#22 Use generic type in BatchItemProcessor

Now the method buildAddLuceneWorks(List, Class<T>) is generic. This implementation done thanks to Stack Overflow. I've asked a question this morning : How to use generic type in a map? [duplicate] <http://stackoverflow.com/questions/37654228/how-to-use-generic-type-in-a-map>

us-address/src/main/java/io/github/mincongh/batch/BatchItemProcessor.java

@@ -103,7 +103,7 @@ public Object processItem(Object item) throws Exception {
                 // get data directly from the database.
                 .setHint("javax.persistence.cache.retrieveMode", "BYPASS")
                 .getResultList();
-        addWorks = buildAddLuceneWorks(addresses);
+        addWorks = buildAddLuceneWorks(addresses, Address.class);
         updateWorksCount(addWorks.size());
 
         return addWorks;
@@ -127,23 +127,28 @@ private void updateWorksCount(int currentCount) {
      * current mass indexer implementation.
      * 
      * @param entities entities obtained from JPA entity manager
+     * @param classOfEntity the class type of selected entities
      * @return a list of addLuceneWorks
      */
-    private <T> List<AddLuceneWork> buildAddLuceneWorks(List<T> entities) {
+    private <T> List<AddLuceneWork> buildAddLuceneWorks(List<T> entities, 
+            Class<T> classOfEntity) {
+
+        List<AddLuceneWork> addWorks = new LinkedList<>();
+        String tenantId = null;
+
         session = em.unwrap(Session.class);
         searchIntegrator = ContextHelper.getSearchintegrator(session);
         entityIndexBinding = searchIntegrator
                 .getIndexBindings()
-                .get(Address.class);
+                .get(classOfEntity);
         shardingStrategy = entityIndexBinding.getSelectionStrategy();
         indexingContext.setIndexShardingStrategy(shardingStrategy);
         docBuilder = entityIndexBinding.getDocumentBuilder();
         conversionContext = new ContextualExceptionBridgeHelper();
         sessionInitializer = new HibernateSessionLoadingInitializer(
                 (SessionImplementor) session
         );
-        String tenantId = null;
-        List<AddLuceneWork> addWorks = new LinkedList<>();
+
         for (T entity: entities) {
             Serializable id = session.getIdentifier(entity);
             TwoWayFieldBridge idBridge = docBuilder.getIdBridge();
@@ -168,6 +173,7 @@ private <T> List<AddLuceneWork> buildAddLuceneWorks(List<T> entities) {
             );
             addWorks.add(addWork);
         }
+
         return addWorks;
     }