contrib/src/main/java/com/datatorrent/contrib/hbase/HBasePOJOPutOperator.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.datatorrent.contrib.hbase;

import java.util.List;

import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.util.Bytes;

import com.datatorrent.lib.util.FieldValueGenerator;
import com.datatorrent.lib.util.FieldValueGenerator.FieldValueHandler;
import com.datatorrent.lib.util.PojoUtils;
import com.datatorrent.lib.util.PojoUtils.Getter;
import com.datatorrent.lib.util.TableInfo;

/**
 * @displayName HBase Output Operator
 * @category Output
 * @tags database, nosql, pojo, hbase
 * @since 3.0.0
 */
@Evolving
public class HBasePOJOPutOperator extends AbstractHBasePutOutputOperator<Object>
{
  private static final long serialVersionUID = 3241368443399294019L;

  private TableInfo<HBaseFieldInfo> tableInfo;

  private transient FieldValueGenerator<HBaseFieldInfo> fieldValueGenerator;

  private transient Getter<Object, String> rowGetter;
  private transient HBaseFieldValueHandler valueHandler = new HBaseFieldValueHandler();

  @Override
  public Put operationPut(Object obj)
  {
    final List<HBaseFieldInfo> fieldsInfo = tableInfo.getFieldsInfo();
    if (fieldValueGenerator == null) {
      fieldValueGenerator = FieldValueGenerator.getFieldValueGenerator(obj.getClass(), fieldsInfo);
    }
    if (rowGetter == null) {
      // use string as row id
      rowGetter = PojoUtils.createGetter(obj.getClass(), tableInfo.getRowOrIdExpression(), String.class);
    }

    Put put = new Put(Bytes.toBytes(rowGetter.get(obj)));
    valueHandler.put = put;
    fieldValueGenerator.handleFieldsValue(obj, valueHandler );
    return put;
  }

  /**
   * HBase table information
   */
  public TableInfo<HBaseFieldInfo> getTableInfo()
  {
    return tableInfo;
  }

  /**
   * HBase table information
   */
  public void setTableInfo(TableInfo<HBaseFieldInfo> tableInfo)
  {
    this.tableInfo = tableInfo;
  }


  public static class HBaseFieldValueHandler implements FieldValueHandler<HBaseFieldInfo>
  {
    public Put put;

    @Override
    public void handleFieldValue(HBaseFieldInfo fieldInfo, Object value)
    {
      put.add(Bytes.toBytes(fieldInfo.getFamilyName()), Bytes.toBytes(fieldInfo.getColumnName()), fieldInfo.toBytes( value ));
    }

  }
}