SOLR-12362: Uploading docs in JSON now supports child documents as field values

solr/CHANGES.txt

@@ -74,6 +74,10 @@ New Features
 
 * SOLR-12474: Add an UpdateRequest Object that implements RequestWriter.ContentWriter (noble)
 
+* SOLR-12362: Uploading docs in JSON now supports child documents as field values, thus providing a label to the
+  relationship instead of the current "anonymous" relationship.  Use of this experimental feature requires
+  anonChildDocs=false parameter.  (Moshe Bla, David Smiley)
+
 Bug Fixes
 ----------------------
 

solr/core/src/java/org/apache/solr/handler/loader/JsonLoader.java

@@ -93,11 +93,16 @@ public class JsonLoader extends ContentStreamLoader {
     protected JSONParser parser;
     protected final int commitWithin;
     protected final boolean overwrite;
+    protected final boolean anonChildDoc;
 
+    /**
+     * {@link CommonParams#ANONYMOUS_CHILD_DOCS} Defaults to true.
+     */
     public SingleThreadedJsonLoader(SolrQueryRequest req, SolrQueryResponse rsp, UpdateRequestProcessor processor) {
       this.processor = processor;
       this.req = req;
       this.rsp = rsp;
+      this.anonChildDoc = req.getParams().getBool(CommonParams.ANONYMOUS_CHILD_DOCS, true);
 
       commitWithin = req.getParams().getInt(UpdateParams.COMMIT_WITHIN, -1);
       overwrite = req.getParams().getBool(UpdateParams.OVERWRITE, true);
@@ -248,14 +253,28 @@ public class JsonLoader extends ContentStreamLoader {
     private SolrInputDocument buildDoc(Map<String, Object> m) {
       SolrInputDocument result = new SolrInputDocument();
       for (Map.Entry<String, Object> e : m.entrySet()) {
-        if (e.getKey() == null) {// special case. JsonRecordReader emits child docs with null key
+        if (mapEntryIsChildDoc(e.getValue())) { // parse child documents
           if (e.getValue() instanceof List) {
             List value = (List) e.getValue();
             for (Object o : value) {
-              if (o instanceof Map) result.addChildDocument(buildDoc((Map) o));
+              if (o instanceof Map) {
+                if (anonChildDoc) {
+                  result.addChildDocument(buildDoc((Map) o));
+                } else {
+                  // retain the value as a list, even if the list contains a single value.
+                  if(!result.containsKey(e.getKey())) {
+                    result.setField(e.getKey(), new ArrayList<>(1));
+                  }
+                  result.addField(e.getKey(), buildDoc((Map) o));
+                }
+              }
             }
           } else if (e.getValue() instanceof Map) {
+            if (anonChildDoc) {
               result.addChildDocument(buildDoc((Map) e.getValue()));
+            } else {
+              result.addField(e.getKey(), buildDoc((Map) e.getValue()));
+            }
           }
         } else {
           result.setField(e.getKey(), e.getValue());
@@ -530,7 +549,7 @@ public class JsonLoader extends ContentStreamLoader {
         }
         String fieldName = parser.getString();
 
-        if (fieldName.equals(JsonLoader.CHILD_DOC_KEY)) {
+        if (anonChildDoc && fieldName.equals(JsonLoader.CHILD_DOC_KEY)) {
           ev = parser.nextEvent();
           assertEvent(ev, JSONParser.ARRAY_START);
           while ((ev = parser.nextEvent()) != JSONParser.ARRAY_END) {
@@ -554,41 +573,53 @@ public class JsonLoader extends ContentStreamLoader {
     private void parseFieldValue(SolrInputField sif) throws IOException {
       int ev = parser.nextEvent();
       if (ev == JSONParser.OBJECT_START) {
-        parseExtendedFieldValue(sif, ev);
+        parseExtendedFieldValue(ev, sif);
       } else {
-        Object val = parseNormalFieldValue(ev, sif.getName());
+        Object val = parseNormalFieldValue(ev, sif);
         sif.setValue(val);
       }
     }
 
