ReflectionTestUtils does not require spring-aop on the classpath

Issue: SPR-15757

build.gradle

@@ -1008,11 +1008,12 @@ project("spring-test") {
 
 	dependencies {
 		compile(project(":spring-core"))
+		optional(project(":spring-aop"))
 		optional(project(":spring-beans"))
 		optional(project(":spring-context"))
 		optional(project(":spring-jdbc"))
-		optional(project(":spring-tx"))
 		optional(project(":spring-orm"))
+		optional(project(":spring-tx"))
 		optional(project(":spring-web"))
 		optional(project(":spring-webflux"))
 		optional(project(":spring-webmvc"))

spring-test/src/main/java/org/springframework/test/util/ReflectionTestUtils.java

@@ -24,6 +24,7 @@ import org.apache.commons.logging.LogFactory;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.MethodInvoker;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.ReflectionUtils;
@@ -71,6 +72,9 @@ public class ReflectionTestUtils {
 
 	private static final Log logger = LogFactory.getLog(ReflectionTestUtils.class);
 
+	private static final boolean springAopPresent = ClassUtils.isPresent(
+			"org.springframework.aop.framework.Advised", ReflectionTestUtils.class.getClassLoader());
+
 
 	/**
 	 * Set the {@linkplain Field field} with the given {@code name} on the
@@ -169,26 +173,27 @@ public class ReflectionTestUtils {
 		Assert.isTrue(targetObject != null || targetClass != null,
 				"Either targetObject or targetClass for the field must be specified");
 
-		Object ultimateTarget = (targetObject != null ? AopTestUtils.getUltimateTargetObject(targetObject) : null);
-
+		if (targetObject != null && springAopPresent) {
+			targetObject = AopTestUtils.getUltimateTargetObject(targetObject);
+		}
 		if (targetClass == null) {
-			targetClass = ultimateTarget.getClass();
+			targetClass = targetObject.getClass();
 		}
 
 		Field field = ReflectionUtils.findField(targetClass, name, type);
 		if (field == null) {
 			throw new IllegalArgumentException(String.format(
 					"Could not find field '%s' of type [%s] on %s or target class [%s]", name, type,
-					safeToString(ultimateTarget), targetClass));
+					safeToString(targetObject), targetClass));
 		}
 
 		if (logger.isDebugEnabled()) {
 			logger.debug(String.format(
 					"Setting field '%s' of type [%s] on %s or target class [%s] to value [%s]", name, type,
-					safeToString(ultimateTarget), targetClass, value));
+					safeToString(targetObject), targetClass, value));
 		}
 		ReflectionUtils.makeAccessible(field);
-		ReflectionUtils.setField(field, ultimateTarget, value);
+		ReflectionUtils.setField(field, targetObject, value);
 	}
 
 	/**
@@ -253,24 +258,25 @@ public class ReflectionTestUtils {
 		Assert.isTrue(targetObject != null || targetClass != null,
 			"Either targetObject or targetClass for the field must be specified");
 
-		Object ultimateTarget = (targetObject != null ? AopTestUtils.getUltimateTargetObject(targetObject) : null);
-
+		if (targetObject != null && springAopPresent) {
+			targetObject = AopTestUtils.getUltimateTargetObject(targetObject);
+		}
 		if (targetClass == null) {
-			targetClass = ultimateTarget.getClass();
+			targetClass = targetObject.getClass();
 		}
 
 		Field field = ReflectionUtils.findField(targetClass, name);
 		if (field == null) {
 			throw new IllegalArgumentException(String.format("Could not find field '%s' on %s or target class [%s]",
-					name, safeToString(ultimateTarget), targetClass));
+					name, safeToString(targetObject), targetClass));
 		}
 
 		if (logger.isDebugEnabled()) {
 			logger.debug(String.format("Getting field '%s' from %s or target class [%s]", name,
-					safeToString(ultimateTarget), targetClass));
+					safeToString(targetObject), targetClass));
 		}
 		ReflectionUtils.makeAccessible(field);
-		return ReflectionUtils.getField(field, ultimateTarget);
+		return ReflectionUtils.getField(field, targetObject);
 	}
 
 	/**