content: /**
   * 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 org.apache.apex.malhar.contrib.hbase;
  
  import java.io.IOException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.hadoop.hbase.client.Append;
  import org.apache.hadoop.hbase.client.HTable;
  
  import com.datatorrent.netlet.util.DTThrowable;
  
  /**
   * A base implementation of a StoreOutputOperator operator that stores tuples in HBase columns and offers
   * non-transactional append.&nbsp; Subclasses should provide implementation for appending operations. <br>
   * <p>
   * <br>
   * This class provides a HBase output operator that can be used to store tuples
   * in columns in a HBase table. It should be extended by the end-operator
   * developer. The extending class should implement operationAppend method and
   * provide a HBase Append metric object that specifies where and what to store
   * for the tuple in the table.<br>
   *
   * <br>
   * This class offers non-transactional append where the columns are append as
   * the tuples come in without waiting for the end window
   * @displayName Abstract HBase Append Output
   * @category Output
   * @tags hbase
   * @param <T>
   *            The tuple type
   * @since 1.0.2
   */
  public abstract class AbstractHBaseAppendOutputOperator<T> extends AbstractHBaseOutputOperator<T>
  {
    private static final transient Logger logger = LoggerFactory
        .getLogger(AbstractHBaseAppendOutputOperator.class);
  
    public AbstractHBaseAppendOutputOperator()
    {
      store = new HBaseStore();
    }
  
    @Override
    public void processTuple(T tuple, HTable table)
    {
      Append append = operationAppend(tuple);
      try {
        table.append(append);
      } catch (IOException e) {
        logger.error("Could not append tuple", e);
        DTThrowable.rethrow(e);
      }
  
    }
  
    /**
     * Return the HBase Append metric to store the tuple. The implementor should
     * return a HBase Append metric that specifies where and what to store for
     * the tuple in the table.
     *
     * @param t
     *            The tuple
     * @return The HBase Append metric
     */
    public abstract Append operationAppend(T t);
  }
  