-    private void parseExtendedFieldValue(SolrInputField sif, int ev) throws IOException {
+    /**
+     * A method to either extract an index time boost (deprecated), a map for atomic update, or a child document.
+     * firstly, a solr document SolrInputDocument constructed. It is then determined whether the document is indeed a childDocument(if it has a unique field).
+     * If so, it is added.
+     * Otherwise the document is looped over as a map, and is then parsed as an Atomic Update if that is the case.
+     * @param ev json parser event
+     * @param sif input field to add value to.
+     * @throws IOException in case of parsing exception.
+     */
+    private void parseExtendedFieldValue(int ev, SolrInputField sif) throws IOException {
       assert ev == JSONParser.OBJECT_START;
 
+      SolrInputDocument extendedSolrDocument = parseDoc(ev);
+
+      if (isChildDoc(extendedSolrDocument)) {
+        sif.addValue(extendedSolrDocument);
+        return;
+      }
+
       Object normalFieldValue = null;
       Map<String, Object> extendedInfo = null;
 
-      for (; ; ) {
+      for (SolrInputField entry: extendedSolrDocument) {
-        ev = parser.nextEvent();
+        Object val = entry.getValue();
-        switch (ev) {
+        String label = entry.getName();
-          case JSONParser.STRING:
-            String label = parser.getString();
         if ("boost".equals(label)) {
-              ev = parser.nextEvent();
+          Object boostVal = val;
-              if (ev != JSONParser.NUMBER &&
+          if (!(boostVal instanceof Double)) {
-                  ev != JSONParser.LONG &&
-                  ev != JSONParser.BIGNUMBER) {
             throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Boost should have number. "
-                    + "Unexpected " + JSONParser.getEventString(ev) + " at [" + parser.getPosition() + "], field=" + sif.getName());
+                + "Unexpected value: " + boostVal.toString() + "field=" + label);
           }
 
-              String message = "Ignoring field boost: " + parser.getDouble() + " as index-time boosts are not supported anymore";
+          String message = "Ignoring field boost: " + boostVal.toString() + " as index-time boosts are not supported anymore";
           if (WARNED_ABOUT_INDEX_TIME_BOOSTS.compareAndSet(false, true)) {
             log.warn(message);
           } else {
             log.debug(message);
           }
         } else if ("value".equals(label)) {
-              normalFieldValue = parseNormalFieldValue(parser.nextEvent(), sif.getName());
+          normalFieldValue = val;
         } else {
           // If we encounter other unknown map keys, then use a map
           if (extendedInfo == null) {
@@ -596,12 +627,8 @@ public class JsonLoader extends ContentStreamLoader {
           }
           // for now, the only extended info will be field values
           // we could either store this as an Object or a SolrInputField
-              Object val = parseNormalFieldValue(parser.nextEvent(), sif.getName());
           extendedInfo.put(label, val);
         }
-            break;
-
-          case JSONParser.OBJECT_END:
         if (extendedInfo != null) {
           if (normalFieldValue != null) {
             extendedInfo.put("value", normalFieldValue);
@@ -610,28 +637,15 @@ public class JsonLoader extends ContentStreamLoader {
         } else {
           sif.setValue(normalFieldValue);
         }
-            return;
-
-          default:
-            throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Error parsing JSON extended field value. "
-                + "Unexpected " + JSONParser.getEventString(ev) + " at [" + parser.getPosition() + "], field=" + sif.getName());
-        }
-      }
-    }
-
-
-    private Object parseNormalFieldValue(int ev, String fieldName) throws IOException {
-      if (ev == JSONParser.ARRAY_START) {
-        List<Object> val = parseArrayFieldValue(ev, fieldName);
-        return val;
-      } else {
-        Object val = parseSingleFieldValue(ev, fieldName);
-        return val;
       }
     }
 
 
-    private Object parseSingleFieldValue(int ev, String fieldName) throws IOException {
+    private Object parseNormalFieldValue(int ev, SolrInputField sif) throws IOException {
+      return ev == JSONParser.ARRAY_START ? parseArrayFieldValue(ev, sif): parseSingleFieldValue(ev, sif);
+    }
+
+    private Object parseSingleFieldValue(int ev, SolrInputField sif) throws IOException {
       switch (ev) {
         case JSONParser.STRING:
           return parser.getString();
@@ -647,15 +661,18 @@ public class JsonLoader extends ContentStreamLoader {
           parser.getNull();
           return null;
         case JSONParser.ARRAY_START:
-          return parseArrayFieldValue(ev, fieldName);
+          return parseArrayFieldValue(ev, sif);
+        case JSONParser.OBJECT_START:
+          parseExtendedFieldValue(ev, sif);
+          return sif.getValue();
         default:
           throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Error parsing JSON field value. "
-              + "Unexpected " + JSONParser.getEventString(ev) + " at [" + parser.getPosition() + "], field=" + fieldName);
+              + "Unexpected " + JSONParser.getEventString(ev) + " at [" + parser.getPosition() + "], field=" + sif.getName());
       }
     }
 
