reverted changes for auto-generated Id , added test cases for scan and scroll

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

@@ -388,15 +388,8 @@ public class ElasticsearchTemplate implements ElasticsearchOperations {
             String type = isBlank(query.getType())?
                     retrieveTypeFromPersistentEntity(query.getObject().getClass())[0] : query.getType();
 
-            IndexRequestBuilder indexRequestBuilder = null;
+            IndexRequestBuilder indexRequestBuilder = client.prepareIndex(indexName,type,query.getId())
-
+                    .setSource(objectMapper.writeValueAsString(query.getObject()));
-            if(query.getId() != null){
-                indexRequestBuilder = client.prepareIndex(indexName,type,query.getId());
-            }else {
-                indexRequestBuilder = client.prepareIndex(indexName,type);
-            }
-
-            indexRequestBuilder.setSource(objectMapper.writeValueAsString(query.getObject()));
 
             if(query.getVersion() != null){
                 indexRequestBuilder.setVersion(query.getVersion());

src/main/java/org/springframework/data/elasticsearch/repository/support/MappingElasticsearchEntityInformation.java

@@ -58,13 +58,10 @@ public class MappingElasticsearchEntityInformation<T, ID extends Serializable> e
     public ID getId(T entity) {
         ElasticsearchPersistentProperty id = entityMetadata.getIdProperty();
         try {
-            if(id != null){
             return (ID) BeanWrapper.create(entity, null).getProperty(id);
-            }
         } catch (Exception e) {
             throw new IllegalStateException("ID could not be resolved", e);
         }
-        return null;
     }
 
     @SuppressWarnings("unchecked")

src/test/java/org/springframework/data/elasticsearch/core/ElasticsearchTemplateTest.java

@@ -540,4 +540,76 @@ public class ElasticsearchTemplateTest {
         assertThat(sampleEntities.getTotalElements(), is(equalTo(1L)));
         assertThat(sampleEntities.getContent(), hasItem(sampleEntity1));
     }
+
+    @Test
+    public void shouldReturnResultsWithScanAndScroll(){
+        //given
+        List<IndexQuery> indexQueries = new ArrayList<IndexQuery>();
+        //first document
+        String documentId = randomNumeric(5);
+        SampleEntity sampleEntity1 = new SampleEntity();
+        sampleEntity1.setId(documentId);
+        sampleEntity1.setMessage("some message");
+        sampleEntity1.setVersion(System.currentTimeMillis());
+
+        IndexQuery indexQuery1 = new IndexQuery();
+        indexQuery1.setId(documentId);
+        indexQuery1.setObject(sampleEntity1);
+        indexQueries.add(indexQuery1);
+
+        //second document
+        String documentId2 = randomNumeric(5);
+        SampleEntity sampleEntity2 = new SampleEntity();
+        sampleEntity2.setId(documentId2);
+        sampleEntity2.setMessage("some message");
+        sampleEntity2.setVersion(System.currentTimeMillis());
+
+        IndexQuery indexQuery2 = new IndexQuery();
+        indexQuery2.setId(documentId2);
+        indexQuery2.setObject(sampleEntity2);
+
+        indexQueries.add(indexQuery2);
+        //when
+        elasticsearchTemplate.bulkIndex(indexQueries);
+        elasticsearchTemplate.refresh(SampleEntity.class,true);
+        //then
+
+        SearchQuery searchQuery = new SearchQuery();
+        searchQuery.addIndices("test-index");
+        searchQuery.addTypes("test-type");
+        searchQuery.setElasticsearchQuery(matchAllQuery());
+        searchQuery.setPageable(new PageRequest(0,1));
+
+        String scrollId = elasticsearchTemplate.scan(searchQuery,1000,false);
+        List<SampleEntity> sampleEntities = new ArrayList<SampleEntity>();
+        boolean hasRecords = true;
+        while (hasRecords){
+            Page<SampleEntity> page = elasticsearchTemplate.scroll(scrollId, 5000L , new ResultsMapper<SampleEntity>() {
+                @Override
+                public Page<SampleEntity> mapResults(SearchResponse response) {
+                    List<SampleEntity> chunk = new ArrayList<SampleEntity>();
+                    for(SearchHit searchHit : response.getHits()){
+                        if(response.getHits().getHits().length <= 0) {
+                            return null;
+                        }
+                        SampleEntity user = new SampleEntity();
+                        user.setId(searchHit.getId());
+                        user.setMessage((String)searchHit.getSource().get("message"));
+                        chunk.add(user);
+                    }
+                    return new PageImpl<SampleEntity>(chunk);
+                }
+
+            });
+            if(page != null) {
+                sampleEntities.addAll(page.getContent());
+                hasRecords = page.hasNextPage();
+            }
+            else{
+                hasRecords = false;
+            }
+
+        }
+        assertThat(sampleEntities.size(), is(equalTo(2)));
+    }
 }