code: public Object find(Class entityClass, Object key)
      {
  
          EntityMetadata entityMetadata = KunderaMetadataManager.getEntityMetadata(kunderaMetadata, entityClass);
  
          String tableName = entityMetadata.getTableName();
          Class fieldClass = entityMetadata.getIdAttribute().getJavaType();
          String select_Query = SparkQueryConstants.SELECTALL_QUERY;
          select_Query = StringUtils.replace(select_Query, SparkQueryConstants.TABLE, tableName);
          StringBuilder builder = new StringBuilder(select_Query);
          builder.append(SparkQueryConstants.ADD_WHERE_CLAUSE);
          builder.append(dataHandler.getColumnName(entityMetadata.getIdAttribute()));
          builder.append(SparkQueryConstants.EQUALS);
  
          appendValue(builder, fieldClass, key);
          List result = this.executeQuery(builder.toString(), entityMetadata, null);
          return result.isEmpty() ? null : result.get(0);
      }
docs: /*
  (non-Javadoc)
  
  @see com.impetus.kundera.client.Client#find(java.lang.Class,
  java.lang.Object)