 
-    private List<Object> parseArrayFieldValue(int ev, String fieldName) throws IOException {
+    private List<Object> parseArrayFieldValue(int ev, SolrInputField sif) throws IOException {
       assert ev == JSONParser.ARRAY_START;
 
       ArrayList lst = new ArrayList(2);
@@ -664,10 +681,24 @@ public class JsonLoader extends ContentStreamLoader {
         if (ev == JSONParser.ARRAY_END) {
           return lst;
         }
-        Object val = parseSingleFieldValue(ev, fieldName);
+        Object val = parseSingleFieldValue(ev, sif);
         lst.add(val);
+        sif.setValue(null);
       }
     }
+
+    private boolean isChildDoc(SolrInputDocument extendedFieldValue) {
+      return extendedFieldValue.containsKey(req.getSchema().getUniqueKeyField().getName());
+    }
+
+    private boolean mapEntryIsChildDoc(Object val) {
+      if(val instanceof List) {
+        List listVal = (List) val;
+        if (listVal.size() == 0) return false;
+        return  listVal.get(0) instanceof Map;
+      }
+      return val instanceof Map;
+    }
   }
 
   private static Object changeChildDoc(Object o) {

solr/core/src/test/org/apache/solr/handler/JsonLoaderTest.java

@@ -16,6 +16,11 @@
  */
 package org.apache.solr.handler;
 
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.function.UnaryOperator;
+
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrException;
 import org.apache.solr.common.SolrInputDocument;
@@ -32,10 +37,7 @@ import org.junit.BeforeClass;
 import org.junit.Test;
 import org.noggit.ObjectBuilder;
 
-import java.util.Collections;
+import static org.apache.solr.common.params.CommonParams.ANONYMOUS_CHILD_DOCS;
-import java.util.List;
-import java.util.Map;
-import java.util.function.UnaryOperator;
 
 public class JsonLoaderTest extends SolrTestCaseJ4 {
 
@@ -411,6 +413,7 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       "      \"id\": \"1.2\",\n" +
       "      \"name\": \"i am the 2nd child\",\n" +
       "      \"cat\": \"child\",\n" +
+      "      \"test_s\": \"test-new-label\",\n" +
       "      \"grandchildren\": [\n" +
       "        {\n" +
       "          \"id\": \"1.2.1\",\n" +
@@ -432,13 +435,23 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       "f", "name:/children/grandchildren/name",
       "f", "cat:/children/grandchildren/cat"};
 
+  @Test
+  public void testFewParentsAnonymousJsonDoc() throws Exception {
+    String json = PARENT_TWO_CHILDREN_JSON;
+    assertFewParents(json, true);
+  }
+
+  @Test
   public void testFewParentsJsonDoc() throws Exception {
     String json = PARENT_TWO_CHILDREN_JSON;
+    assertFewParents(json, false);
+  }
+
+  private void assertFewParents(String json, boolean anonChildDocsFlag) throws Exception {
     SolrQueryRequest req;
     SolrQueryResponse rsp;
     BufferingRequestProcessor p;
-    JsonLoader loader;
+    JsonLoader loader;//multichild test case
-    { //multichild test case
     final boolean array = random().nextBoolean();
     StringBuilder b = new StringBuilder();
     if (array) {
@@ -452,7 +465,7 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       }
     }
 
-      req = req(PARENT_TWO_CHILDREN_PARAMS);
+    req = req(PARENT_TWO_CHILDREN_PARAMS, ANONYMOUS_CHILD_DOCS, Boolean.toString(anonChildDocsFlag));
     req.getContext().put("path", "/update/json/docs");
     rsp = new SolrQueryResponse();
     p = new BufferingRequestProcessor(null);
@@ -466,28 +479,42 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       assertOnlyValue("i am the parent", parent, "name");
       assertOnlyValue("parent", parent, "cat");
 
