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 org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.client.Get;
  import org.apache.hadoop.hbase.client.Result;
  
  /**
   * A base implementation of hbase input operator that retrieves tuples from HBase columns and provides get operation.&nbsp; Subclasses should provide implementation for get operation. <br>
   * <p>
   * <br>
   * This class provides a HBase input operator that can be used to retrieve tuples from columns in a
   * HBase table. The class should be extended by the end-operator developer. The extending class should
   * implement operationGet and getTuple methods. The operationGet method should provide a HBase Get metric
   * object that specifies where to retrieve tuples from a table. The getTuple method should map the contents
   * of a KeyValue from the Get result to a tuple.<br>
   *
   * <br>
   * @displayName HBase Get
   * @category Input
   * @tags hbase, get
   * @param <T> The tuple type
   * @since 0.3.2
   */
  public abstract class HBaseGetOperator<T> extends HBaseInputOperator<T>
  {
  
    @Override
    public void emitTuples()
    {
      try {
        Get get = operationGet();
        Result result = getStore().getTable().get(get);
        KeyValue[] kvs = result.raw();
        //T t = getTuple(kvs);
        //T t = getTuple(result);
        for (KeyValue kv : kvs) {
          T t = getTuple(kv);
          outputPort.emit(t);
        }
      } catch (Exception e) {
        throw new RuntimeException(e.getMessage());
      }
    }
  
    /**
     * Return a HBase Get metric to retrieve the tuple.
     * The implementor should return a HBase Get metric that specifies where to retrieve the tuple from
     * the table.
     *
     * @return The HBase Get metric
     */
    protected abstract Get operationGet();
  
    /**
     * Get a tuple from a HBase Get result.
     * The implementor should map the contents of a key value from a Get result and return a tuple.
     *
     * @param kv The key value
     * @return The tuple
     */
    protected abstract T getTuple(KeyValue kv);
  
  }
  