Added shard preference setting to query

Added shard preference setting to query.

Author: janghwan

module/app/com/github/cleverage/elasticsearch/IndexQuery.java

@@ -50,6 +50,7 @@ public class IndexQuery<T extends Index> {
     private int size = -1;
     private boolean explain = false;
     private boolean noField = false;
+    private String preference = null;
 
     public IndexQuery(Class<T> clazz) {
         Validate.notNull(clazz, "clazz cannot be null");
@@ -102,6 +103,18 @@ public IndexQuery<T> setExplain(boolean explain) {
         return this;
     }
 
+    /**
+     * Sets a preference of which shard replicas to execute the search request on.
+     * @param preference
+     *
+     * @return
+     */
+    public IndexQuery<T> setPreference(String preference) {
+        this.preference = preference;
+
+        return this;
+    }
+
     /**
      * Adds a facet
      *
@@ -259,6 +272,10 @@ public SearchRequestBuilder getSearchRequestBuilder(IndexQueryPath indexQueryPat
             request.setExplain(true);
         }
 
+        if (preference != null) {
+            request.setPreference(preference);
+        }
+
         if (IndexClient.config.showRequest) {
             if (StringUtils.isNotBlank(query)) {
                 Logger.debug("ElasticSearch : Query -> " + query);

module/app/com/github/cleverage/elasticsearch/ScalaHelpers.scala

@@ -209,6 +209,7 @@ object ScalaHelpers {
    * @param size the number of element to retrieve
    * @param explain flag used to activate explain
    * @param noField flag used to activate the "noField"
+   * @param preference preference of which shard replicas to execute the search request on
    * @tparam T Type into which the results will be converted
    */
   case class IndexQuery[T <: Indexable](
@@ -218,7 +219,8 @@ object ScalaHelpers {
     val from: Option[Int] = None,
     val size: Option[Int] = None,
     val explain: Option[Boolean] = None,
-    val noField: Boolean = false
+    val noField: Boolean = false,
+    val preference: Option[String] = None
   ) {
     def withBuilder(builder: QueryBuilder): IndexQuery[T] = copy(builder = builder)
     def addFacet(facet: FacetBuilder): IndexQuery[T] = copy(facetBuilders = facet :: facetBuilders)
@@ -227,6 +229,7 @@ object ScalaHelpers {
     def withSize(size: Int): IndexQuery[T] = copy(size = Some(size))
     def withExplain(explain: Boolean): IndexQuery[T] = copy(explain = Some(explain))
     def withNoField(noField: Boolean): IndexQuery[T] = copy(noField = noField)
+    def withPreference(preference: String): IndexQuery[T] = copy(preference = Some(preference))
 
     /**
      * Executes the query
@@ -281,6 +284,9 @@ object ScalaHelpers {
       if (noField) {
         request.setNoFields()
       }
+      preference.foreach {
+        request.setPreference(_)
+      }
       request
     }
   }