-        assertEquals(2, parent.getChildDocuments().size());
+      List<SolrInputDocument> childDocs1;
+      if(anonChildDocsFlag) {
+        childDocs1 = parent.getChildDocuments();
+      } else {
+        childDocs1 = (List) ((parent.getField("children")).getValue());
+      }
+
+      assertEquals(2, childDocs1.size());
       {
-          final SolrInputDocument child1 = parent.getChildDocuments().get(0);
+        final SolrInputDocument child1 = childDocs1.get(0);
         assertOnlyValue(s.apply("1.1"), child1, "id");
         assertOnlyValue(s.apply("i am the 1st child"), child1, "name");
         assertOnlyValue("child", child1,"cat");
       }
       {
-          final SolrInputDocument child2 = parent.getChildDocuments().get(1);
+        final SolrInputDocument child2 = childDocs1.get(1);
         assertOnlyValue(s.apply("1.2"), child2, "id");
         assertOnlyValue("i am the 2nd child", child2, "name");
+        assertOnlyValue("test-new-label", child2, "test_s");
         assertOnlyValue("child", child2, "cat");
 
-          assertEquals(1, child2.getChildDocuments().size());
+        List<SolrInputDocument> childDocs2;
-          final SolrInputDocument grandChild = child2.getChildDocuments().get(0);
+        if(anonChildDocsFlag) {
+          childDocs2 = child2.getChildDocuments();
+        } else {
+          childDocs2 = (List) ((child2.getField("grandchildren")).getValue());
+        }
+
+        assertEquals(1, childDocs2.size());
+        final SolrInputDocument grandChild = childDocs2.get(0);
         assertOnlyValue(s.apply("1.2.1"), grandChild,"id");
         assertOnlyValue("i am the grandchild", grandChild, "name");
         assertOnlyValue("grandchild", grandChild, "cat");
       }
     }
   }
-  }
 
   private static void assertOnlyValue(String expected, SolrInputDocument doc, String field) {
     assertEquals(Collections.singletonList(expected), doc.getFieldValues(field));
@@ -790,9 +817,7 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
     req.close();
   }
 
-  @Test
+  private static final String SIMPLE_JSON_CHILD_DOCS = "{\n" +
-  public void testSimpleChildDocs() throws Exception {
-    String str = "{\n" +
       "    \"add\": {\n" +
       "        \"doc\": {\n" +
       "            \"id\": \"1\",\n" +
@@ -808,12 +833,18 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       "        }\n" +
       "    }\n" +
       "}";
-    checkTwoChildDocs(str);
+
+  @Test
+  public void testSimpleAnonymousChildDocs() throws Exception {
+    checkTwoAnonymousChildDocs(SIMPLE_JSON_CHILD_DOCS);
   }
 
   @Test
-  public void testDupKeysChildDocs() throws Exception {
+  public void testSimpleChildDocs() throws Exception {
-    String str = "{\n" +
+    checkTwoAnonymousChildDocs(SIMPLE_JSON_CHILD_DOCS, false);
+  }
+
+  private static final String DUP_KEYS_JSON_CHILD_DOCS = "{\n" +
       "    \"add\": {\n" +
       "        \"doc\": {\n" +
       "            \"_childDocuments_\": [\n" +
@@ -832,11 +863,23 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
       "        }\n" +
       "    }\n" +
       "}";
-    checkTwoChildDocs(str);
+
+  @Test
+  public void testDupKeysAnonymousChildDocs() throws Exception {
+    checkTwoAnonymousChildDocs(DUP_KEYS_JSON_CHILD_DOCS);
   }
 
-  private void checkTwoChildDocs(String rawJsonStr) throws Exception {
+  @Test
-    SolrQueryRequest req = req("commit","true");
+  public void testDupKeysChildDocs() throws Exception {
+    checkTwoAnonymousChildDocs(DUP_KEYS_JSON_CHILD_DOCS, false);
+  }
+
+  private void checkTwoAnonymousChildDocs(String rawJsonStr) throws Exception {
+    checkTwoAnonymousChildDocs(rawJsonStr, true);
+  }
+
+  private void checkTwoAnonymousChildDocs(String rawJsonStr, boolean anonChildDocs) throws Exception {
+    SolrQueryRequest req = req("commit","true", ANONYMOUS_CHILD_DOCS, Boolean.toString(anonChildDocs));
     SolrQueryResponse rsp = new SolrQueryResponse();
     BufferingRequestProcessor p = new BufferingRequestProcessor(null);
     JsonLoader loader = new JsonLoader();
@@ -849,11 +892,20 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
     SolrInputField f = d.getField( "id" );
     assertEquals("1", f.getValue());
 
