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.accumulo;
  
  import java.util.Map.Entry;
  
  import org.apache.accumulo.core.client.Connector;
  import org.apache.accumulo.core.client.Scanner;
  import org.apache.accumulo.core.data.Key;
  import org.apache.accumulo.core.data.Value;
  import org.apache.apex.malhar.lib.db.AbstractStoreInputOperator;
  
  /**
   * Base input adapter, which reads data from persistence database and writes into output port(s).&nbsp; Subclasses should provide the
   * implementation of getting the tuples and scanner methods.
   *
   * <p>
   * This is an abstract class. Sub-classes need to implement {@link #getScanner()} and {@link #getTuple(Entry)}.
   * </p>
   * @displayName Abstract Accumulo Input
   * @category Input
   * @tags key value, accumulo
   * @since 1.0.4
   */
  public abstract class AbstractAccumuloInputOperator<T> extends AbstractStoreInputOperator<T, AccumuloStore>
  {
  
    public abstract T getTuple(Entry<Key, Value> entry);
  
    public abstract Scanner getScanner(Connector conn);
  
    public AbstractAccumuloInputOperator()
    {
      store = new AccumuloStore();
    }
  
    @Override
    public void emitTuples()
    {
      Connector conn = store.getConnector();
      Scanner scan = getScanner(conn);
  
      for (Entry<Key, Value> entry : scan) {
        T tuple = getTuple(entry);
        outputPort.emit(tuple);
      }
  
    }
  
  }
  