| /** |
| * 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.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 com.datatorrent.lib.db.AbstractStoreInputOperator; |
| /** |
| * Base input adapter, which reads data from persistence database and writes into output port(s). 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); |
| } |
| |
| } |
| |
| } |