-    SolrInputDocument cd = d.getChildDocuments().get(0);
+    SolrInputDocument cd;
+    if (anonChildDocs) {
+      cd = d.getChildDocuments().get(0);
+    } else {
+      cd = (SolrInputDocument) (d.getField("_childDocuments_")).getFirstValue();
+    }
     SolrInputField cf = cd.getField( "id" );
     assertEquals("2", cf.getValue());
 
+    if (anonChildDocs) {
       cd = d.getChildDocuments().get(1);
+    } else {
+      cd = (SolrInputDocument)((List)(d.getField("_childDocuments_")).getValue()).get(1);
+    }
     cf = cd.getField( "id" );
     assertEquals("3", cf.getValue());
     cf = cd.getField( "foo_i" );
@@ -865,7 +917,7 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
   }
 
   @Test
-  public void testEmptyChildDocs() throws Exception {
+  public void testEmptyAnonymousChildDocs() throws Exception {
     String str = "{\n" +
         "    \"add\": {\n" +
         "        \"doc\": {\n" +
@@ -893,7 +945,7 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
   }
 
   @Test
-  public void testGrandChildDocs() throws Exception {
+  public void testAnonymousGrandChildDocs() throws Exception {
     String str = "{\n" +
         "    \"add\": {\n" +
         "        \"doc\": {\n" +
@@ -946,5 +998,87 @@ public class JsonLoaderTest extends SolrTestCaseJ4 {
 
   }
 
+  @Test
+  public void testChildDocs() throws Exception {
+    String str = "{\n" +
+        "    \"add\": {\n" +
+        "        \"doc\": {\n" +
+        "            \"id\": \"1\",\n" +
+        "            \"children\": [\n" +
+        "                {\n" +
+        "                    \"id\": \"2\",\n" +
+        "                    \"foo_s\": \"Yaz\"\n" +
+        "                },\n" +
+        "                {\n" +
+        "                    \"id\": \"3\",\n" +
+        "                    \"foo_s\": \"Bar\"\n" +
+        "                }\n" +
+        "            ]\n" +
+        "        }\n" +
+        "    }\n" +
+        "}";
+
+    SolrQueryRequest req = req("commit","true");
+    SolrQueryResponse rsp = new SolrQueryResponse();
+    BufferingRequestProcessor p = new BufferingRequestProcessor(null);
+    JsonLoader loader = new JsonLoader();
+    loader.load(req, rsp, new ContentStreamBase.StringStream(str), p);
+
+    assertEquals( 1, p.addCommands.size() );
+
+    AddUpdateCommand add = p.addCommands.get(0);
+    SolrInputDocument one = add.solrDoc;
+    assertEquals("1", one.getFieldValue("id"));
+
+    List<SolrInputDocument> children = (List) one.getFieldValues("children");
+    SolrInputDocument two = children.get(0);
+    assertEquals("2", two.getFieldValue("id"));
+    assertEquals("Yaz", two.getFieldValue("foo_s"));
+
+    SolrInputDocument three = children.get(1);
+    assertEquals("3", three.getFieldValue("id"));
+    assertEquals("Bar", three.getFieldValue("foo_s"));
+
+    req.close();
+
+  }
+
+  @Test
+  public void testSingleRelationalChildDoc() throws Exception {
+    String str = "{\n" +
+        "    \"add\": {\n" +
+        "        \"doc\": {\n" +
+        "            \"id\": \"1\",\n" +
+        "            \"child1\": \n" +
+        "                {\n" +
+        "                    \"id\": \"2\",\n" +
+        "                    \"foo_s\": \"Yaz\"\n" +
+        "                },\n" +
+        "        }\n" +
+        "    }\n" +
+        "}";
+
+    SolrQueryRequest req = req("commit","true");
+    SolrQueryResponse rsp = new SolrQueryResponse();
+    BufferingRequestProcessor p = new BufferingRequestProcessor(null);
+    JsonLoader loader = new JsonLoader();
+    loader.load(req, rsp, new ContentStreamBase.StringStream(str), p);
+
+    assertEquals( 1, p.addCommands.size() );
+
+    AddUpdateCommand add = p.addCommands.get(0);
+    SolrInputDocument one = add.solrDoc;
+    assertEquals("1", one.getFieldValue("id"));
+
+    assertTrue(one.keySet().contains("child1"));
+
+    SolrInputDocument two = (SolrInputDocument) one.getField("child1").getValue();
+    assertEquals("2", two.getFieldValue("id"));
+    assertEquals("Yaz", two.getFieldValue("foo_s"));
+
+    req.close();
+
+  }
+
 
