smart-hbase-dao/src/main/java/com/smartitengineering/dao/impl/hbase/spi/ObjectRowConverter.java

   1 /*
   2  * This is a common dao with basic CRUD operations and is not limited to any
   3  * persistent layer implementation
   4  *
   5  * Copyright (C) 2008  Imran M Yousuf (imyousuf@smartitengineering.com)
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 3 of the License, or (at your option) any later version.
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 package com.smartitengineering.dao.impl.hbase.spi;
  20
  21 import java.util.LinkedHashMap;
  22 import org.apache.hadoop.hbase.client.Put;
  23 import org.apache.hadoop.hbase.client.Result;
  24
  25 /**
  26  * Convert an object from object to HBase row and vice-versa
  27  * @author imyousuf
  28  */
  29 public interface ObjectRowConverter<T> {
  30
  31   /**
  32    * Convert an object to its representive class-row tuple. The Class will later
  33    * be used to determine which table to put the row into as well.
  34    * @param instance The object instance to convert into updateable rows
  35    * @return An ordered {@link java.util.Map} with related {@link Put}.
  36    */
  37   LinkedHashMap<Class, Put> objectToRows(T instance);
  38
  39   /**
  40    * Load an instance of the convertable object with the row. It might be needed
  41    * to load more {@link Result} to be able to load the object.
  42    * @param startRow The root row of this object.
  43    * @return Instance of the object from persisted {@link Result result(s)}
  44    */
  45   T rowsToObject(Result startRow);
  46
  47 }