| /** |
| * 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.hadoop.streaming.io; |
| |
| import java.io.DataInput; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.UnsupportedEncodingException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.streaming.PipeMapRed; |
| import org.apache.hadoop.util.LineReader; |
| |
| /** |
| * OutputReader that reads the client's output as text, interpreting each line |
| * as a key and outputting NullWritables for values. |
| */ |
| public class KeyOnlyTextOutputReader extends OutputReader<Text, NullWritable> { |
| |
| private LineReader lineReader; |
| private byte[] bytes; |
| private DataInput clientIn; |
| private Configuration conf; |
| private Text key; |
| private Text line; |
| |
| @Override |
| public void initialize(PipeMapRed pipeMapRed) throws IOException { |
| super.initialize(pipeMapRed); |
| clientIn = pipeMapRed.getClientInput(); |
| conf = pipeMapRed.getConfiguration(); |
| lineReader = new LineReader((InputStream)clientIn, conf); |
| key = new Text(); |
| line = new Text(); |
| } |
| |
| @Override |
| public boolean readKeyValue() throws IOException { |
| if (lineReader.readLine(line) <= 0) { |
| return false; |
| } |
| bytes = line.getBytes(); |
| key.set(bytes, 0, line.getLength()); |
| |
| line.clear(); |
| return true; |
| } |
| |
| @Override |
| public Text getCurrentKey() throws IOException { |
| return key; |
| } |
| |
| @Override |
| public NullWritable getCurrentValue() throws IOException { |
| return NullWritable.get(); |
| } |
| |
| @Override |
| public String getLastOutput() { |
| if (bytes != null) { |
| try { |
| return new String(bytes, "UTF-8"); |
| } catch (UnsupportedEncodingException e) { |
| return "<undecodable>"; |
| } |
| } else { |
| return null; |
| } |
| } |
| |
| } |