Polishing.

Original pull request #2324

src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java

@@ -333,8 +333,8 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 				continue;
 			}
 
-			// may cause NullPointerException if the returned value is null
-			return (boolean) AnnotationUtils.getValue(annotation, "updatable");
+			final Object updatable = AnnotationUtils.getValue(annotation, "updatable");
+			return (boolean) (updatable == null ? true : updatable);
 		}
 
 		return true;

src/main/java/org/springframework/data/jpa/repository/config/JpaRepositoryConfigExtension.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jpa.repository.config;
 
+import static org.springframework.data.jpa.repository.config.BeanDefinitionNames.*;
+
 import java.lang.annotation.Annotation;
 import java.util.Arrays;
 import java.util.Collection;
@@ -52,8 +54,6 @@ import org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcesso
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
-import static org.springframework.data.jpa.repository.config.BeanDefinitionNames.*;
-
 /**
  * JPA specific configuration extension parsing custom attributes from the XML namespace and
  * {@link EnableJpaRepositories} annotation. Also, it registers bean definitions for a

src/main/java/org/springframework/data/jpa/repository/query/StringQuery.java

@@ -263,6 +263,7 @@ class StringQuery implements DeclaredQuery {
 				Integer parameterIndex = getParameterIndex(parameterIndexString);
 
 				String typeSource = matcher.group(COMPARISION_TYPE_GROUP);
+				Assert.isTrue(parameterIndexString != null || parameterName != null, () -> String.format("We need either a name or an index! Offending query string: %s", query));
 				String expression = spelExtractor.getParameter(parameterName == null ? parameterIndexString : parameterName);
 				String replacement = null;