Added simple fix for infinite recursion in entity mapping if class contains a field of same type as the class. In such case will skip that field.

Author: Jakub Vavrik

src/main/java/org/springframework/data/elasticsearch/core/MappingBuilder.java

@@ -25,7 +25,9 @@
 import org.springframework.data.util.TypeInformation;
 
 import java.io.IOException;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 
 import static org.apache.commons.lang.StringUtils.EMPTY;
 import static org.apache.commons.lang.StringUtils.isNotBlank;
@@ -57,14 +59,13 @@ class MappingBuilder {
     static XContentBuilder buildMapping(Class clazz, String indexType, String idFieldName) throws IOException {
         XContentBuilder xContentBuilder = jsonBuilder().startObject().startObject(indexType).startObject(FIELD_PROPERTIES);
 
-        mapEntity(xContentBuilder, clazz, true, idFieldName, EMPTY);
+        mapEntity(xContentBuilder, clazz, true, idFieldName, EMPTY, new HashSet<Class>());
 
         return xContentBuilder.endObject().endObject().endObject();
     }
 
     private static void mapEntity(XContentBuilder xContentBuilder, Class clazz, boolean isRootObject, String idFieldName,
-                                  String nestedObjectFieldName) throws IOException {
-
+                    String nestedObjectFieldName, Set<Class> ancestorClasses) throws IOException {
         java.lang.reflect.Field[] fields = clazz.getDeclaredFields();
 
         if (!isRootObject && isAnyPropertyAnnotatedAsField(fields)) {
@@ -78,7 +79,12 @@ private static void mapEntity(XContentBuilder xContentBuilder, Class clazz, bool
             }
 
             if (isEntity(field)) {
-                mapEntity(xContentBuilder, field.getType(), false, EMPTY, field.getName());
+                if (ancestorClasses.contains(field.getType())) {
+                    continue;
+                } else {
+                    ancestorClasses.add(field.getType());
+                    mapEntity(xContentBuilder, field.getType(), false, EMPTY, field.getName(), ancestorClasses);
+                }
             }
 
             Field singleField = field.getAnnotation(Field.class);