DATACMNS-695 - Fixed potential NullPointerException in AbstractMappingContext.getPersistentPropertyPath(…).

When traversing nested property paths, AbstractMappingContext.getPersistentPropertyPath(…) previously used the raw actual property type. If the property path contains a reference to a generically typed property, this causes the deeper paths not being resolved correctly.

We now explicitly use the TypeInformation of the property to retain generics information while traversing the path.

Author: odrotbohm

src/main/java/org/springframework/data/mapping/context/AbstractMappingContext.java

@@ -239,7 +239,7 @@ private PersistentPropertyPath<P> getPersistentPropertyPath(Iterable<String> par
 			result.add(persistentProperty);
 
 			if (iterator.hasNext()) {
-				current = getPersistentEntity(persistentProperty.getActualType());
+				current = getPersistentEntity(persistentProperty.getTypeInformation().getActualType());
 			}
 		}
 

src/test/java/org/springframework/data/mapping/context/AbstractMappingContextUnitTests.java

@@ -25,6 +25,7 @@
 import java.util.List;
 import java.util.TreeMap;
 
+import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -245,6 +246,15 @@ public void doesNotAddMapImplementationClassesAsPersistentEntity() {
 		assertHasEntityFor(TreeMap.class, context, false);
 	}
 
+	/**
+	 * @see DATACMNS-695
+	 */
+	@Test
+	public void persistentPropertyPathTraversesGenericTypesCorrectly() {
+		assertThat(context.getPersistentPropertyPath("field.wrapped.field", Outer.class),
+				is(Matchers.<SamplePersistentProperty> iterableWithSize(3)));
+	}
+
 	private static void assertHasEntityFor(Class<?> type, SampleMappingContext context, boolean expected) {
 
 		boolean found = false;
@@ -283,4 +293,17 @@ static class Base {
 	static class Extension extends Base {
 		@Id String foo;
 	}
+
+	static class Outer {
+
+		Wrapper<Inner> field;
+	}
+
+	static class Wrapper<T> {
+		T wrapped;
+	}
+
+	static class Inner {
+		String field;
+	}
 }