DATAES-17 : Add support to retrieve highlighted text in search result

Author: mohsinh

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

@@ -40,6 +40,7 @@
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.search.facet.Facet;
 import org.elasticsearch.search.facet.FacetBuilder;
+import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortOrder;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -388,6 +389,12 @@ private SearchResponse doSearch(SearchRequestBuilder searchRequest, SearchQuery
             }
         }
 
+        if(searchQuery.getHighlightFields() != null) {
+            for(HighlightBuilder.Field highlightField : searchQuery.getHighlightFields()){
+                searchRequest.addHighlightedField(highlightField);
+            }
+        }
+
         return searchRequest.setQuery(searchQuery.getQuery()).execute().actionGet();
     }
 

src/main/java/org/springframework/data/elasticsearch/core/query/NativeSearchQuery.java

@@ -17,7 +17,7 @@
 
 import org.elasticsearch.index.query.FilterBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
-import org.elasticsearch.search.facet.FacetBuilder;
+import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.springframework.data.elasticsearch.core.facet.FacetRequest;
 
@@ -37,6 +37,7 @@ public class NativeSearchQuery extends AbstractQuery implements SearchQuery {
 	private FilterBuilder filter;
 	private SortBuilder sort;
     private List<FacetRequest> facets;
+    private HighlightBuilder.Field[] highlightFields;
 
 
     public NativeSearchQuery(QueryBuilder query) {
@@ -54,6 +55,13 @@ public NativeSearchQuery(QueryBuilder query, FilterBuilder filter, SortBuilder s
 		this.sort = sort;
 	}
 
+    public NativeSearchQuery(QueryBuilder query, FilterBuilder filter, SortBuilder sort, HighlightBuilder.Field[] highlightFields) {
+        this.query = query;
+        this.filter = filter;
+        this.sort = sort;
+        this.highlightFields = highlightFields;
+    }
+
 	public QueryBuilder getQuery() {
 		return query;
 	}
@@ -64,6 +72,11 @@ public FilterBuilder getFilter() {
 
 	public SortBuilder getElasticsearchSort() {
 		return sort;
+    }
+
+    @Override
+    public HighlightBuilder.Field[] getHighlightFields() {
+        return highlightFields;
 	}
 
     public void addFacet(FacetRequest facetRequest){

src/main/java/org/springframework/data/elasticsearch/core/query/NativeSearchQueryBuilder.java

@@ -18,6 +18,7 @@
 import org.apache.commons.collections.CollectionUtils;
 import org.elasticsearch.index.query.FilterBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
+import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.elasticsearch.core.facet.FacetRequest;
@@ -39,6 +40,7 @@ public class NativeSearchQueryBuilder {
     private FilterBuilder filterBuilder;
     private SortBuilder sortBuilder;
     private List<FacetRequest> facetRequests = new ArrayList<FacetRequest>();
+    private HighlightBuilder.Field[] highlightFields;
     private Pageable pageable;
     private String[] indices;
     private String[] types;
@@ -64,6 +66,11 @@ public NativeSearchQueryBuilder withFacet(FacetRequest facetRequest) {
         return this;
     }
 
+    public NativeSearchQueryBuilder withHighlightFields(HighlightBuilder.Field... highlightFields){
+        this.highlightFields = highlightFields;
+        return this;
+    }
+
     public NativeSearchQueryBuilder withPageable(Pageable pageable) {
         this.pageable = pageable;
         return this;
@@ -85,7 +92,7 @@ public NativeSearchQueryBuilder withFields(String... fields) {
     }
 
     public NativeSearchQuery build() {
-        NativeSearchQuery nativeSearchQuery = new NativeSearchQuery(queryBuilder, filterBuilder, sortBuilder);
+        NativeSearchQuery nativeSearchQuery = new NativeSearchQuery(queryBuilder, filterBuilder, sortBuilder, highlightFields);
         if (pageable != null) {
             nativeSearchQuery.setPageable(pageable);
         }

src/main/java/org/springframework/data/elasticsearch/core/query/SearchQuery.java

@@ -17,7 +17,7 @@
 
 import org.elasticsearch.index.query.FilterBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
-import org.elasticsearch.search.facet.FacetBuilder;
+import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.springframework.data.elasticsearch.core.facet.FacetRequest;
 
@@ -38,4 +38,6 @@ public interface SearchQuery extends Query {
 	SortBuilder getElasticsearchSort();
 
     List<FacetRequest> getFacets();
+
+    HighlightBuilder.Field[] getHighlightFields();
 }

src/test/java/org/springframework/data/elasticsearch/SampleEntity.java

@@ -34,6 +34,7 @@ public class SampleEntity {
 	private String message;
 	private int rate;
 	private boolean available;
+    private String highlightedMessage;
 	@Version
 	private Long version;
 
@@ -77,6 +78,14 @@ public void setAvailable(boolean available) {
 		this.available = available;
 	}
 
+    public String getHighlightedMessage() {
+        return highlightedMessage;
+    }
+
+    public void setHighlightedMessage(String highlightedMessage) {
+        this.highlightedMessage = highlightedMessage;
+	}
+
 	public Long getVersion() {
 		return version;
 	}

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

@@ -19,6 +19,7 @@
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.index.engine.DocumentMissingException;
 import org.elasticsearch.search.SearchHit;
+import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.FieldSortBuilder;
 import org.elasticsearch.search.sort.SortOrder;
 import org.junit.Before;
@@ -27,7 +28,6 @@
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.elasticsearch.SampleEntity;
@@ -44,6 +44,7 @@
 import static org.elasticsearch.index.query.FilterBuilders.termFilter;
 import static org.elasticsearch.index.query.QueryBuilders.fieldQuery;
 import static org.elasticsearch.index.query.QueryBuilders.matchAllQuery;
+import static org.elasticsearch.index.query.QueryBuilders.termQuery;
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
@@ -778,4 +779,54 @@ public void shouldDoUpsertIfDocumentDoesNotExist(){
         assertThat(indexedEntity.getMessage(), is(message));
     }
 
+    @Test
+    public void shouldReturnHighlightedFieldsForGivenQueryAndFields(){
+
+        //given
+        String documentId = randomNumeric(5);
+        String actualMessage = "some test message";
+        String highlightedMessage = "some <em>test</em> message";
+
+        SampleEntity sampleEntity = new SampleEntity();
+        sampleEntity.setId(documentId);
+        sampleEntity.setMessage(actualMessage);
+        sampleEntity.setVersion(System.currentTimeMillis());
+
+        IndexQuery indexQuery = new IndexQuery();
+        indexQuery.setId(documentId);
+        indexQuery.setObject(sampleEntity);
+
+        elasticsearchTemplate.index(indexQuery);
+        elasticsearchTemplate.refresh(SampleEntity.class, true);
+
+        SearchQuery searchQuery = new NativeSearchQueryBuilder()
+                .withQuery(termQuery("message", "test"))
+                .withHighlightFields(new HighlightBuilder.Field("message"))
+                .build();
+
+        Page<SampleEntity> sampleEntities = elasticsearchTemplate.queryForPage(searchQuery, new ResultsMapper<SampleEntity>() {
+            @Override
+            public FacetedPage<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"));
+                    user.setHighlightedMessage(searchHit.getHighlightFields().get("message").fragments()[0].toString());
+                    chunk.add(user);
+                }
+                if(chunk.size() > 0){
+                    return new FacetedPageImpl<SampleEntity>(chunk);
+                }
+                return null;
+            }
+        });
+
+        assertThat(sampleEntities.getContent().get(0).getHighlightedMessage(), is(highlightedMessage));
+
+    }
+
 }