Highlighting Support

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/ElasticFeatureReader.java

@@ -110,6 +110,7 @@ private String nextHit() {
         final ElasticHit hit = searchHitIterator.next();
         final SimpleFeatureType type = getFeatureType();
         final Map<String, Object> source = hit.getSource();
+        final Map<String, List<String>> highlights = hit.getHighlight();
 
         final Float score;
         final Float relativeScore;
@@ -126,6 +127,12 @@ private String nextHit() {
             final String sourceName = (String) descriptor.getUserData().get(FULL_NAME);
 
             List<Object> values = hit.field(sourceName);
+
+            if (values == null && highlights != null && highlights.containsKey(sourceName)) {
+                // read field from source
+                values = Collections.unmodifiableList(highlights.get(sourceName));
+            }
+
             if (values == null && source != null) {
                 // read field from source
                 values = parserUtil.readField(source, sourceName);

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/ElasticFeatureSource.java

@@ -6,6 +6,7 @@
 
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.logging.Level;
@@ -217,6 +218,18 @@ private ElasticRequest prepareSearchRequest(Query query, boolean scroll) throws
             searchRequest.setSize(0);
         }
 
+        if (filterToElastic.gethighlights() != null) {
+            searchRequest.setHighlights(filterToElastic.gethighlights());
+
+            List<String> source = searchRequest.getSourceIncludes();
+            for (String key : filterToElastic.gethighlights().keySet()) {
+                if (source.contains(key))
+                {
+                    source.remove(key);
+                }
+            }
+        }
+
         return searchRequest;
     }
 

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/ElasticHit.java

@@ -32,6 +32,8 @@ class ElasticHit {
     @JsonProperty("fields")
     private Map<String,List<Object>> fields;
 
+    private Map<String,List<String>> highlight;
+
     public String getIndex() {
         return index;
     }
@@ -60,4 +62,11 @@ public List<Object> field(String name) {
         return this.fields != null ? this.fields.get(name) : null;
     }
 
+    public Map<String, List<String>> getHighlight() {
+        return highlight;
+    }
+
+    public void setHighlight(Map<String, List<String>> highlight) {
+        this.highlight = highlight;
+    }
 }

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/ElasticRequest.java

@@ -15,6 +15,8 @@ class ElasticRequest {
 
     private Map<String,Map<String,Map<String,Object>>> aggregations;
 
+    private Map<String, Object> highlights;
+
     private Integer size;
 
     private Integer from;
@@ -49,6 +51,14 @@ public void setAggregations(Map<String,Map<String,Map<String,Object>>> aggregati
         this.aggregations = aggregations;
     }
 
+    public Map<String, Object> getHighlights() {
+        return highlights;
+    }
+
+    public void setHighlights(Map<String, Object> highlights) {
+        this.highlights = highlights;
+    }
+
     public Integer getSize() {
         return size;
     }

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/FilterToElastic.java

@@ -157,6 +157,7 @@ class FilterToElastic implements FilterVisitor, ExpressionVisitor {
     Map<String,Map<String,Map<String,Object>>> aggregations;
 
     private final FilterToElasticHelper helper;
+    private Map<String, Object> highlights;
 
     private String key;
 
@@ -1232,6 +1233,20 @@ void addViewParams(Query query) {
                             throw new FilterToElasticException("Unable to parse aggregation", e);
                         }
                     }
+                } else if (entry.getKey().equalsIgnoreCase("highlight")) {
+                    final ObjectMapper mapper = new ObjectMapper();
+                    final TypeReference<Map<String, Object>> type;
+                    type = new TypeReference<Map<String, Object>>() {};
+                    final String value = entry.getValue();
+                    try {
+                        this.highlights = mapper.readValue(value, type);
+                    } catch (Exception e) {
+                        try {
+                            this.highlights = mapper.readValue(ElasticParserUtil.urlDecode(value), type);
+                        } catch (Exception e2) {
+                            throw new FilterToElasticException("Unable to parse aggregation", e);
+                        }
+                    }
                 }
             }
         }
@@ -1318,4 +1333,7 @@ public Map<String,Map<String,Map<String,Object>>> getAggregations() {
         return aggregations;
     }
 
+    public Map<String, Object> gethighlights() {
+        return highlights;
+    }
 }

gt-elasticsearch/src/main/java/mil/nga/giat/data/elasticsearch/RestElasticClient.java

@@ -194,6 +194,10 @@ public ElasticResponse search(String searchIndices, String type, ElasticRequest
             requestBody.put("aggregations", request.getAggregations());
         }
 
+        if (request.getHighlights() != null) {
+            requestBody.put("highlight", request.getHighlights());
+        }
+
         return parseResponse(performRequest("POST", pathBuilder.toString(), requestBody));
     }