 }

solr/solrj/src/java/org/apache/solr/common/SolrInputField.java

@@ -87,8 +87,8 @@ public class SolrInputField implements Iterable<Object>, Serializable
       value = vals;
     }
     
-    // Add the new values to a collection
+    // Add the new values to a collection, if childDoc add as is without iteration
-    if( v instanceof Iterable ) {
+    if( v instanceof Iterable && !(v instanceof SolrDocumentBase)) {
       for( Object o : (Iterable<Object>)v ) {
         vals.add( o );
       }

solr/solrj/src/java/org/apache/solr/common/params/CommonParams.java

@@ -290,5 +290,11 @@ public interface CommonParams {
   String JSON_MIME = "application/json";
 
   String JAVABIN_MIME = "application/javabin";
+
+  /**
+   * If set to true, child documents will be added as anonymous children into the _childDocuments list,
+   * else, child documents will be added to SolrInputDocument as field values according to their key name.
+   */
+  String ANONYMOUS_CHILD_DOCS = "anonChildDocs";
 }
 

solr/solrj/src/java/org/apache/solr/common/util/JsonRecordReader.java

@@ -288,13 +288,13 @@ public class JsonRecordReader {
         event = parser.nextEvent();
         if (event == EOF) break;
         if (event == OBJECT_START) {
-          handleObjectStart(parser, handler, values, new Stack<>(), recordStarted, null);
+          handleObjectStart(parser, handler, new LinkedHashMap<>(), new Stack<>(), recordStarted, null);
         } else if (event == ARRAY_START) {
           for (; ; ) {
             event = parser.nextEvent();
             if (event == ARRAY_END) break;
             if (event == OBJECT_START) {
-              handleObjectStart(parser, handler, values, new Stack<>(), recordStarted, null);
+              handleObjectStart(parser, handler, new LinkedHashMap<>(), new Stack<>(), recordStarted, null);
             }
           }
         }
@@ -350,6 +350,10 @@ public class JsonRecordReader {
               event = parser.nextEvent();
               if (event == ARRAY_END) break;
               if (event == OBJECT_START) {
+                // if single item in array will still be added as array
+                if(!values.containsKey(name)) {
+                  values.put(name, new ArrayList<>());
+                }
                 walkObject();
               }
             }
@@ -359,7 +363,7 @@ public class JsonRecordReader {
         void walkObject() throws IOException {
           if (node.isChildRecord) {
             node.handleObjectStart(parser,
-                (record, path) -> addChildDoc2ParentDoc(record, values),
+                (record, path) -> addChildDoc2ParentDoc(record, values, getPathSuffix(path)),
                 new LinkedHashMap<>(),
                 new Stack<>(),
                 true,
@@ -438,18 +442,18 @@ public class JsonRecordReader {
       }
     }
 
-    private void addChildDoc2ParentDoc(Map<String, Object> record, Map<String, Object> values) {
+    private void addChildDoc2ParentDoc(Map<String, Object> record, Map<String, Object> values, String key) {
       record =  Utils.getDeepCopy(record, 2);
-      Object oldVal = values.get(null);
+      Object oldVal = values.get(key);
       if (oldVal == null) {
-        values.put(null, record);
+        values.put(key, record);
       } else if (oldVal instanceof List) {
         ((List) oldVal).add(record);
       } else {
         ArrayList l = new ArrayList();
         l.add(oldVal);
         l.add(record);
-        values.put(null, l);
+        values.put(key, l);
       }
     }
 
@@ -486,6 +490,12 @@ public class JsonRecordReader {
       values.put(fieldName, l);
     }
 
+    // returns the last key of the path
+    private String getPathSuffix(String path) {
+      int indexOf = path.lastIndexOf("/");
+      if (indexOf == -1) return path;
+      return path.substring(indexOf + 1);
+    }
 
     @Override
     public String toString() {