| /** |
| * 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; |
| |
| import java.io.*; |
| |
| /** |
| * Output an arbitrary number of stderr lines before or after |
| * consuming the keys/values from stdin. |
| */ |
| public class StderrApp |
| { |
| /** |
| * Print preWriteLines to stderr, pausing sleep ms between each |
| * output, then consume stdin and echo it to stdout, then write |
| * postWriteLines to stderr. |
| */ |
| public static void go(int preWriteLines, int sleep, int postWriteLines) throws IOException { |
| go(preWriteLines, sleep, postWriteLines, false); |
| } |
| |
| public static void go(int preWriteLines, int sleep, int postWriteLines, boolean status) throws IOException { |
| BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); |
| String line; |
| |
| if (status) { |
| System.err.println("reporter:status:starting echo"); |
| } |
| |
| while (preWriteLines > 0) { |
| --preWriteLines; |
| System.err.println("some stderr output before reading input, " |
| + preWriteLines + " lines remaining, sleeping " + sleep); |
| try { |
| Thread.sleep(sleep); |
| } catch (InterruptedException e) {} |
| } |
| |
| while ((line = in.readLine()) != null) { |
| System.out.println(line); |
| } |
| |
| while (postWriteLines > 0) { |
| --postWriteLines; |
| System.err.println("some stderr output after reading input, lines remaining " |
| + postWriteLines); |
| } |
| } |
| |
| public static void main(String[] args) throws IOException { |
| if (args.length < 3) { |
| System.err.println("Usage: StderrApp PREWRITE SLEEP POSTWRITE [STATUS]"); |
| return; |
| } |
| int preWriteLines = Integer.parseInt(args[0]); |
| int sleep = Integer.parseInt(args[1]); |
| int postWriteLines = Integer.parseInt(args[2]); |
| boolean status = args.length > 3 ? Boolean.parseBoolean(args[3]) : false; |
| |
| go(preWriteLines, sleep, postWriteLines, status); |
| } |
| } |