| /** |
| * 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.sqoop.mapreduce.mainframe; |
| |
| import java.io.IOException; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.RecordReader; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| import org.apache.sqoop.mapreduce.DBWritable; |
| |
| import org.apache.sqoop.mapreduce.db.DBConfiguration; |
| |
| /** |
| * A RecordReader that reads records from a mainframe dataset. |
| * Emits LongWritables containing the record number as key and DBWritables as |
| * value. |
| */ |
| public abstract class MainframeDatasetRecordReader <T extends DBWritable> |
| extends RecordReader<LongWritable, T> { |
| private Class<T> inputClass; |
| private Configuration conf; |
| private MainframeDatasetInputSplit split; |
| private LongWritable key; |
| private T datasetRecord; |
| private long numberRecordRead; |
| private int datasetProcessed; |
| |
| private static final Log LOG = LogFactory.getLog( |
| MainframeDatasetRecordReader.class.getName()); |
| |
| @Override |
| public void initialize(InputSplit inputSplit, |
| TaskAttemptContext taskAttemptContext) |
| throws IOException, InterruptedException { |
| |
| split = (MainframeDatasetInputSplit)inputSplit; |
| conf = taskAttemptContext.getConfiguration(); |
| inputClass = (Class<T>) (conf.getClass( |
| DBConfiguration.INPUT_CLASS_PROPERTY, null)); |
| key = null; |
| datasetRecord = null; |
| numberRecordRead = 0; |
| datasetProcessed = 0; |
| } |
| |
| @Override |
| public boolean nextKeyValue() throws IOException, InterruptedException { |
| if (key == null) { |
| key = new LongWritable(); |
| } |
| if (datasetRecord == null) { |
| datasetRecord = ReflectionUtils.newInstance(inputClass, conf); |
| } |
| if (getNextRecord(datasetRecord)) { |
| numberRecordRead++; |
| key.set(numberRecordRead); |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public LongWritable getCurrentKey() throws IOException, InterruptedException { |
| return key; |
| } |
| |
| @Override |
| public T getCurrentValue() throws IOException, InterruptedException { |
| return datasetRecord; |
| } |
| |
| @Override |
| public float getProgress() throws IOException, InterruptedException { |
| return datasetProcessed / (float)split.getLength(); |
| } |
| |
| protected String getNextDataset() { |
| String datasetName = split.getNextDataset(); |
| if (datasetName != null) { |
| datasetProcessed++; |
| LOG.info("Starting transfer of " + datasetName); |
| } |
| return datasetName; |
| } |
| |
| protected Configuration getConfiguration() { |
| return conf; |
| } |
| |
| protected abstract boolean getNextRecord (T datasetRecord) throws IOException; |
| |
| } |