */
 	private List<Method> getAnnotatedMethods(Class<?> clazz, Class<? extends Annotation> annotationType) {
-		List<Method> methods = new ArrayList<>(4);
-		for (Method method : ReflectionUtils.getUniqueDeclaredMethods(clazz)) {
-			if (AnnotationUtils.getAnnotation(method, annotationType) != null) {
-				methods.add(method);
-			}
-		}
-		return methods;
+		return Arrays.stream(ReflectionUtils.getUniqueDeclaredMethods(clazz))
+				.filter(method -> AnnotatedElementUtils.hasAnnotation(method, annotationType))
+				.collect(Collectors.toList());
 	}
 
 	/**

spring-test/src/main/java/org/springframework/test/context/util/TestContextResourceUtils.java

@@ -16,8 +16,10 @@
 
 package org.springframework.test.context.util;
 
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
@@ -98,8 +100,7 @@ public abstract class TestContextResourceUtils {
 	 * @see #convertToClasspathResourcePaths
 	 */
 	public static Resource[] convertToResources(ResourceLoader resourceLoader, String... paths) {
-		List<Resource> list = convertToResourceList(resourceLoader, paths);
-		return list.toArray(new Resource[list.size()]);
+		return stream(resourceLoader, paths).toArray(Resource[]::new);
 	}
 
 	/**
@@ -114,11 +115,11 @@ public abstract class TestContextResourceUtils {
 	 * @see #convertToClasspathResourcePaths
 	 */
 	public static List<Resource> convertToResourceList(ResourceLoader resourceLoader, String... paths) {
-		List<Resource> list = new ArrayList<>();
-		for (String path : paths) {
-			list.add(resourceLoader.getResource(path));
-		}
-		return list;
+		return stream(resourceLoader, paths).collect(Collectors.toList());
+	}
+
+	private static Stream<Resource> stream(ResourceLoader resourceLoader, String... paths) {
+		return Arrays.stream(paths).map(resourceLoader::getResource);
 	}
 
 }